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Voziyan P, Brown KL, Uppuganti S, Leser M, Rose KL, Nyman JS. A map of glycation and glycoxidation sites in collagen I of human cortical bone: Effects of sex and type 2 diabetes. Bone 2024; 187:117209. [PMID: 39047900 DOI: 10.1016/j.bone.2024.117209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 07/19/2024] [Accepted: 07/21/2024] [Indexed: 07/27/2024]
Abstract
Complications of diabetes is a major health problem affecting multiple organs including bone, where the chronic disease increases the risk of fragility fractures. One hypothesis suggests a pathogenic role for hyperglycemia-induced modification of proteins, a.k.a. advanced glycation end products (AGEs), resulting in structural and functional damage to bone extracellular matrix (ECM). Evidence supporting this hypothesis has been limited by the lack of comprehensive information about the location of AGEs that accumulate in vivo at specific sites within the proteins of bone ECM. Analyzing extracts from cortical bone of cadaveric femurs by liquid chromatography tandem mass spectrometry, we generated a quantitative AGE map of human collagen I for male and female adult donors with and without diabetes. The map describes the chemical nature, sequence position, and levels of four major physiological AGEs, e.g. carboxymethyllysine, and an AGE precursor fructosyllysine within the collagen I triple-helical region. The important features of the map are: 1) high map reproducibility in the individual bone extracts, i.e. 20 male and 20 female donors; 2) localization of modifications to distinct clusters: 10 clusters containing 34 AGE sites in male donors and 9 clusters containing 28 sites in female donors; 3) significant increases in modification levels in diabetes at multiple sites: 26 out of 34 sites in males and in 17 out of 28 sites in females; and 4) generally higher modification levels in male vs. female donors. Moreover, the AGE levels at multiple individual sites correlated with total bone pentosidine levels in male but not in female donors. Molecular dynamics simulations and molecular modeling predicted significant impact of modifications on solvent exposure, charge distribution, and hydrophobicity of the triple helix as well as disruptions to the structure of collagen I fibril. In summary, the AGE map of collagen I revealed diabetes-induced, sex-specific non-enzymatic modifications at distinct triple helical sites that can disrupt collagen structure, thus proposing a specific mechanism of AGE contribution to diabetic complications in human bone.
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Affiliation(s)
- Paul Voziyan
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.
| | - Kyle L Brown
- Vanderbilt Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Sasidhar Uppuganti
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Micheal Leser
- Department of Biochemistry and Proteomics Core, Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Kristie Lindsey Rose
- Department of Biochemistry and Proteomics Core, Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Jeffry S Nyman
- Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
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2
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Moura NMM, Guedes S, Salvador D, Oliveira H, Alves MQ, Paradis N, Wu C, Neves MGPMS, Ramos CIV. Oncogenic and telomeric G-quadruplexes: Targets for porphyrin-triphenylphosphonium conjugates. Int J Biol Macromol 2024; 277:134126. [PMID: 39097044 DOI: 10.1016/j.ijbiomac.2024.134126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 08/05/2024]
Abstract
DNA chains with sequential guanine (G) repeats can lead to the formation of G-quadruplexes (G4), which are found in functional DNA and RNA regions like telomeres and oncogene promoters. The development of molecules with adequate structural features to selectively stabilize G4 structures can counteract cell immortality, highly described for cancer cells, and also downregulate transcription events underlying cell apoptosis and/or senescence processes. We describe here, the efficiency of four highly charged porphyrins-phosphonium conjugates to act as G4 stabilizing agents. The spectrophotometric results allowed to select the conjugates P2-PPh3 and P3-PPh3 as the most promising ones to stabilize selectively G4 structures. Molecular dynamics simulation experiments were performed and support the preferential binding of P2-PPh3 namely to MYC and of P3-PPh3 to KRAS. The ability of both ligands to block the activity of Taq polymerase was confirmed and also their higher cytotoxicity against the two melanoma cell lines A375 and SK-MEL-28 than to immortalized skin keratinocytes. Both ligands present efficient cellular uptake, nuclear co-localization and high ability to generate 1O2 namely when interacting with G4 structure. The obtained data points the synthesized porphyrins as promising ligands to be used in a dual approach that can combine G4 stabilization and Photodynamic therapy (PDT).
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Affiliation(s)
- Nuno M M Moura
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Sofia Guedes
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Diana Salvador
- CESAM-Centre for Environmental and Marine Studies, Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal; CICECO, Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Helena Oliveira
- CESAM-Centre for Environmental and Marine Studies, Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Mariana Q Alves
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Nicholas Paradis
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, United States of America
| | - Chun Wu
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, United States of America
| | - M Graça P M S Neves
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Catarina I V Ramos
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
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Hatch HW, Bergonzo C, Blanco MA, Yuan G, Grudinin S, Lund M, Curtis JE, Grishaev AV, Liu Y, Shen VK. Anisotropic coarse-grain Monte Carlo simulations of lysozyme, lactoferrin, and NISTmAb by precomputing atomistic models. J Chem Phys 2024; 161:094113. [PMID: 39234967 DOI: 10.1063/5.0224809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 08/16/2024] [Indexed: 09/06/2024] Open
Abstract
We develop a multiscale coarse-grain model of the NIST Monoclonal Antibody Reference Material 8671 (NISTmAb) to enable systematic computational investigations of high-concentration physical instabilities such as phase separation, clustering, and aggregation. Our multiscale coarse-graining strategy captures atomic-resolution interactions with a computational approach that is orders of magnitude more efficient than atomistic models, assuming the biomolecule can be decomposed into one or more rigid bodies with known, fixed structures. This method reduces interactions between tens of thousands of atoms to a single anisotropic interaction site. The anisotropic interaction between unique pairs of rigid bodies is precomputed over a discrete set of relative orientations and stored, allowing interactions between arbitrarily oriented rigid bodies to be interpolated from the precomputed table during coarse-grained Monte Carlo simulations. We present this approach for lysozyme and lactoferrin as a single rigid body and for the NISTmAb as three rigid bodies bound by a flexible hinge with an implicit solvent model. This coarse-graining strategy predicts experimentally measured radius of gyration and second osmotic virial coefficient data, enabling routine Monte Carlo simulation of medically relevant concentrations of interacting proteins while retaining atomistic detail. All methodologies used in this work are available in the open-source software Free Energy and Advanced Sampling Simulation Toolkit.
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Affiliation(s)
- Harold W Hatch
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Christina Bergonzo
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Biomolecular Structure and Function Group, Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Marco A Blanco
- Discovery Pharmaceutical Sciences, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania 19486, USA
| | - Guangcui Yuan
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Sergei Grudinin
- CNRS, Grenoble INP, LJK, Université Grenoble Alpes, 38000 Grenoble, France
| | - Mikael Lund
- Division of Computational Chemistry, Lund University, Lund, Sweden
| | - Joseph E Curtis
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Alexander V Grishaev
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Biomolecular Structure and Function Group, Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Yun Liu
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, College of Engineering, University of Delaware, Newark, Delaware 19711, USA
| | - Vincent K Shen
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
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Piomponi V, Krepl M, Sponer J, Bussi G. Molecular Simulations to Investigate the Impact of N6-Methylation in RNA Recognition: Improving Accuracy and Precision of Binding Free Energy Prediction. J Phys Chem B 2024. [PMID: 39240243 DOI: 10.1021/acs.jpcb.4c03397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
N6-Methyladenosine (m6A) is a prevalent RNA post-transcriptional modification that plays crucial roles in RNA stability, structural dynamics, and interactions with proteins. The YT521-B (YTH) family of proteins, which are notable m6A readers, functions through its highly conserved YTH domain. Recent structural investigations and molecular dynamics (MD) simulations have shed light on the mechanism of recognition of m6A by the YTHDC1 protein. Despite advancements, using MD to predict the stabilization induced by m6A on the free energy of binding between RNA and YTH proteins remains challenging due to inaccuracy of the employed force field and limited sampling. For instance, simulations often fail to sufficiently capture the hydration dynamics of the binding pocket. This study addresses these challenges through an innovative methodology that integrates metadynamics, alchemical simulations, and force-field refinement. Importantly, our research identifies hydration of the binding pocket as giving only a minor contribution to the binding free energy and emphasizes the critical importance of precisely tuning force-field parameters to experimental data. By employing a fitting strategy built on alchemical calculations, we refine the m6A partial charge parameters, thereby enabling the simultaneous reproduction of N6 methylation on both the protein binding free energy and the thermodynamic stability of nine RNA duplexes. Our findings underscore the sensitivity of binding free energies to partial charges, highlighting the necessity for thorough parametrization and validation against experimental observations across a range of structural contexts.
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Affiliation(s)
- Valerio Piomponi
- Scuola Internazionale Superiore di Studi Avanzati, SISSA, Via Bonomea 265, Trieste 34136, Italy
- Area Science Park, località Padriciano, 99, Trieste 34149, Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolská 135, Brno 612 00, Czech Republic
| | - Jiri Sponer
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolská 135, Brno 612 00, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, SISSA, Via Bonomea 265, Trieste 34136, Italy
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5
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Liu HY, Mei KJ, Borrelli WR, Schwartz BJ. Simulating the Competitive Ion Pairing of Hydrated Electrons with Chaotropic Cations. J Phys Chem B 2024; 128:8557-8566. [PMID: 39178349 DOI: 10.1021/acs.jpcb.4c04290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2024]
Abstract
Experiments show that the absorption spectrum of the hydrated electron (ehyd-) blue-shifts in electrolyte solutions compared with what is seen in pure water. This shift has been assigned to the ehyd-'s competitive ion-pairing interactions with the salt cation relative to the salt anion based on the ions' positions on the Hofmeister series. Remarkably, little work has been done investigating the ehyd-'s behavior when the salts have chaotropic cations, which should greatly change the ion-pairing interactions given that the ehyd- is a champion chaotrope. In this work, we remedy this by using mixed quantum/classical simulations to analyze the behavior of two different models of the ehyd- in aqueous RbF and RbI electrolyte solutions as a function of salt concentration. We find that the magnitude of the salt-induced spectral blue-shift is determined by a combination of the number of chaotropic Rb+ cations near the ehyd- and the number of salt anions near those cations so that the spectrum of the ehyd- directly reflects its local environment. We also find that the use of a soft-cavity ehyd- model predicts stronger competitive interactions with Rb+ relative to I- than a more traditional hard cavity model, leading to different predicted spectral shifts that should provide a way to distinguish between the two models experimentally. Our simulations predict that at the same concentration, salts with chaotropic cations should produce larger spectral blue-shifts than salts with kosmotropic cations. We also found that at high salt concentrations with chaotropic cations, the predicted blue-shift is greater when the salt anion is kosmotropic instead of chaotropic. Our goal is for this work to inspire experimentalists to make such measurements, which will help provide a spectroscopic means to distinguish between simulations models that predict different hydration structures for the ehyd-.
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Affiliation(s)
- Hannah Y Liu
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Kenneth J Mei
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - William R Borrelli
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
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Risheh A, Rebel A, Nerenberg PS, Forouzesh N. Calculation of protein-ligand binding entropies using a rule-based molecular fingerprint. Biophys J 2024; 123:2839-2848. [PMID: 38481102 DOI: 10.1016/j.bpj.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/21/2023] [Accepted: 03/08/2024] [Indexed: 03/28/2024] Open
Abstract
The use of fast in silico prediction methods for protein-ligand binding free energies holds significant promise for the initial phases of drug development. Numerous traditional physics-based models (e.g., implicit solvent models), however, tend to either neglect or heavily approximate entropic contributions to binding due to their computational complexity. Consequently, such methods often yield imprecise assessments of binding strength. Machine learning models provide accurate predictions and can often outperform physics-based models. They, however, are often prone to overfitting, and the interpretation of their results can be difficult. Physics-guided machine learning models combine the consistency of physics-based models with the accuracy of modern data-driven algorithms. This work integrates physics-based model conformational entropies into a graph convolutional network. We introduce a new neural network architecture (a rule-based graph convolutional network) that generates molecular fingerprints according to predefined rules specifically optimized for binding free energy calculations. Our results on 100 small host-guest systems demonstrate significant improvements in convergence and preventing overfitting. We additionally demonstrate the transferability of our proposed hybrid model by training it on the aforementioned host-guest systems and then testing it on six unrelated protein-ligand systems. Our new model shows little difference in training set accuracy compared to a previous model but an order-of-magnitude improvement in test set accuracy. Finally, we show how the results of our hybrid model can be interpreted in a straightforward fashion.
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Affiliation(s)
- Ali Risheh
- Department of Computer Science, California State University, Los Angeles, California
| | - Alles Rebel
- Department of Computer Science, California State University, Los Angeles, California
| | - Paul S Nerenberg
- Kravis Department of Integrated Sciences, Claremont McKenna College, Claremont, California
| | - Negin Forouzesh
- Department of Computer Science, California State University, Los Angeles, California.
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7
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Pant P. Flexible RNA aptamers as inhibitors of Bacillus anthracis ribosomal protein S8: Insights from molecular dynamics simulations. Biophys Chem 2024; 312:107273. [PMID: 38850843 DOI: 10.1016/j.bpc.2024.107273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 06/02/2024] [Indexed: 06/10/2024]
Abstract
Bacillus anthracis, the causative agent of anthrax, poses a substantial threat to public health and national security, and is recognized as a potential bioweapon due to its capacity to form resilient spores with enduring viability. Inhalation or ingestion of even minute quantities of aerosolized spores can lead to widespread illness and fatalities, underscoring the formidable lethality of the bacterium. With an untreated mortality rate of 100%, Bacillus anthracis is a disconcerting candidate for bioterrorism. In response to this critical scenario, we employed state-of-the-art computational tools to conceive and characterize flexible RNA aptamer therapeutics tailored for anthrax. The foundational structure of the flexible RNA aptamers was designed by removing the C2'-C3' in each nucleotide unit. Leveraging the crystal structure of Bacillus anthracis ribosomal protein S8 complexed with an RNA aptamer, we explored the structural, dynamic, and energetic aspects of the modified RNA aptamer - S8 protein complexes through extensive all-atom explicit-solvent molecular dynamics simulations (400 ns, 3 replicas each), followed by drawing comparisons to the control system. Our findings demonstrate the enhanced binding competencies of the flexible RNA aptamers to the S8 protein via better shape complementarity and improved H-bond network compared to the control RNA aptamer. This research offers valuable insights into the development of RNA aptamer therapeutics targeting Bacillus anthracis, paving the way for innovative strategies to mitigate the impact of this formidable pathogen.
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Affiliation(s)
- Pradeep Pant
- Department of Biotechnology, School of Engineering and Applied Sciences, Bennett University, Greater Noida, U.P., India.
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Liu Z, Lin L, Li T, Premadasa UI, Hong K, Ma YZ, Sacci RL, Katsaras J, Carrillo JM, Doughty B, Collier CP. Physicochemical control of solvation and molecular assembly of charged amphiphilic oligomers at air-aqueous interfaces. J Colloid Interface Sci 2024; 669:552-560. [PMID: 38729003 DOI: 10.1016/j.jcis.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/07/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024]
Abstract
HYPOTHESIS Understanding the rules that control the assembly of nanostructured soft materials at interfaces is central to many applications. We hypothesize that electrolytes can be used to alter the hydration shell of amphiphilic oligomers at the air-aqueous interface of Langmuir films, thereby providing a means to control the formation of emergent nanostructures. EXPERIMENTS Three representative salts - (NaF, NaCl, NaSCN) were studied for mediating the self-assembly of oligodimethylsiloxane methylimidazolium (ODMS-MIM+) amphiphiles in Langmuir films. The effects of the different salts on the nanostructure assembly of these films were probed using vibrational sum frequency generation (SFG) spectroscopy and Langmuir trough techniques. Experimental data were supported by atomistic molecular dynamic simulations. FINDINGS Langmuir trough surface pressure - area isotherms suggested a surprising effect on oligomer assembly, whereby the presence of anions affects the stability of the interfacial layer irrespective of their surface propensities. In contrast, SFG results implied a strong anion effect that parallels the surface activity of anions. These seemingly contradictory trends are explained by anion driven tail dehydration resulting in increasingly heterogeneous systems with entangled ODMS tails and appreciable anion penetration into the complex interfacial layer comprised of headgroups, tails, and interfacial water molecules. These findings provide physical and chemical insight for tuning a wide range of interfacial assemblies.
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Affiliation(s)
- Zening Liu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Lu Lin
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Tianyu Li
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, United States
| | - Uvinduni I Premadasa
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Kunlun Hong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Ying-Zhong Ma
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Robert L Sacci
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - John Katsaras
- Neutron Scattering Division and Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States; Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Jan-Michael Carrillo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States.
| | - Benjamin Doughty
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States.
| | - C Patrick Collier
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States.
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Murray MT, Wetmore SD. Unlocking precision in aptamer engineering: a case study of the thrombin binding aptamer illustrates why modification size, quantity, and position matter. Nucleic Acids Res 2024:gkae729. [PMID: 39217472 DOI: 10.1093/nar/gkae729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 08/02/2024] [Accepted: 08/23/2024] [Indexed: 09/04/2024] Open
Abstract
The thrombin binding aptamer (TBA) is a prototypical platform used to understand the impact of chemically-modified nucleotides on aptamer stability and target affinity. To provide structural insight into the experimentally-observed effects of modification size, location, and number on aptamer performance, long time-scale molecular dynamics (MD) simulations were performed on multiple binding orientations of TBA-thrombin complexes that contain a large, flexible tryptophan thymine derivative (T-W) or a truncated analogue (T-K). Depending on modification position, T-W alters aptamer-target binding orientations, fine-tunes aptamer-target interactions, strengthens networks of nucleic acid-protein contacts, and/or induces target conformational changes to enhance binding. The proximity and 5'-to-3' directionality of nucleic acid structural motifs also play integral roles in the behavior of the modifications. Modification size can differentially influence target binding by promoting more than one aptamer-target binding pose. Multiple modifications can synergistically strengthen aptamer-target binding by generating novel nucleic acid-protein structural motifs that are unobtainable for single modifications. By studying a diverse set of modified aptamers, our work uncovers design principles that must be considered in the future development of aptamers containing chemically-modified nucleotides for applications in medicine and biotechnology, highlighting the value of computational studies in nucleic acids research.
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Affiliation(s)
- Makay T Murray
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
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10
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Trewhella J, Vachette P, Larsen AH. Benchmarking predictive methods for small-angle X-ray scattering from atomic coordinates of proteins using maximum likelihood consensus data. IUCRJ 2024; 11:762-779. [PMID: 38989800 PMCID: PMC11364021 DOI: 10.1107/s205225252400486x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 05/23/2024] [Indexed: 07/12/2024]
Abstract
Stimulated by informal conversations at the XVII International Small Angle Scattering (SAS) conference (Traverse City, 2017), an international team of experts undertook a round-robin exercise to produce a large dataset from proteins under standard solution conditions. These data were used to generate consensus SAS profiles for xylose isomerase, urate oxidase, xylanase, lysozyme and ribonuclease A. Here, we apply a new protocol using maximum likelihood with a larger number of the contributed datasets to generate improved consensus profiles. We investigate the fits of these profiles to predicted profiles from atomic coordinates that incorporate different models to account for the contribution to the scattering of water molecules of hydration surrounding proteins in solution. Programs using an implicit, shell-type hydration layer generally optimize fits to experimental data with the aid of two parameters that adjust the volume of the bulk solvent excluded by the protein and the contrast of the hydration layer. For these models, we found the error-weighted residual differences between the model and the experiment generally reflected the subsidiary maxima and minima in the consensus profiles that are determined by the size of the protein plus the hydration layer. By comparison, all-atom solute and solvent molecular dynamics (MD) simulations are without the benefit of adjustable parameters and, nonetheless, they yielded at least equally good fits with residual differences that are less reflective of the structure in the consensus profile. Further, where MD simulations accounted for the precise solvent composition of the experiment, specifically the inclusion of ions, the modelled radius of gyration values were significantly closer to the experiment. The power of adjustable parameters to mask real differences between a model and the structure present in solution is demonstrated by the results for the conformationally dynamic ribonuclease A and calculations with pseudo-experimental data. This study shows that, while methods invoking an implicit hydration layer have the unequivocal advantage of speed, care is needed to understand the influence of the adjustable parameters. All-atom solute and solvent MD simulations are slower but are less susceptible to false positives, and can account for thermal fluctuations in atomic positions, and more accurately represent the water molecules of hydration that contribute to the scattering profile.
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Affiliation(s)
- Jill Trewhella
- School of Life and Environmental SciencesUniversity of SydneyNSW2006Australia
| | - Patrice Vachette
- Institute for Integrative Biology of the Cell (12BC)Université Paris-Saclay, CEA, CNRSGif-sur-YvetteParis91198France
| | - Andreas Haahr Larsen
- Department of NeuroscienceUniversity of CopenhagenBlegdamsvej 32200CopenhagenDenmark
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11
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Liang Y, Zhang Y, Huang Y, Xu C, Chen J, Zhang X, Huang B, Gan Z, Dong X, Huang S, Li C, Jia S, Zhang P, Yuan Y, Zhang H, Wang Y, Yuan B, Bao Y, Xiao S, Xiong M. Helicity-directed recognition of bacterial phospholipid via radially amphiphilic antimicrobial peptides. SCIENCE ADVANCES 2024; 10:eadn9435. [PMID: 39213359 PMCID: PMC11364095 DOI: 10.1126/sciadv.adn9435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 07/25/2024] [Indexed: 09/04/2024]
Abstract
The fundamental differences in phospholipids between bacterial and mammalian cell membranes present remarkable opportunities for antimicrobial design. However, it is challenging to distinguish bacterial anionic phospholipid phosphatidylglycerol (PG) from mammalian anionic phosphatidylserine (PS) with the same net charge. Here, we report a class of radially amphiphilic α helix antimicrobial peptides (RAPs) that can selectively discriminate PG from PS, relying on the helix structure. The representative RAP, L10-MMBen, can direct the rearrangement of PG vesicles into a lamellar structure with its helix axis parallel to the PG membrane surface. The helical structure imparts both the thermodynamic and kinetic advantages of L10-MMBen/PG assembly, and the hiding of hydrophobic regions in RAPs is crucial for PG recognition. L10-MMBen exhibits high selectivity against bacteria depending on PG recognition, showing low in vivo toxicity and significant treatment efficacy in mice infection models. Our study introduces a helicity-direct bacterial phospholipid recognition paradigm for designing highly selective antimicrobial peptides.
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Affiliation(s)
- Yangbin Liang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Yuhao Zhang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Yu Huang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Cheng Xu
- Songshan Lake Materials Laboratory, Institute of Physics, Chinese Academy of Sciences, Dongguan, 523808, P. R. China
| | - Jingxian Chen
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Xinshuang Zhang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Bingchuan Huang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Zhanhui Gan
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China
| | - Xuehui Dong
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China
| | - Songyin Huang
- Biotherapy Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, P. R. China
| | - Chengrun Li
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Shuyi Jia
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
| | - Pengfei Zhang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
| | - Yueling Yuan
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou, Guangdong 510006, P. R. China
| | - Houbing Zhang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
| | - Yucai Wang
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China
| | - Bing Yuan
- Songshan Lake Materials Laboratory, Institute of Physics, Chinese Academy of Sciences, Dongguan, 523808, P. R. China
| | - Yan Bao
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, P. R. China
| | - Shiyan Xiao
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Menghua Xiong
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China
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12
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Bali SK, Hall K, Massoud RI, Almeida NMS, Wilson AK. Interaction of Per- and Polyfluoroalkyl Substances with Estrogen Receptors in Rainbow Trout ( Oncorhynchus mykiss): An In Silico Investigation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39207093 DOI: 10.1021/acs.est.4c03648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Fresh water sources, including lakes, such as the Great Lakes, are some of the most important ecosystems in the world. Despite the importance of these lakes, there is increasing concern about the presence of per- and polyfluoroalkyl substances (PFAS)─among the most prevalent contaminants of our time─due to the ability of PFAS to bioaccumulate and persist in the environment, as well as to its linkages to detrimental human and animal health effects. In this study, PFAS exposure on rainbow trout (Oncorhynchus mykiss) is examined at the molecular level, focusing on the impact of PFAS binding on the alpha (α) and beta (β) estrogen receptors (ERs) using molecular dynamics simulations, binding free energy calculations, and structural analysis. ERs are involved in fundamental physiological processes, including reproductive system development, muscle regeneration, and immunity. This study shows that PFAS binds to both the estrogen α and estrogen β receptors, albeit via different binding modes, due to a modification of an amino acid in the binding site as a result of a reorientation of residues in the binding pocket. As ER overactivation can occur through environmental toxins and pollutants, this study provides insights into the influence of different types of PFAS on protein function.
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Affiliation(s)
- Semiha Kevser Bali
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Kyleen Hall
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Rana I Massoud
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Nuno M S Almeida
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Angela K Wilson
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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13
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Gwyther REA, Côté S, Lee CS, Miao H, Ramakrishnan K, Palma M, Dafydd Jones D. Optimising CNT-FET biosensor design through modelling of biomolecular electrostatic gating and its application to β-lactamase detection. Nat Commun 2024; 15:7482. [PMID: 39209826 PMCID: PMC11362306 DOI: 10.1038/s41467-024-51325-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Carbon nanotube field effect transistors (CNT-FET) hold great promise as next generation miniaturised biosensors. One bottleneck is modelling how proteins, with their distinctive electrostatic surfaces, interact with the CNT-FET to modulate conductance. Using advanced sampling molecular dynamics combined with non-canonical amino acid chemistry, we model protein electrostatic potential imparted on single walled CNTs (SWCNTs). We focus on using β-lactamase binding protein (BLIP2) as the receptor as it binds the antibiotic degrading enzymes, β-lactamases (BLs). BLIP2 is attached via the single selected residue to SWCNTs using genetically encoded phenyl azide photochemistry. Our devices detect two different BLs, TEM-1 and KPC-2, with each BL generating distinct conductance profiles due to their differing surface electrostatic profiles. Changes in conductance match the model electrostatic profile sampled by the SWCNTs on BL binding. Thus, our modelling approach combined with residue-specific receptor attachment could provide a general approach for systematic CNT-FET biosensor construction.
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Affiliation(s)
- Rebecca E A Gwyther
- Molecular Biosciences Division, School of Biosciences Cardiff University, Cardiff, UK
| | - Sébastien Côté
- Département de Physique, Faculté des Arts et des Sciences, Université de Montréal, Montréal, QC, Canada.
- Département de Physique, Cégep de Saint-Jérôme, Saint-Jérôme, QC, Canada.
| | - Chang-Seuk Lee
- Department of Chemistry, Queen Mary University of London, London, UK
- Department of Chemistry, Seoul Women's University, Seoul, Republic of Korea
| | - Haosen Miao
- Department of Chemistry, Queen Mary University of London, London, UK
| | - Krithika Ramakrishnan
- Molecular Biosciences Division, School of Biosciences Cardiff University, Cardiff, UK
| | - Matteo Palma
- Department of Chemistry, Queen Mary University of London, London, UK.
| | - D Dafydd Jones
- Molecular Biosciences Division, School of Biosciences Cardiff University, Cardiff, UK.
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14
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Chen J, Wang J, Yang W, Zhao L, Hu G. Conformations of KRAS4B Affected by Its Partner Binding and G12C Mutation: Insights from GaMD Trajectory-Image Transformation-Based Deep Learning. J Chem Inf Model 2024. [PMID: 39197061 DOI: 10.1021/acs.jcim.4c01174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2024]
Abstract
Binding of partners and mutations highly affects the conformational dynamics of KRAS4B, which is of significance for deeply understanding its function. Gaussian accelerated molecular dynamics (GaMD) simulations followed by deep learning (DL) and principal component analysis (PCA) were carried out to probe the effect of G12C and binding of three partners NF1, RAF1, and SOS1 on the conformation alterations of KRAS4B. DL reveals that G12C and binding of partners result in alterations in the contacts of key structure domains, such as the switch domains SW1 and SW2 together with the loops L4, L5, and P-loop. Binding of NF1, RAF1, and SOS1 constrains the structural fluctuation of SW1, SW2, L4, and L5; on the contrary, G12C leads to the instability of these four structure domains. The analyses of free energy landscapes (FELs) and PCA also show that binding of partners maintains the stability of the conformational states of KRAS4B while G12C induces greater mobility of the switch domains SW1 and SW2, which produces significant impacts on the interactions of GTP with SW1, L4, and L5. Our findings suggest that partner binding and G12C play important roles in the activity and allosteric regulation of KRAS4B, which may theoretically aid in further understanding the function of KRAS4B.
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Affiliation(s)
- Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan 250357, China
- Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Jian Wang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Wanchun Yang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Lu Zhao
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Guodong Hu
- Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
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15
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Mou X, Liu K, He L, Li S. Mechanical response of double-stranded DNA: Bend, twist, and overwind. J Chem Phys 2024; 161:085102. [PMID: 39177087 DOI: 10.1063/5.0216585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 08/09/2024] [Indexed: 08/24/2024] Open
Abstract
We employed all-atom molecular dynamics simulations to explore the mechanical response of bending, twisting, and overwinding for double-stranded DNA (dsDNA). We analyzed the bending and twisting deformations, as well as their stiffnesses, using the tilt, roll, and twist modes under stretching force. Findings indicate that the roll and twist angles vary linearly with the stretching force but show opposite trends. The tilt, roll, and twist elastic moduli are considered constants, while the coupling between roll and twist modes slightly decreases under stretching force. The effect of the stretching force on the roll and twist modes, including both their deformations and elasticities, exhibits sequence-dependence, with symmetry around the base pair step. Furthermore, we examined the overwinding path and mechanism of dsDNA from the perspective of the stiffness matrix, based on the tilt, roll, and twist modes. The correlations among tilt, roll, and twist angles imply an alternative overwinding pathway via twist-roll coupling when dsDNA is stretched, wherein entropic contribution prevails.
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Affiliation(s)
- Xuankang Mou
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Kai Liu
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Linli He
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Shiben Li
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China
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16
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Gonzalez M, Guberman-Pfeffer MJ, Koone JC, Dashnaw CM, Lato TJ, Shaw BF. Proton-coupled electron transfer at a mis-metalated zinc site detected with protein charge ladders. Phys Chem Chem Phys 2024. [PMID: 39193659 DOI: 10.1039/d4cp01989j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2024]
Abstract
Distinguishing proton-coupled electron transfer (PCET) from uncoupled electron transfer (ET) in proteins can be challenging. A recent investigation [J. C. Koone, M. Simmang, D. L. Saenger, M. L. Hunsicker-Wang and B. F. Shaw, J. Am. Chem. Soc., 145, 16488-16497] reported that protein charge ladders and capillary electrophoresis can distinguish between single ET, PCET, and two-proton coupled ET (2PCET) by directly measuring the change in protein net charge upon reduction/oxidation (ΔZET). The current study used similar methods to assess PCET in zinc-free, "double copper" superoxide dismutase-1 (4Cu-SOD1), where one copper is bound at the copper site of each monomer and one copper is bound at the bridging zinc site, resulting in a quasi-type III Cu center. At pH 7.4, the net charge (Z) of the 4Cu-SOD1 dimer was unaffected by reduction of all four Cu2+ ions, i.e., ΔZ4ET = -0.09 ± 0.05 per dimer (-0.02 ± 0.01 per copper atom). These values suggest that PCET is taking place at all four Cu atoms of the homodimer. Molecular dynamics and Poisson-Boltzmann calculations suggest that a metal-coordinating histidine at the zinc site (His71) is the proton acceptor. These data show how ligands of a naturally occurring zinc site can help facilitate PCET when the right redox metal is bound.
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Affiliation(s)
- Mayte Gonzalez
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, USA.
| | | | - Jordan C Koone
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, USA.
| | - Chad M Dashnaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, USA.
| | - Travis J Lato
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, USA.
| | - Bryan F Shaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, USA.
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17
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Sousa JPM, Ramos MJ, Fernandes PA. QM/MM Study of the Reaction Mechanism of L-Tyrosine Hydroxylation Catalyzed by the Enzyme CYP76AD1. J Phys Chem B 2024. [PMID: 39185757 DOI: 10.1021/acs.jpcb.4c05209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
We have studied the hydroxylation mechanism of l-Tyr by the heme-dependent enzyme CYP76AD1 from the sugar beet (Beta vulgaris). This enzyme has a promising biotechnological application in modified yeast strains to produce medicinal alkaloids, an alternative to the traditional opium poppy harvest. A generative machine learning software based on AlphaFold was used to build the structure of CYP76AD1 since there are no structural data for this specific enzyme. After model validation, l-Tyr was docked in the active site of CYP76AD1 to assemble the reactive complex, whose catalytic distances remained stable throughout the 100 ns of MD simulation. Subsequent QM/MM calculations elucidated that l-Tyr hydroxylation occurs in two steps: hydrogen abstraction from l-Tyr by CpdI, forming an l-Tyr radical, and subsequent radical rebound, corresponding to a rate-limiting step of 16.0 kcal·mol-1. Our calculations suggest that the hydrogen abstraction step should occur in the doublet state, while the radical rebound should happen in the quartet state. The clarification of the reaction mechanism of CYP76AD1 provides insights into the rational optimization of the biosynthesis of alkaloids to eliminate the use of opium poppy.
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Affiliation(s)
- João P M Sousa
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências Universidade do Porto, Rua do Campo Alegre, s/n, Porto 4169-007, Portugal
| | - Maria J Ramos
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências Universidade do Porto, Rua do Campo Alegre, s/n, Porto 4169-007, Portugal
| | - Pedro A Fernandes
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências Universidade do Porto, Rua do Campo Alegre, s/n, Porto 4169-007, Portugal
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18
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Marien J, Prévost C, Sacquin-Mora S. nP-Collabs: Investigating Counterion-Mediated Bridges in the Multiply Phosphorylated Tau-R2 Repeat. J Chem Inf Model 2024; 64:6570-6582. [PMID: 39092904 DOI: 10.1021/acs.jcim.4c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Tau is an intrinsically disordered (IDP) microtubule-associated protein (MAP) that plays a key part in microtubule assembly and organization. The function of tau can be regulated by multiple phosphorylation sites. These post-translational modifications are known to decrease the binding affinity of tau for microtubules, and abnormal tau phosphorylation patterns are involved in Alzheimer's disease. Using all-atom molecular dynamics simulations, we compared the conformational landscapes explored by the tau R2 repeat domain (which comprises a strong tubulin binding site) in its native state and with multiple phosphorylations on the S285, S289, and S293 residues, with four different standard force field (FF)/water model combinations. We find that the different parameters used for the phosphate groups (which can be more or less flexible) in these FFs and the specific interactions between bulk cations and water lead to the formation of a specific type of counterion bridge, termed nP-collab (for nphosphate collaboration, with n being an integer), where counterions form stable structures binding with two or three phosphate groups simultaneously. The resulting effect of nP-collabs on the tau-R2 conformational space differs when using sodium or potassium cations and is likely to impact the peptide overall dynamics and how this MAP interacts with tubulins. We also investigated the effect of phosphoresidue spacing and ionic concentration by modeling polyalanine peptides containing two phosphoserines located one-six residues apart. Three new metrics specifically tailored for IDPs (proteic Menger curvature, local curvature, and local flexibility) were introduced, which allow us to fully characterize the impact of nP-collabs on the dynamics of disordered peptides at the residue level.
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Affiliation(s)
- Jules Marien
- Laboratoire de Biochimie Théorique, Université Paris-Cité, CNRS, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Chantal Prévost
- Laboratoire de Biochimie Théorique, Université Paris-Cité, CNRS, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Sophie Sacquin-Mora
- Laboratoire de Biochimie Théorique, Université Paris-Cité, CNRS, 13 Rue Pierre et Marie Curie, 75005 Paris, France
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19
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Damberger FF, Krepl M, Arora R, Beusch I, Maris C, Dorn G, Šponer J, Ravindranathan S, Allain FHT. N-terminal domain of polypyrimidine-tract binding protein is a dynamic folding platform for adaptive RNA recognition. Nucleic Acids Res 2024:gkae713. [PMID: 39180402 DOI: 10.1093/nar/gkae713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 08/14/2024] [Indexed: 08/26/2024] Open
Abstract
The N-terminal RNA recognition motif domain (RRM1) of polypyrimidine tract binding protein (PTB) forms an additional C-terminal helix α3, which docks to one edge of the β-sheet upon binding to a stem-loop RNA containing a UCUUU pentaloop. Importantly, α3 does not contact the RNA. The α3 helix therefore represents an allosteric means to regulate the conformation of adjacent domains in PTB upon binding structured RNAs. Here we investigate the process of dynamic adaptation by stem-loop RNA and RRM1 using NMR and MD in order to obtain mechanistic insights on how this allostery is achieved. Relaxation data and NMR structure determination of the free protein show that α3 is partially ordered and interacts with the domain transiently. Stem-loop RNA binding quenches fast time scale dynamics and α3 becomes ordered, however microsecond dynamics at the protein-RNA interface is observed. MD shows how RRM1 binding to the stem-loop RNA is coupled to the stabilization of the C-terminal helix and helps to transduce differences in RNA loop sequence into changes in α3 length and order. IRES assays of full length PTB and a mutant with altered dynamics in the α3 region show that this dynamic allostery influences PTB function in cultured HEK293T cells.
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Affiliation(s)
- Fred F Damberger
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
- Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 00, Czech Republic
| | - Rajika Arora
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Irene Beusch
- Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Georg Dorn
- Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 00, Czech Republic
| | | | - Frédéric H-T Allain
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
- Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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20
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Wang R, Tiwary P. Atomic scale insights into NaCl nucleation in nanoconfined environments. Chem Sci 2024:d4sc04042b. [PMID: 39234215 PMCID: PMC11367593 DOI: 10.1039/d4sc04042b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Accepted: 08/23/2024] [Indexed: 09/06/2024] Open
Abstract
In this work we examine the nucleation from NaCl aqueous solutions within nano-confined environments, employing enhanced sampling molecular dynamics simulations integrated with machine learning-derived reaction coordinates. Through our simulations, we successfully induce phase transitions between solid, liquid, and a hydrated phase, typically observed at lower temperatures in bulk environments. Interestingly, while generally speaking nano-confinement serves to stabilize the solid phase and elevate melting points, there are subtle variations in the thermodynamics of competing phases with the precise extent of confinement. Our simulations explain these findings by underscoring the significant role of water, alongside ion aggregation and subtle, anisotropic dielectric behavior, in driving nucleation within nano-confined environments. This report thus provides a framework for sampling, analyzing and understanding nucleation processes under nano-confinement.
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Affiliation(s)
- Ruiyu Wang
- Institute for Physical Science and Technology, University of Maryland College Park MD 20742 USA
| | - Pratyush Tiwary
- Institute for Physical Science and Technology, University of Maryland College Park MD 20742 USA
- Department of Chemistry and Biochemistry, University of Maryland College Park MD 20742 USA
- University of Maryland Institute for Health Computing Bethesda Maryland 20852 USA
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21
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Sumino A, Sumikama T, Zhao Y, Flechsig H, Umeda K, Kodera N, Konno H, Hattori M, Shibata M. High-Speed Atomic Force Microscopy Reveals Fluctuations and Dimer Splitting of the N-Terminal Domain of GluA2 Ionotropic Glutamate Receptor-Auxiliary Subunit Complex. ACS NANO 2024. [PMID: 39180186 DOI: 10.1021/acsnano.4c06295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2024]
Abstract
α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid glutamate receptors (AMPARs) enable rapid excitatory synaptic transmission by localizing to the postsynaptic density of glutamatergic spines. AMPARs possess large extracellular N-terminal domains (NTDs), which are crucial for AMPAR clustering at synaptic sites. However, the dynamics of NTDs and the molecular mechanism governing their synaptic clustering remain elusive. Here, we employed high-speed atomic force microscopy (HS-AFM) to directly visualize the conformational dynamics of NTDs in the GluA2 subunit complexed with TARP γ2 in lipid environments. HS-AFM videos of GluA2-γ2 in the resting and activated/open states revealed fluctuations in NTD dimers. Conversely, in the desensitized/closed state, the two NTD dimers adopted a separated conformation with less fluctuation. Notably, we observed individual NTD dimers transitioning into monomers, with extended monomeric states in the activated/open state. Molecular dynamics simulations provided further support, confirming the energetic stability of the monomeric NTD states within lipids. This NTD-dimer splitting resulted in subunit exchange between the receptors and increased the number of interaction sites with synaptic protein neuronal pentraxin 1 (NP1). Moreover, our HS-AFM studies revealed that NP1 forms a ring-shaped octamer through N-terminal disulfide bonds and binds to the tip of the NTD. These findings suggest a molecular mechanism in which NP1, upon forming an octamer, is secreted into the synaptic region and binds to the tip of the GluA2 NTD, thereby bridging and clustering multiple AMPARs. Thus, our findings illuminate the critical role of NTD dynamics in the synaptic clustering of AMPARs and contribute valuable insights into the fundamental processes of synaptic transmission.
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Affiliation(s)
- Ayumi Sumino
- Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Takashi Sumikama
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Yimeng Zhao
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, and Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Yangpu District, Shanghai 200438, China
- Human Phenome Institute, Fudan University, Yangpu District, Shanghai 200438, China
| | - Holger Flechsig
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Kenichi Umeda
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Noriyuki Kodera
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Hiroki Konno
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, and Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Yangpu District, Shanghai 200438, China
| | - Mikihiro Shibata
- Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
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22
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Fu XL, Zheng F, Xie SJ, Ji YL, Gao CJ. The mechanisms underlying Li +/Mg 2+ separation in ZIF-8 under an electric field from atomistic simulations. Phys Chem Chem Phys 2024; 26:22220-22229. [PMID: 39129471 DOI: 10.1039/d4cp02045f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
In this study, we explore the mass transfer and separation mechanism of Li+ and Mg2+ confined within the flexible nanoporous zeolite imidazolate framework ZIF-8 under the influence of an electric field, employing molecular dynamics simulation. Our results highlight that the electric field accelerates the dehydration process of ions and underscore the critical importance of ZIF-8 framework flexibility in determining the separation selectivity of the ZIF-8 membrane. The electric field is shown to diminish ion hydration in the confined space of ZIF-8, notably disrupting the orientation of water molecules in the first hydration shells of ions, leading to an asymmetrical ionic hydration structure characterized by the uniform alignment of water dipoles. Furthermore, despite the geometrical constraints imposed by the ZIF-8 framework, the electric field significantly enhances ionic mobility. Notably, the less stable hydration shell of Li+ facilitates its rapid, dehydration-induced transit through ZIF-8 nanopores, unlike Mg2+, whose stable hydration shell impedes dehydration. Further investigation into the structural characteristics of the six-ring windows traversed by Li+ and Mg2+ ions reveals distinct mechanisms of passage: for Mg2+ ions, significant window expansion is necessary, while for Li+ ions, the mechanism involves both window expansion and partial dehydration. These findings reveal the profound impact of the electric field and framework flexibility on the separation of Li+ and Mg2+, offering critical insights for the potential application of flexible nanoporous materials in the selective extraction of Li+ from salt-lake brine.
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Affiliation(s)
- Xiang-Long Fu
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Fan Zheng
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Shi-Jie Xie
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Yan-Li Ji
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Cong-Jie Gao
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
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23
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Radwan M, Guo T, Carvajal EG, Bekkema BAR, Cairo CW. Bioisosteres at C9 of 2-Deoxy-2,3-didehydro- N-acetyl Neuraminic Acid Identify Selective Inhibitors of NEU3. J Med Chem 2024; 67:13594-13603. [PMID: 39101748 DOI: 10.1021/acs.jmedchem.3c02186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
Human neuraminidases play critical roles in many physiological and pathological processes. Humans have four isoenzymes of NEU, making selective inhibitors important tools to investigate the function of individual isoenzymes. A typical scaffold for NEU inhibitors is 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA) where C9 modifications can be critical for potency and selectivity against human NEU. To design improved DANA analogues, we generated a library of compounds with either a short alkyl chain or a biphenyl substituent linked to the C9 position through one of six amide bioisosteres. Bioisostere linkers included triazole, urea, thiourea, carbamate, thiocarbamate, and sulfonamide groups. Within this library, we identified a C9 biphenyl carbamate derivative (963) that showed high selectivity and potency for NEU3 (Ki = 0.12 ± 0.01 μM). In contrast, NEU1 and NEU4 isoenzymes preferred amide and triazole linkers, respectively. Finally, analogues with urea, sulfonamide, and amide linkers showed enhanced inhibitory activity for a bacterial NEU, NanI from Clostridium perfringens.
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Affiliation(s)
- Mostafa Radwan
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tianlin Guo
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Elisa G Carvajal
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Benjamin A R Bekkema
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Christopher W Cairo
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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24
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Zheng CC, Chen YL, Dong HL, Zhang XH, Tan ZJ. Effect of ethanol on the elasticities of double-stranded RNA and DNA revealed by magnetic tweezers and simulations. J Chem Phys 2024; 161:075101. [PMID: 39145565 DOI: 10.1063/5.0211869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 07/29/2024] [Indexed: 08/16/2024] Open
Abstract
The elasticities of double-stranded (ds) DNA and RNA, which are critical to their biological functions and applications in materials science, can be significantly modulated by solution conditions such as ions and temperature. However, there is still a lack of a comprehensive understanding of the role of solvents in the elasticities of dsRNA and dsDNA in a comparative way. In this work, we explored the effect of ethanol solvent on the elasticities of dsRNA and dsDNA by magnetic tweezers and all-atom molecular dynamics simulations. We found that the bending persistence lengths and contour lengths of dsRNA and dsDNA decrease monotonically with the increase in ethanol concentration. Furthermore, the addition of ethanol weakens the positive twist-stretch coupling of dsRNA, while promotes the negative twist-stretch coupling of dsDNA. Counter-intuitively, the lower dielectric environment of ethanol causes a significant re-distribution of counterions and enhanced ion neutralization, which overwhelms the enhanced repulsion along dsRNA/dsDNA, ultimately leading to the softening in bending for dsRNA and dsDNA. Moreover, for dsRNA, ethanol causes slight ion-clamping across the major groove, which weakens the major groove-mediated twist-stretch coupling, while for dsDNA, ethanol promotes the stretch-radius correlation due to enhanced ion binding and consequently enhances the helical radius-mediated twist-stretch coupling.
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Affiliation(s)
- Chen-Chen Zheng
- School of Physics and Technology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yun-Long Chen
- School of Physics and Technology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Hai-Long Dong
- School of Physics and Technology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xing-Hua Zhang
- School of Physics and Technology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhi-Jie Tan
- School of Physics and Technology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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25
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Duenas-Herrera M, Bonthuis DJ, Loche P, Netz RR, Scalfi L. Force field for halide and alkali ions in water based on single-ion and ion-pair thermodynamic properties for a wide range of concentrations. J Chem Phys 2024; 161:074506. [PMID: 39158049 DOI: 10.1063/5.0217998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 07/20/2024] [Indexed: 08/20/2024] Open
Abstract
A classical non-polarizable force field for the common halide (F-, Cl-, Br-, and I-) and alkali (Li+, Na+, K+, and Cs+) ions in SPC/E water is presented. This is an extension of the force field developed by Loche et al. for Na+, K+, Cl-, and Br- (JPCB 125, 8581-8587, 2021): in the present work, we additionally optimize Lennard-Jones parameters for Li+, I-, Cs+, and F- ions. Li+ and F- are particularly challenging ions to model due to their small size. The force field is optimized with respect to experimental solvation free energies and activity coefficients, which are the necessary and sufficient quantities to accurately reproduce the electrolyte thermodynamics. Good agreement with experimental reference data is achieved for a wide range of concentrations (up to 4 mol/l). We find that standard Lorentz-Berthelot combination rules are sufficient for all ions except F-, for which modified combination rules are necessary. With the optimized parameters, we show that, although the force field is only optimized based on thermodynamic properties, structural properties are reproduced quantitatively, while ion diffusion coefficients are in qualitative agreement with experimental values.
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Affiliation(s)
- Maria Duenas-Herrera
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Douwe Jan Bonthuis
- Institute of Theoretical and Computational Physics, Graz University of Technology, Graz, Austria
| | - Philip Loche
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Laboratory of Computational Science and Modeling, IMX, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland
| | - Roland R Netz
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Laura Scalfi
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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26
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Taghavi A, Chen JL, Wang Z, Sinnadurai K, Salthouse D, Ozon M, Feri A, Fountain MA, Choudhary S, Childs-Disney JL, Disney MD. NMR structures and magnetic force spectroscopy studies of small molecules binding to models of an RNA CAG repeat expansion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.20.608150. [PMID: 39229124 PMCID: PMC11370455 DOI: 10.1101/2024.08.20.608150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
RNA repeat expansions fold into stable structures and cause microsatellite diseases such as Huntington's disease (HD), myotonic dystrophy type 1 (DM1), and spinocerebellar ataxias (SCAs). The trinucleotide expansion of r(CAG), or r(CAG) exp , causes both HD and SCA3, and the RNA's toxicity has been traced to its translation into polyglutamine (polyQ; HD) as well as aberrant pre-mRNA alternative splicing (SCA3 and HD). Previously, a small molecule, 1 , was discovered that binds to r(CAG) exp and rescues aberrant pre-mRNA splicing in patient-derived fibroblasts by freeing proteins bound to the repeats. Here, we report the structures of single r(CAG) repeat motif (5'C A G/3'G A C where the underlined adenosines form a 1×1 nucleotide internal loop) in complex with 1 and two other small molecules via nuclear magnetic resonance (NMR) spectroscopy combined with simulated annealing. Compound 2 was designed based on the structure of 1 bound to the RNA while 3 was selected as a diverse chemical scaffold. The three complexes, although adopting different 3D binding pockets upon ligand binding, are stabilized by a combination of stacking interactions with the internal loop's closing GC base pairs, hydrogen bonds, and van der Waals interactions. Molecular dynamics (MD) simulations performed with NMR-derived restraints show that the RNA is stretched and bent upon ligand binding with significant changes in propeller-twist and opening. Compound 3 has a distinct mode of binding by insertion into the helix, displacing one of the loop nucleotides into the major groove and affording a rod-like shape binding pocket. In contrast, 1 and 2 are groove binders. A series of single molecule magnetic force spectroscopy studies provide a mechanistic explanation for how bioactive compounds might rescue disease-associated cellular phenotypes.
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27
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Mendez-Otalvaro E, Kopec W, de Groot BL. Effect of two activators on the gating of a K 2P channel. Biophys J 2024:S0006-3495(24)00528-9. [PMID: 39161093 DOI: 10.1016/j.bpj.2024.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/27/2024] [Accepted: 08/09/2024] [Indexed: 08/21/2024] Open
Abstract
TWIK-related potassium channel 1 (TREK1), a two-pore-domain mammalian potassium (K+) channel, regulates the resting potential across cell membranes, presenting a promising therapeutic target for neuropathy treatment. The gating of this channel converges in the conformation of the narrowest part of the pore: the selectivity filter (SF). Various hypotheses explain TREK1 gating modulation, including the dynamics of loops connecting the SF with transmembrane helices and the stability of hydrogen bond (HB) networks adjacent to the SF. Recently, two small molecules (Q6F and Q5F) were reported as activators that affect TREK1 by increasing its open probability in single-channel current measurements. Here, using molecular dynamics simulations, we investigate the effect of these ligands on the previously proposed modulation mechanisms of TREK1 gating compared to the apo channel. Our findings reveal that loop dynamics at the upper region of the SF exhibit only a weak correlation with permeation events/nonpermeation periods, whereas the HB network behind the SF appears more correlated. These nonpermeation periods arise from both distinct mechanisms: a C-type inactivation (resulting from dilation at the top of the SF), which has been described previously, and a carbonyl flipping in an SF binding site. We find that, besides the prevention of C-type inactivation in the channel, the ligands increase the probability of permeation by modulating the dynamics of the carbonyl flipping, influenced by a threonine residue at the bottom of the SF. These results offer insights for rational ligand design to optimize the gating modulation of TREK1 and related K+ channels.
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Affiliation(s)
- Edward Mendez-Otalvaro
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Wojciech Kopec
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Department of Chemistry, Queen Mary University of London, London, United Kingdom.
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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28
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Phulera S, Dickson CJ, Schwalen CJ, Khoshouei M, Cassell SJ, Sun Y, Condos T, Whicher J, Weihofen WA. Scorpion α-toxin LqhαIT specifically interacts with a glycan at the pore domain of voltage-gated sodium channels. Structure 2024:S0969-2126(24)00284-3. [PMID: 39181123 DOI: 10.1016/j.str.2024.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/13/2024] [Accepted: 07/30/2024] [Indexed: 08/27/2024]
Abstract
Voltage-gated sodium (Nav) channels sense membrane potential and drive cellular electrical activity. The deathstalker scorpion α-toxin LqhαIT exerts a strong action potential prolonging effect on Nav channels. To elucidate the mechanism of action of LqhαIT, we determined a 3.9 Å cryoelectron microscopy (cryo-EM) structure of LqhαIT in complex with the Nav channel from Periplaneta americana (NavPas). We found that LqhαIT binds to voltage sensor domain 4 and traps it in an "S4 down" conformation. The functionally essential C-terminal epitope of LqhαIT forms an extensive interface with the glycan scaffold linked to Asn330 of NavPas that augments a small protein-protein interface between NavPas and LqhαIT. A combination of molecular dynamics simulations, structural comparisons, and prior mutagenesis experiments demonstrates the functional importance of this toxin-glycan interaction. These findings establish a structural basis for the specificity achieved by scorpion α-toxins and reveal the conserved glycan as an essential component of the toxin-binding epitope.
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Affiliation(s)
- Swastik Phulera
- Discovery Sciences, Novartis Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Callum J Dickson
- Global Discovery Chemistry, Novartis Biomedical Research, 181 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Christopher J Schwalen
- Global Discovery Chemistry, Novartis Biomedical Research, 181 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Maryam Khoshouei
- Discovery Sciences, Novartis Biomedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Samantha J Cassell
- Discovery Sciences, Novartis Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Yishan Sun
- Neuroscience, Novartis Biomedical Research, 22 Windsor St, Cambridge, MA 02139, USA
| | - Tara Condos
- Discovery Sciences, Novartis Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Jonathan Whicher
- Discovery Sciences, Novartis Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - Wilhelm A Weihofen
- Discovery Sciences, Novartis Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA.
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29
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Muscat S, Martino G, Manigrasso J, Marcia M, De Vivo M. On the Power and Challenges of Atomistic Molecular Dynamics to Investigate RNA Molecules. J Chem Theory Comput 2024. [PMID: 39150960 DOI: 10.1021/acs.jctc.4c00773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2024]
Abstract
RNA molecules play a vital role in biological processes within the cell, with significant implications for science and medicine. Notably, the biological functions exerted by specific RNA molecules are often linked to the RNA conformational ensemble. However, the experimental characterization of such three-dimensional RNA structures is challenged by the structural heterogeneity of RNA and by its multiple dynamic interactions with binding partners such as small molecules, proteins, and metal ions. Consequently, our current understanding of the structure-function relationship of RNA molecules is still limited. In this context, we highlight molecular dynamics (MD) simulations as a powerful tool to complement experimental efforts on RNAs. Despite the recognized limitations of current force fields for RNA MD simulations, examining the dynamics of selected RNAs has provided valuable functional insights into their structures.
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Affiliation(s)
- Stefano Muscat
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Gianfranco Martino
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Jacopo Manigrasso
- Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, 431 50 Mölndal, Sweden
| | - Marco Marcia
- European Molecular Biology Laboratory Grenoble, 71 Avenue des Martyrs, 38042 Grenoble, France
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, 751 23 Uppsala, Sweden
- Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Marco De Vivo
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
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30
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Brossier C, Jardou M, Janaszkiewicz A, Firoud D, Petit I, Arnion H, Pinault E, Sauvage FL, Druilhe A, Picard N, Di Meo F, Marquet P, Lawson R. Gut microbiota biotransformation of drug glucuronides leading to gastrointestinal toxicity: Therapeutic potential of bacterial β-glucuronidase inhibition in mycophenolate-induced enteropathy. Life Sci 2024; 351:122792. [PMID: 38857657 DOI: 10.1016/j.lfs.2024.122792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/28/2024] [Accepted: 06/04/2024] [Indexed: 06/12/2024]
Abstract
AIMS Drug-induced enteropathy is often associated with the therapeutic use of certain glucuronidated drugs. One such drug is mycophenolic acid (MPA), a well-established immunosuppressant of which gastrointestinal adverse effects are a major concern. The role of bacterial β-glucuronidase (β-G) from the gut microbiota in MPA-induced enteropathy has recently been discovered. Bacterial β-G hydrolyzes MPAG, the glucuronide metabolite of MPA excreted in the bile, leading to the digestive accumulation of MPA that would favor in turn these adverse events. We therefore hypothesized that taming bacterial β-G activity might reduce MPA digestive exposure and prevent its toxicity. MAIN METHODS By using a multiscale approach, we evaluated the effect of increasing concentrations of MPA on intestinal epithelial cells (Caco-2 cell line) viability, proliferation, and migration. Then, we investigated the inhibitory properties of amoxapine, a previously described bacterial β-G inhibitor, by using molecular dynamics simulations, and evaluated its efficiency in blocking MPAG hydrolysis in an Escherichia coli-based β-G activity assay. The pharmacological effect of amoxapine was evaluated in a mouse model. KEY FINDINGS We observed that MPA impairs intestinal epithelial cell homeostasis. Amoxapine efficiently blocks the hydrolysis of MPAG to MPA and significantly reduces digestive exposure to MPA in mice. As a result, administration of amoxapine in MPA-treated mice significantly attenuated gastrointestinal lesions. SIGNIFICANCE Collectively, these results suggest that the digestive accumulation of MPA is involved in the pathophysiology of MPA-gastrointestinal adverse effects. This study provides a proof-of-concept of the therapeutic potential of bacterial β-G inhibitors in glucuronidated drug-induced enteropathy.
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Affiliation(s)
- Clarisse Brossier
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Manon Jardou
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Angelika Janaszkiewicz
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Djouher Firoud
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Isy Petit
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Hélène Arnion
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Emilie Pinault
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - François-Ludovic Sauvage
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Anne Druilhe
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Nicolas Picard
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France; Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, F-87000 Limoges, France
| | - Florent Di Meo
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France
| | - Pierre Marquet
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France; Department of Pharmacology, Toxicology and Pharmacovigilance, CHU Limoges, F-87000 Limoges, France
| | - Roland Lawson
- Pharmacology & Transplantation (P&T), INSERM U1248, Université de Limoges, F-87000 Limoges, France.
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31
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Choi SR, Lee J, Seo YJ, Jin HS, Ahn HB, Go Y, Kim NK, Ryu KS, Lee JH. Molecular basis of facilitated target search and sequence discrimination of TALE homeodomain transcription factor Meis1. Nat Commun 2024; 15:6984. [PMID: 39143123 PMCID: PMC11325038 DOI: 10.1038/s41467-024-51297-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 08/05/2024] [Indexed: 08/16/2024] Open
Abstract
Transcription factors specifically bind to their consensus sequence motifs and regulate transcription efficiency. Transcription factors are also able to non-specifically contact the phosphate backbone of DNA through electrostatic interaction. The homeodomain of Meis1 TALE human transcription factor (Meis1-HD) recognizes its target DNA sequences via two DNA contact regions, the L1-α1 region and the α3 helix (specific binding mode). This study demonstrates that the non-specific binding mode of Meis1-HD is the energetically favored process during DNA binding, achieved by the interaction of the L1-α1 region with the phosphate backbone. An NMR dynamics study suggests that non-specific binding might set up an intermediate structure which can then rapidly and easily find the consensus region on a long section of genomic DNA in a facilitated binding process. Structural analysis using NMR and molecular dynamics shows that key structural distortions in the Meis1-HD-DNA complex are induced by various single nucleotide mutations in the consensus sequence, resulting in decreased DNA binding affinity. Collectively, our results elucidate the detailed molecular mechanism of how Meis1-HD recognizes single nucleotide mutations within its consensus sequence: (i) through the conformational features of the α3 helix; and (ii) by the dynamic features (rigid or flexible) of the L1 loop and the α3 helix. These findings enhance our understanding of how single nucleotide mutations in transcription factor consensus sequences lead to dysfunctional transcription and, ultimately, human disease.
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Affiliation(s)
- Seo-Ree Choi
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
- Advanced Analysis Data Center, Korea Institute of Science and Technology, Seoul, 02456, Republic of Korea
| | - Juyong Lee
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Pharmacy, Seoul National University, Seoul, 08826, Republic of Korea.
- Research Institute of Pharmaceutical Science, College of Pharmacy, Seoul National University, Seoul, 08826, Republic of Korea.
- Arontier Co., Seoul, 06735, Republic of Korea.
| | - Yeo-Jin Seo
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
| | - Ho-Seong Jin
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
| | - Hye-Bin Ahn
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
| | - Youyeon Go
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
| | - Nak-Kyoon Kim
- Advanced Analysis Data Center, Korea Institute of Science and Technology, Seoul, 02456, Republic of Korea
| | - Kyoung-Seok Ryu
- Protein Structure Research Team, Korea Basic Science Institute, Cheongju, Chungcheongbuk-do, 28119, Republic of Korea
| | - Joon-Hwa Lee
- Department of Chemistry and RINS, Gyeongsang National University, Jinju, Gyeongsangnam-do, 52828, Republic of Korea
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32
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Takaba K, Friedman AJ, Cavender CE, Behara PK, Pulido I, Henry MM, MacDermott-Opeskin H, Iacovella CR, Nagle AM, Payne AM, Shirts MR, Mobley DL, Chodera JD, Wang Y. Machine-learned molecular mechanics force fields from large-scale quantum chemical data. Chem Sci 2024; 15:12861-12878. [PMID: 39148808 PMCID: PMC11322960 DOI: 10.1039/d4sc00690a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 06/17/2024] [Indexed: 08/17/2024] Open
Abstract
The development of reliable and extensible molecular mechanics (MM) force fields-fast, empirical models characterizing the potential energy surface of molecular systems-is indispensable for biomolecular simulation and computer-aided drug design. Here, we introduce a generalized and extensible machine-learned MM force field, espaloma-0.3, and an end-to-end differentiable framework using graph neural networks to overcome the limitations of traditional rule-based methods. Trained in a single GPU-day to fit a large and diverse quantum chemical dataset of over 1.1 M energy and force calculations, espaloma-0.3 reproduces quantum chemical energetic properties of chemical domains highly relevant to drug discovery, including small molecules, peptides, and nucleic acids. Moreover, this force field maintains the quantum chemical energy-minimized geometries of small molecules and preserves the condensed phase properties of peptides and folded proteins, self-consistently parametrizing proteins and ligands to produce stable simulations leading to highly accurate predictions of binding free energies. This methodology demonstrates significant promise as a path forward for systematically building more accurate force fields that are easily extensible to new chemical domains of interest.
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Affiliation(s)
- Kenichiro Takaba
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
- Pharmaceuticals Research Center, Advanced Drug Discovery, Asahi Kasei Pharma Corporation Shizuoka 410-2321 Japan
| | - Anika J Friedman
- Department of Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80309 USA
| | - Chapin E Cavender
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego 9500 Gilman Drive La Jolla CA 92093 USA
| | - Pavan Kumar Behara
- Center for Neurotherapeutics, Department of Pathology and Laboratory Medicine, University of California Irvine CA 92697 USA
| | - Iván Pulido
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
| | - Michael M Henry
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
| | | | - Christopher R Iacovella
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
| | - Arnav M Nagle
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
- Department of Bioengineering, University of California, Berkeley Berkeley CA 94720 USA
| | - Alexander Matthew Payne
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
- Tri-Institutional PhD Program in Chemical Biology, Memorial Sloan Kettering Cancer Center New York 10065 USA
| | - Michael R Shirts
- Department of Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80309 USA
| | - David L Mobley
- Department of Pharmaceutical Sciences, University of California Irvine California 92697 USA
| | - John D Chodera
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
| | - Yuanqing Wang
- Simons Center for Computational Physical Chemistry and Center for Data Science, New York University New York NY 10004 USA
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center New York NY 10065 USA
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33
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Heinzelmann G, Huggins DJ, Gilson MK. BAT2: an Open-Source Tool for Flexible, Automated, and Low Cost Absolute Binding Free Energy Calculations. J Chem Theory Comput 2024; 20:6518-6530. [PMID: 39088306 PMCID: PMC11325538 DOI: 10.1021/acs.jctc.4c00205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
Absolute binding free energy (ABFE) calculations with all-atom molecular dynamics (MD) have the potential to greatly reduce costs in the first stages of drug discovery. Here, we introduce BAT2, the new version of the Binding Affinity Tool (BAT.py), designed to combine full automation of ABFE calculations with high-performance MD simulations, making it a potential tool for virtual screening. We describe and test several changes and new features that were incorporated into the code, such as relative restraints between the protein and the ligand instead of using fixed dummy atoms, support for the OpenMM simulation engine, a merged approach to the application/release of restraints, support for cobinders and proteins with multiple chains, and many others. We also reduced the simulation times for each ABFE calculation, assessing the effect on the expected robustness and accuracy of the calculations.
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Affiliation(s)
- Germano Heinzelmann
- Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis 88040-970, Brasil
| | - David J Huggins
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10065, United States
- Sanders Tri-Institutional Therapeutics Discovery Institute, 1230 York Avenue, Box 122, New York, New York 10065, United States
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego 92093, United States
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Li Z, Bhowmik S, Sagresti L, Brancato G, Smith M, Benson DE, Li P, Merz KM. Simulating Metal-Imidazole Complexes. J Chem Theory Comput 2024; 20:6706-6716. [PMID: 39081207 PMCID: PMC11325557 DOI: 10.1021/acs.jctc.4c00581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
One commonly observed binding motif in metalloproteins involves the interaction between a metal ion and histidine's imidazole side chains. Although previous imidazole-M(II) parameters established the flexibility and reliability of the 12-6-4 Lennard-Jones (LJ)-type nonbonded model by simply tuning the ligating atom's polarizability, they have not been applied to multiple-imidazole complexes. To fill this gap, we systematically simulate multiple-imidazole complexes (ranging from one to six) for five metal ions (Co(II), Cu(II), Mn(II), Ni(II), and Zn(II)) which commonly appear in metalloproteins. Using extensive (40 ns per PMF window) sampling to assemble free energy association profiles (using OPC water and standard HID imidazole charge models from AMBER) and comparing the equilibrium distances to DFT calculations, a new set of parameters was developed to focus on energetic and geometric features of multiple-imidazole complexes. The obtained free energy profiles agree with the experimental binding free energy and DFT calculated distances. To validate our model, we show that we can close the thermodynamic cycle for metal-imidazole complexes with up to six imidazole molecules in the first solvation shell. Given the success in closing the thermodynamic cycles, we then used the same extended sampling method for six other metal ions (Ag(I), Ca(II), Cd(II), Cu(I), Fe(II), and Mg(II)) to obtain new parameters. Since these new parameters can reproduce the one-imidazole geometry and energy accurately, we hypothesize that they will reasonably predict the binding free energy of higher-level coordination numbers. Hence, we did not extend the analysis of these ions up to six imidazole complexes. Overall, the results shed light on metal-protein interactions by emphasizing the importance of ligand-ligand interaction and metal-π-stacking within metalloproteins.
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Affiliation(s)
- Zhen Li
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Subhamoy Bhowmik
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Luca Sagresti
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
- CSGI, Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
- CSGI, Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
| | - Madelyn Smith
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - David E Benson
- Department of Chemistry & Biochemistry, Calvin University, Grand Rapids, Michigan 49546, United States
| | - Pengfei Li
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Kenneth M Merz
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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35
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Knappeová B, Mlýnský V, Pykal M, Šponer J, Banáš P, Otyepka M, Krepl M. Comprehensive Assessment of Force-Field Performance in Molecular Dynamics Simulations of DNA/RNA Hybrid Duplexes. J Chem Theory Comput 2024; 20:6917-6929. [PMID: 39012172 PMCID: PMC11325551 DOI: 10.1021/acs.jctc.4c00601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Mixed double helices formed by RNA and DNA strands, commonly referred to as hybrid duplexes or hybrids, are essential in biological processes like transcription and reverse transcription. They are also important for their applications in CRISPR gene editing and nanotechnology. Yet, despite their significance, the hybrid duplexes have been seldom modeled by atomistic molecular dynamics methodology, and there is no benchmark study systematically assessing the force-field performance. Here, we present an extensive benchmark study of polypurine tract (PPT) and Dickerson-Drew dodecamer hybrid duplexes using contemporary and commonly utilized pairwise additive and polarizable nucleic acid force fields. Our findings indicate that none of the available force-field choices accurately reproduces all the characteristic structural details of the hybrid duplexes. The AMBER force fields are unable to populate the C3'-endo (north) pucker of the DNA strand and underestimate inclination. The CHARMM force field accurately describes the C3'-endo pucker and inclination but shows base pair instability. The polarizable force fields struggle with accurately reproducing the helical parameters. Some force-field combinations even demonstrate a discernible conflict between the RNA and DNA parameters. In this work, we offer a candid assessment of the force-field performance for mixed DNA/RNA duplexes. We provide guidance on selecting utilizable force-field combinations and also highlight potential pitfalls and best practices for obtaining optimal performance.
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Affiliation(s)
- Barbora Knappeová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Martin Pykal
- Czech Advanced Technology and Research Institute, CATRIN, Palacký University, Křížkovského 511/8, Olomouc 779 00, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Pavel Banáš
- Czech Advanced Technology and Research Institute, CATRIN, Palacký University, Křížkovského 511/8, Olomouc 779 00, Czech Republic
| | - Michal Otyepka
- Czech Advanced Technology and Research Institute, CATRIN, Palacký University, Křížkovského 511/8, Olomouc 779 00, Czech Republic
- IT4Innovations, VSB-Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba 708 00, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
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36
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Yang D, Chong LT. WEDAP: A Python Package for Streamlined Plotting of Molecular Simulation Data. J Chem Inf Model 2024; 64:5749-5755. [PMID: 39013164 PMCID: PMC11323263 DOI: 10.1021/acs.jcim.4c00867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/01/2024] [Accepted: 07/06/2024] [Indexed: 07/18/2024]
Abstract
Given the growing interest in path sampling methods for extending the time scales of molecular dynamics (MD) simulations, there has been great interest in software tools that streamline the generation of plots for monitoring the progress of large-scale simulations. Here, we present the WEDAP Python package for simplifying the analysis of data generated from either conventional MD simulations or the weighted ensemble (WE) path sampling method, as implemented in the widely used WESTPA software package. WEDAP facilitates (i) the parsing of WE simulation data stored in highly compressed, hierarchical HDF5 files and (ii) incorporates trajectory weights from WE simulations into all generated plots. Our Python package consists of multiple user-friendly interfaces: a command-line interface, a graphical user interface, and a Python application programming interface. We demonstrate the plotting features of WEDAP through a series of examples using data from WE and conventional MD simulations that focus on the HIV-1 capsid protein's C-terminal domain dimer as a showcase system. The source code for WEDAP is freely available on GitHub at https://github.com/chonglab-pitt/wedap.
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Affiliation(s)
- Darian
T. Yang
- Molecular
Biophysics and Structural Biology Graduate Program, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania 15260, United States
- Department
of Structural Biology, University of Pittsburgh
School of Medicine, Pittsburgh, Pennsylvania 15260, United States
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Lillian T. Chong
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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37
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Mathez G, Brancale A, Cagno V. Novel Inhibitors of SARS-CoV-2 RNA Identified through Virtual Screening. J Chem Inf Model 2024; 64:6190-6196. [PMID: 39037082 PMCID: PMC11323243 DOI: 10.1021/acs.jcim.4c00758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 07/08/2024] [Accepted: 07/10/2024] [Indexed: 07/23/2024]
Abstract
We currently lack antivirals for most human viruses. In a quest for new molecules, focusing on viral RNA, instead of viral proteins, can represent a promising strategy. In this study, new inhibitors were identified starting from a published crystal structure of the tertiary SARS-CoV-2 RNA involved in the -1 programmed ribosomal frameshift. The pseudoknot structure was refined, and a virtual screening was performed using the repository of binders to the nucleic acid library, taking into consideration RNA flexibility. Hit compounds were validated against the wild-type virus and with a dual-luciferase assay measuring the frameshift efficiency. Several active molecules were identified. Our study reveals new inhibitors of SARS-CoV-2 but also highlights the feasibility of targeting RNA starting from virtual screening, a strategy that could be broadly applied to drug development.
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Affiliation(s)
- Gregory Mathez
- Institute
of Microbiology, University Hospital of
Lausanne, University of Lausanne, 1011 Lausanne, Switzerland
- Department
of Organic Chemistry, University of Chemistry
and Technology Prague, 16628 Prague 6, Czech Republic
| | - Andrea Brancale
- Department
of Organic Chemistry, University of Chemistry
and Technology Prague, 16628 Prague 6, Czech Republic
| | - Valeria Cagno
- Institute
of Microbiology, University Hospital of
Lausanne, University of Lausanne, 1011 Lausanne, Switzerland
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38
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Smirnov KS. Effects of Surface Charge Distribution and Electrolyte Ions on the Nonlinear Spectra of Model Solid-Water Interfaces. Molecules 2024; 29:3758. [PMID: 39202839 PMCID: PMC11356812 DOI: 10.3390/molecules29163758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/31/2024] [Accepted: 08/01/2024] [Indexed: 09/03/2024] Open
Abstract
Molecular dynamics simulations of model charged solid/water interfaces were carried out to provide insight about the relationship between the second-order nonlinear susceptibility χ(2) and the structure of the interfacial water layer. The results of the calculations reveal that the density fluctuations of water extend to about 12 Å from the surface regardless of the system, while the orientational ordering of molecules is long-ranged and is sensitive to the presence of electrolytes. The charge localization on the surface was found to affect only the high-frequency part of the Im[χ(2)] spectrum, and the addition of salt has very little effect on the spectrum of the first water layer. For solid/neat water interfaces, the spectroscopically active part of the liquid phase has a thickness largely exceeding the region of density fluctuations, and this long-ranged nonlinear activity is mediated by the electric field of the molecules. The electrolyte ions and their hydration shells act in a destructive way on the molecular field. This effect, combined with the screening of the surface charge by ions, drastically reduces the thickness of the spectroscopic diffuse layer. There is an electrolyte concentration at which the nonlinear response of the diffuse layer is suppressed and the χ(2) spectrum of the interface essentially coincides with that of the first water layer.
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Affiliation(s)
- Konstantin S Smirnov
- Univ. Lille, CNRS, UMR 8516 - LASIRe - Laboratoire Avancé de Spectroscopie pour les Interactions la Réactivité et l'Environnement, F-59000 Lille, France
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39
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Huang X, Chorianopoulou A, Kalkounou P, Georgiou M, Pousias A, Davies A, Pearce A, Harris M, Lambrinidis G, Marakos P, Pouli N, Kolocouris A, Lougiakis N, Ladds G. Hit-to-Lead Optimization of Heterocyclic Carbonyloxycarboximidamides as Selective Antagonists at Human Adenosine A3 Receptor. J Med Chem 2024; 67:13117-13146. [PMID: 39073853 PMCID: PMC11320584 DOI: 10.1021/acs.jmedchem.4c01092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/30/2024]
Abstract
Antagonism of the human adenosine A3 receptor (hA3R) has potential therapeutic application. Alchemical relative binding free energy calculations of K18 and K32 suggested that the combination of a 3-(2,6-dichlorophenyl)-isoxazolyl group with 2-pyridinyl at the ends of a carbonyloxycarboximidamide group should improve hA3R affinity. Of the 25 new analogues synthesized, 37 and 74 showed improved hA3R affinity compared to K18 (and K32). This was further improved through the addition of a bromine group to the 2-pyridinyl at the 5-position, generating compound 39. Alchemical relative binding free energy calculations, mutagenesis studies and MD simulations supported the compounds' binding pattern while suggesting that the bromine of 39 inserts deep into the hA3R orthosteric pocket, so highlighting the importance of rigidification of the carbonyloxycarboximidamide moiety. MD simulations highlighted the importance of rigidification of the carbonyloxycarboximidamide, while suggesting that the bromine of 39 inserts deep into the hA3R orthosteric pocket, which was supported through mutagenesis studies 39 also selectively antagonized endogenously expressed hA3R in nonsmall cell lung carcinoma cells, while pharmacokinetic studies indicated low toxicity enabling in vivo evaluation. We therefore suggest that 39 has potential for further development as a high-affinity hA3R antagonist.
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Affiliation(s)
- Xianglin Huang
- Department
of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K.
| | - Anna Chorianopoulou
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Panagoula Kalkounou
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Maria Georgiou
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Athanasios Pousias
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Amy Davies
- Department
of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K.
| | - Abigail Pearce
- Department
of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K.
| | - Matthew Harris
- Department
of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K.
| | - George Lambrinidis
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Panagiotis Marakos
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Nicole Pouli
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Antonios Kolocouris
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Nikolaos Lougiakis
- Laboratory
of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department
of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou 15771, Athens, Greece
| | - Graham Ladds
- Department
of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K.
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40
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Drosou M, Bhattacharjee S, Pantazis DA. Combined Multireference-Multiscale Approach to the Description of Photosynthetic Reaction Centers. J Chem Theory Comput 2024; 20. [PMID: 39116215 PMCID: PMC11360140 DOI: 10.1021/acs.jctc.4c00578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/02/2024] [Accepted: 07/12/2024] [Indexed: 08/10/2024]
Abstract
A first-principles description of the primary photochemical processes that drive photosynthesis and sustain life on our planet remains one of the grand challenges of modern science. Recent research established that explicit incorporation of protein electrostatics in excited-state calculations of photosynthetic pigments, achieved for example with quantum-mechanics/molecular-mechanics (QM/MM) approaches, is essential for a meaningful description of the properties and function of pigment-protein complexes. Although time-dependent density functional theory has been used productively so far in QM/MM approaches for the study of such systems, this methodology has limitations. Here we pursue for the first time a QM/MM description of the reaction center in the principal enzyme of oxygenic photosynthesis, Photosystem II, using multireference wave function theory for the high-level QM region. We identify best practices and establish guidelines regarding the rational choice of active space and appropriate state-averaging for the efficient and reliable use of complete active space self-consistent field (CASSCF) and the N-electron valence state perturbation theory (NEVPT2) in the prediction of low-lying excited states of chlorophyll and pheophytin pigments. Given that the Gouterman orbitals are inadequate as a minimal active space, we define specific minimal and extended active spaces for the NEVPT2 description of electronic states that fall within the Q and B bands. Subsequently, we apply our multireference-QM/MM protocol to the description of all pigments in the reaction center of Photosystem II. The calculations reproduce the electrochromic shifts induced by the protein matrix and the ordering of site energies consistent with the identity of the primary donor (ChlD1) and the experimentally known asymmetric and directional electron transfer. The optimized protocol sets the stage for future multireference treatments of multiple pigments, and hence for multireference studies of charge separation, while it is transferable to the study of any photoactive embedded tetrapyrrole system.
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Affiliation(s)
- Maria Drosou
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Sinjini Bhattacharjee
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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41
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Ukladov EO, Tyugashev TE, Kuznetsov NA. Computational Modeling Study of the Molecular Basis of dNTP Selectivity in Human Terminal Deoxynucleotidyltransferase. Biomolecules 2024; 14:961. [PMID: 39199349 PMCID: PMC11352444 DOI: 10.3390/biom14080961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Revised: 08/03/2024] [Accepted: 08/05/2024] [Indexed: 09/01/2024] Open
Abstract
Human terminal deoxynucleotidyl transferase (TdT) can catalyze template-independent DNA synthesis during the V(D)J recombination and DNA repair through nonhomologous end joining. The capacity for template-independent random addition of nucleotides to single-stranded DNA makes this polymerase useful in various molecular biological applications involving sequential stepwise synthesis of oligonucleotides using modified dNTP. Nonetheless, a serious limitation to the applications of this enzyme is strong selectivity of human TdT toward dNTPs in the order dGTP > dTTP ≈ dATP > dCTP. This study involved molecular dynamics to simulate a potential impact of amino acid substitutions on the enzyme's selectivity toward dNTPs. It was found that the formation of stable hydrogen bonds between a nitrogenous base and amino acid residues at positions 395 and 456 is crucial for the preferences for dNTPs. A set of single-substitution and double-substitution mutants at these positions was analyzed by molecular dynamics simulations. The data revealed two TdT mutants-containing either substitution D395N or substitutions D395N+E456N-that possess substantially equalized selectivity toward various dNTPs as compared to the wild-type enzyme. These results will enable rational design of TdT-like enzymes with equalized dNTP selectivity for biotechnological applications.
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Affiliation(s)
- Egor O. Ukladov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia; (E.O.U.); (T.E.T.)
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Timofey E. Tyugashev
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia; (E.O.U.); (T.E.T.)
| | - Nikita A. Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia; (E.O.U.); (T.E.T.)
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
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42
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Kumar N. Uranyl (UO 22+) structuring and dynamics at graphene/electrolyte interface. Phys Chem Chem Phys 2024; 26:20799-20806. [PMID: 38958742 DOI: 10.1039/d4cp02108h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
The physicochemical phenomena at the solid/electrolyte interfaces govern various industrial processes ranging from energy generation, storage, and catalysis to chemical separations and purification. Adsorption-based solid/liquid extraction methods are promising for the selective and rapid separation of nuclear (such as uranium) and other critical materials. In this study, we quantified the adsorption, complexation, and dynamics of UO22+ ions on the graphene surface in various electrolyte media (LiNO3, NaNO3 and CsNO3) using all-atom molecular dynamics simulations, in combination with network theory based subensemble analysis, enhanced sampling, and temporal analysis. We observe that the choice of background electrolyte impacts the propensity of UO22+ adsorption on the graphene surface, with LiNO3 being the most favorable at both low and high uranyl-nitrate concentrations. Even though UO22+ primarily retained its coordination with water and interacted via the outer-sphere mechanism with graphene, the interfacial segregation of NO3- increased the number of contact ion pairs (CIPs) between UO22+ and NO3- ions, and the residence times of UO22+ within the interfacial region. This study provides a fundamental understanding of the structure and dynamics of UO22+ on the solid surface necessary to design advanced adsorption-based separation methods for energy-relevant materials.
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Affiliation(s)
- Nitesh Kumar
- Department of Chemistry, Washington State University, Pullman, Washington 99163, USA.
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43
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Gibby WAT, Barabash ML, Khovanov IA, Luchinsky DG, McClintock PVE. Ionic Coulomb blockade controls the current in a short narrow carbon nanotube. J Chem Phys 2024; 161:054710. [PMID: 39092950 DOI: 10.1063/5.0210853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 07/11/2024] [Indexed: 08/04/2024] Open
Abstract
We use all-atom molecular dynamics simulations to investigate ionic conduction in a short, charged, single-wall carbon nanotube. They reveal ionic Coulomb blockade (ICB) oscillations in the current as a function of the fixed charge on the wall, and an associated occupancy staircase. Current peaks related to fluctuations around the 2 → 1 and 1 → 0 steps in occupancy are clearly resolved, in agreement with ICB theory. Current peaks were also observed at constant occupancy. These unpredicted secondary peaks are attributed to edge effects involving a remote knock-on mechanism; they are attenuated, or absent, for certain choices of model parameters. The key parameters of the system that underlie the current oscillations are estimated using ICB theory and the potential of the mean force. Future perspectives opened up by these observations are discussed.
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Affiliation(s)
- William A T Gibby
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Miraslau L Barabash
- Department of Chemical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Igor A Khovanov
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Dmitry G Luchinsky
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
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44
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Tanimoto S, Okumura H. Why Is Arginine the Only Amino Acid That Inhibits Polyglutamine Monomers from Taking on Toxic Conformations? ACS Chem Neurosci 2024; 15:2925-2935. [PMID: 39009034 PMCID: PMC11311134 DOI: 10.1021/acschemneuro.4c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/09/2024] [Accepted: 06/13/2024] [Indexed: 07/17/2024] Open
Abstract
Polyglutamine (polyQ) diseases are devastating neurodegenerative disorders characterized by abnormal expansion of glutamine repeats within specific proteins. The aggregation of polyQ proteins is a critical pathological hallmark of these diseases. Arginine was identified as a promising inhibitory compound because it prevents polyQ-protein monomers from forming intra- and intermolecular β-sheet structures and hinders polyQ proteins from aggregating to form oligomers. Such an aggregation inhibitory effect was not observed in other amino acids. However, the underlying molecular mechanism of the aggregation inhibition and the factors that differentiate arginine from other amino acids, in terms of the inhibition of the polyQ-protein aggregation, remain poorly understood. Here, we performed replica-permutation molecular dynamics simulations to elucidate the molecular mechanism by which arginine inhibits the formation of the intramolecular β-sheet structure of a polyQ monomer. We found that the intramolecular β-sheet structure with more than four β-bridges of the polyQ monomer with arginine is more unstable than without any ligand and with lysine. We also found that arginine has 1.6-2.1 times more contact with polyQ than lysine. In addition, we revealed that arginine forms more hydrogen bonds with the main chain of the polyQ monomer than lysine. More hydrogen bonds formed between arginine and polyQ inhibit polyQ from forming the long intramolecular β-sheet structure. It is known that intramolecular β-sheet structure enhances intermolecular β-sheet structure between proteins. These effects are thought to be the reason for the inhibition of polyQ aggregation. This study provides insights into the molecular events underlying arginine's inhibition of polyQ-protein aggregation.
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Affiliation(s)
- Shoichi Tanimoto
- Exploratory
Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki 444-8787, Aichi, Japan
| | - Hisashi Okumura
- Exploratory
Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki 444-8787, Aichi, Japan
- National
Institutes of Natural Sciences, Institute
for Molecular Science, Okazaki 444-8787, Aichi, Japan
- Graduate
Institute for Advanced Studies, SOKENDAI, Okazaki 444-8787, Aichi, Japan
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45
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Kalathingal M, Rhee YM. Thermodynamic consequences of stapling side-chains on a peptide ligand using a lactam-bridge: A theoretical study on anti-angiogenic peptides targeting VEGF. Proteins 2024; 92:959-974. [PMID: 38602129 DOI: 10.1002/prot.26692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/12/2024]
Abstract
Peptides are promising therapeutic agents for various biological targets due to their high efficacy and low toxicity, and the design of peptide ligands with high binding affinity to the target of interest is of utmost importance in peptide-based drug design. Introducing a conformational constraint to a flexible peptide ligand using a side-chain lactam-bridge is a convenient and efficient method to improve its binding affinity to the target. However, in general, such a small structural modification to a flexible ligand made with the intent of lowering the configurational entropic penalty for binding may have unintended consequences in different components of the binding enthalpy and entropy, including the configurational entropy component, which are still not clearly understood. Toward probing this, we examine different components of the binding enthalpy and entropy as well as the underlying structure and dynamics, for a side-chain lactam-bridged peptide inhibitor and its flexible analog forming complexes with vascular endothelial growth factor (VEGF), using all-atom molecular dynamics simulations. It is found that introducing a side-chain lactam-bridge constraint into the flexible peptide analog led to a gain in configurational entropy change but losses in solvation entropy, solute internal energy, and solvation energy changes upon binding, pinpointing the opportunities and challenges in drug design. The present study features an interplay between configurational and solvation entropy changes, as well as the one between binding enthalpy and entropy, in ligand-target binding upon imposing a conformational constraint into a flexible ligand.
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Affiliation(s)
- Mahroof Kalathingal
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Young Min Rhee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
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46
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Guseman AJ, González JJ, Yang D, Gronenborn AM. Cumulative asparagine to aspartate deamidation fails to perturb γD-crystallin structure and stability. Protein Sci 2024; 33:e5120. [PMID: 39022918 PMCID: PMC11255865 DOI: 10.1002/pro.5120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 06/05/2024] [Accepted: 07/07/2024] [Indexed: 07/20/2024]
Abstract
Deamidation frequently is invoked as an important driver of crystallin aggregation and cataract formation. Here, we characterized the structural and biophysical consequences of cumulative Asn to Asp changes in γD-crystallin. Using NMR spectroscopy, we demonstrate that N- or C-terminal domain-confined or fully Asn to Asp changed γD-crystallin exhibits essentially the same 1H-15N HSQC spectrum as the wild-type protein, implying that the overall structure is retained. Only a very small thermodynamic destabilization for the overall Asn to Asp γD-crystallin variants was noted by chaotropic unfolding, and assessment of the colloidal stability, by measuring diffusion interaction parameters, yielded no substantive differences in association propensities. Furthermore, using molecular dynamics simulations, no significant changes in dynamics for proteins with Asn to Asp or iso-Asp changes were detected. Our combined results demonstrate that substitution of all Asn by Asp residues, reflecting an extreme case of deamidation, did not affect the structure and biophysical properties of γD-crystallin. This suggests that these changes alone cannot be the major determinant in driving cataract formation.
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Affiliation(s)
- Alex J. Guseman
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Jeremy J. González
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Darian Yang
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Angela M. Gronenborn
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
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47
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Guarra F, Colombo G. Conformational Dynamics, Energetics, and the Divergent Evolution of Allosteric Regulation: The Case of the Yeast MAPK Family. Chembiochem 2024; 25:e202400175. [PMID: 38775368 DOI: 10.1002/cbic.202400175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/24/2024] [Indexed: 07/06/2024]
Abstract
Allosteric mechanisms provide finely-tuned control over signalling proteins. Proteins of the same family may share high sequence identity and structural similarity but show distinct traits of allosteric control and evolutionary divergent regulation. Revealing the determinants of such properties may be important to understand the molecular bases of different regulatory pathways. Herein, we investigate whether and how evolutionarily-divergent traits of allosteric regulation in homologous proteins can be decoded in terms of internal dynamics and interaction networks that support functionally oriented conformations. In this framework, we start from the comparative analysis of the dynamics and energetics of the yeast MAP Kinases (MAPKs) Fus3 and Kss1 in their native basins. Importantly, distinctive dynamic and energetic stabilization features emerge, which can be related to the two proteins' differential ability to be phosphorylated and engage with the allosteric activator Ste5. We then expanded our study to other evolutionarily-related MAPKs. We show that the dynamical and energetical traits defining the distinct regulatory profiles of Fus3 and Kss1 can be traced along their evolutionary tree. Overall, our approach is able to reconnect (latent) allostery with the principal elements of protein structural stabilization and dynamics, showing how allosteric regulation was encrypted in MAPKs structure well before Ste5 appearance.
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Affiliation(s)
- Federica Guarra
- Department of Chemistry, University of Pavia, Via Taramelli 12, 27100, Pavia, Italia
| | - Giorgio Colombo
- Department of Chemistry, University of Pavia, Via Taramelli 12, 27100, Pavia, Italia
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48
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Kuri PR, Goswami P. Reverse vaccinology-based multi-epitope vaccine design against Indian group A rotavirus targeting VP7, VP4, and VP6 proteins. Microb Pathog 2024; 193:106775. [PMID: 38960216 DOI: 10.1016/j.micpath.2024.106775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 06/25/2024] [Accepted: 06/30/2024] [Indexed: 07/05/2024]
Abstract
Rotavirus, a primary contributor to severe cases of infantile gastroenteritis on a global scale, results in significant morbidity and mortality in the under-five population, particularly in middle to low-income countries, including India. WHO-approved live-attenuated vaccines are linked to a heightened susceptibility to intussusception and exhibit low efficacy, primarily attributed to the high genetic diversity of rotavirus, varying over time and across different geographic regions. Herein, molecular data on Indian rotavirus A (RVA) has been reviewed through phylogenetic analysis, revealing G1P[8] to be the prevalent strain of RVA in India. The conserved capsid protein sequences of VP7, VP4 and VP6 were used to examine helper T lymphocyte, cytotoxic T lymphocyte and linear B-cell epitopes. Twenty epitopes were identified after evaluation of factors such as antigenicity, non-allergenicity, non-toxicity, and stability. These epitopes were then interconnected using suitable linkers and an N-terminal beta defensin adjuvant. The in silico designed vaccine exhibited structural stability and interactions with integrins (αvβ3 and αIIbβ3) and toll-like receptors (TLR2 and TLR4) indicated by docking and normal mode analyses. The immune simulation profile of the designed RVA multiepitope vaccine exhibited its potential to trigger humoral as well as cell-mediated immunity, indicating that it is a promising immunogen. These computational findings indicate potential efficacy of the designed vaccine against rotavirus infection.
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Affiliation(s)
- Pooja Rani Kuri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
| | - Pranab Goswami
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
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Mykuliak VV, Rahikainen R, Ball NJ, Bussi G, Goult BT, Hytönen VP. Molecular dynamics simulations reveal how vinculin refolds partially unfolded talin rod helices to stabilize them against mechanical force. PLoS Comput Biol 2024; 20:e1012341. [PMID: 39110765 PMCID: PMC11333002 DOI: 10.1371/journal.pcbi.1012341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 08/19/2024] [Accepted: 07/21/2024] [Indexed: 08/21/2024] Open
Abstract
Vinculin binds to specific sites of mechanically unfolded talin rod domains to reinforce the coupling of the cell's exterior to its force generation machinery. Force-dependent vinculin-talin complexation and dissociation was previously observed as contraction or extension of the unfolded talin domains respectively using magnetic tweezers. However, the structural mechanism underlying vinculin recognition of unfolded vinculin binding sites (VBSs) in talin remains unknown. Using molecular dynamics simulations, we demonstrate that a VBS dynamically refolds under force, and that vinculin can recognize and bind to partially unfolded VBS states. Vinculin binding enables refolding of the mechanically strained VBS and stabilizes its folded α-helical conformation, providing resistance against mechanical stress. Together, these results provide an understanding of a recognition mechanism of proteins unfolded by force and insight into the initial moments of how vinculin binds unfolded talin rod domains during the assembly of this mechanosensing meshwork.
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Affiliation(s)
- Vasyl V. Mykuliak
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Rolle Rahikainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Neil J. Ball
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, SISSA, Trieste, Italy
| | - Benjamin T. Goult
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Vesa P. Hytönen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
- Fimlab Laboratories, Tampere, Finland
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50
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Ha K, Mundt-Machado N, Bisignano P, Pinedo A, Raleigh DR, Loeb G, Reiter JF, Cao E, Delling M. Cilia-enriched oxysterol 7β,27-DHC is required for polycystin ion channel activation. Nat Commun 2024; 15:6468. [PMID: 39085216 PMCID: PMC11291729 DOI: 10.1038/s41467-024-50318-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 06/28/2024] [Indexed: 08/02/2024] Open
Abstract
Polycystin-1 (PC-1) and PC-2 form a heteromeric ion channel complex that is abundantly expressed in primary cilia of renal epithelial cells. This complex functions as a non-selective cation channel, and mutations within the polycystin complex cause autosomal dominant polycystic kidney disease (ADPKD). The spatial and temporal regulation of the polycystin complex within the ciliary membrane remains poorly understood. Using both whole-cell and ciliary patch-clamp recordings, we identify a cilia-enriched oxysterol, 7β,27-dihydroxycholesterol (DHC), that serves as a necessary activator of the polycystin complex. We further identify an oxysterol-binding pocket within PC-2 and showed that mutations within this binding pocket disrupt 7β,27-DHC-dependent polycystin activation. Pharmacologic and genetic inhibition of oxysterol synthesis reduces channel activity in primary cilia. In summary, our findings reveal a regulator of the polycystin complex. This oxysterol-binding pocket in PC-2 may provide a specific target for potential ADPKD therapeutics.
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Affiliation(s)
- Kodaji Ha
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
| | - Nadine Mundt-Machado
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
| | - Paola Bisignano
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Aide Pinedo
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
| | - David R Raleigh
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA, USA
| | - Gabriel Loeb
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Markus Delling
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA.
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