1
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Watanabe S, Noguchi T. Intermediate Formation via Proton Release during the Photoassembly of the Water-Oxidizing Mn 4CaO 5 Cluster in Photosystem II. J Phys Chem B 2024; 128:8145-8161. [PMID: 39148348 DOI: 10.1021/acs.jpcb.4c03768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
The early stages of the photoassembly of the water-oxidizing Mn4CaO5 cluster in spinach photosystem II (PSII) were monitored using rapid-scan time-resolved Fourier transform infrared (FTIR) spectroscopy. Carboxylate stretching and the amide I bands, which appeared upon the flash-induced oxidation of a Mn2+ ion, changed their features during the subsequent dark rearrangement process, indicating the relocation of the Mn3+ ion concomitant with protein conformational changes. Monitoring the isotope-edited FTIR signals of a Mes buffer estimated that nearly two protons are released upon the Mn2+ oxidation. Quantum chemical calculations for models of the Mn binding site suggested that the proton of a water ligand is transferred to D1-H332 through a hydrogen bond upon the Mn3+ formation and then released to the bulk as the Mn3+ shifts to bind to this histidine. Another Mn2+ ion may be inserted to form a binuclear Mn3+Mn2+ complex, whose structure was calculated to be stabilized by a μ-hydroxo bridge hydrogen-bonded with deprotonated D1-H337. Nearly one additional proton can thus be released from this histidine, assuming that it is mostly protonated before illumination. Alternatively, a proton could be released by further insertion of Ca2+, forming a Mn3+Mn2+Ca2+ complex with another hydroxo ligand connecting Ca2+ to the Mn3+Mn2+ complex.
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Affiliation(s)
- Shunya Watanabe
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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2
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Frey Y, Lungu C, Meyer F, Hauth F, Hahn D, Kersten C, Heller V, Franz-Wachtel M, Macek B, Barsukov I, Olayioye MA. Regulation of the DLC3 tumor suppressor by a novel phosphoswitch. iScience 2024; 27:110203. [PMID: 39021807 PMCID: PMC11253157 DOI: 10.1016/j.isci.2024.110203] [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: 10/17/2023] [Revised: 03/04/2024] [Accepted: 06/04/2024] [Indexed: 07/20/2024] Open
Abstract
Deleted in liver cancer 3 (DLC3) is a Rho GTPase-activating protein (RhoGAP) that plays a crucial role in maintaining adherens junction integrity and coordinating polarized vesicle transport by modulating Rho activity at the plasma membrane and endomembranes. By employing bioinformatical sequence analysis, in vitro experiments, and in cellulo assays we here identified a polybasic region (PBR) in DLC3 that facilitates the association of the protein with cellular membranes. Within the PBR, we mapped two serines whose phosphorylation can alter the electrostatic character of the region. Consequently, phosphomimetic mutations of these sites impaired the membrane association of DLC3. Furthermore, we found a new PBR-dependent localization of DLC3 at the midbody region, where the protein locally controlled Rho activity. Here, the phosphorylation-dependent regulation of DLC3 appeared to be required for proper cytokinesis. Our work thus provides a novel mechanism for spatiotemporal termination of Rho signaling by the RhoGAP protein DLC3.
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Affiliation(s)
- Yannick Frey
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
| | - Cristiana Lungu
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
- University of Stuttgart, Stuttgart Research Center Systems Biology, Stuttgart, Germany
| | - Florian Meyer
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
| | - Franziskus Hauth
- University of Liverpool, Institute of Systems, Molecular and Integrative Biology, Department of Biochemistry, Cell and Systems Biology, Liverpool, UK
| | - Daniel Hahn
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
| | - Corinna Kersten
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
| | - Vivien Heller
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
| | | | - Boris Macek
- Proteome Center Tübingen, University of Tübingen, Tübingen, Germany
| | - Igor Barsukov
- University of Liverpool, Institute of Systems, Molecular and Integrative Biology, Department of Biochemistry, Cell and Systems Biology, Liverpool, UK
| | - Monilola A. Olayioye
- University of Stuttgart, Institute of Cell Biology and Immunology, Stuttgart, Germany
- University of Stuttgart, Stuttgart Research Center Systems Biology, Stuttgart, Germany
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3
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Charlier C, Gavalda S, Grga J, Perrot L, Gabrielli V, Löhr F, Schörghuber J, Lichtenecker R, Arnal G, Marty A, Tournier V, Lippens G. Exploring the pH dependence of an improved PETase. Biophys J 2024; 123:1542-1552. [PMID: 38664965 PMCID: PMC11213969 DOI: 10.1016/j.bpj.2024.04.026] [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: 02/06/2024] [Revised: 03/20/2024] [Accepted: 04/23/2024] [Indexed: 05/12/2024] Open
Abstract
Enzymatic recycling of plastic and especially of polyethylene terephthalate (PET) has shown great potential to reduce its negative impact on our society. PET hydrolases (PETases) have been optimized using rational design and machine learning, but the mechanistic details of the PET depolymerization process remain unclear. Belonging to the carboxylic-ester hydrolase family with a canonical Ser-His-Asp catalytic triad, their observed alkaline pH optimum is generally thought to be related to the protonation state of the catalytic His. Here, we explore this aspect in the context of LCCICCG, an optimized PETase, derived from the leaf-branch compost cutinase enzyme. We use NMR to identify the dominant tautomeric structure of the six histidines. Five show surprisingly low pKa values below 4.0, whereas the catalytic H242 in the active enzyme displays a pKa value that varies from 4.9 to 4.7 when temperatures increase from 30°C to 50°C. Whereas the hydrolytic activity of the enzyme toward a soluble substrate can be modeled by the corresponding protonation/deprotonation curve, an important discrepancy is found when the substrate is the solid plastic. This opens the way to further mechanistic understanding of the PETase activity and underscores the importance of studying the enzyme at the liquid-solid interface.
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Affiliation(s)
- Cyril Charlier
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Sabine Gavalda
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | - Jelena Grga
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Laura Perrot
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Valeria Gabrielli
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Frank Löhr
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe, University Frankfurt, Frankfurt am Main, Germany
| | - Julia Schörghuber
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, Vienna, Austria
| | - Roman Lichtenecker
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, Vienna, Austria; MAG-LAB, Vienna, Austria
| | - Grégory Arnal
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | - Alain Marty
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | | | - Guy Lippens
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France.
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4
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Wu Z, Pope SD, Ahmed NS, Leung DL, Hajjar S, Yue Q, Anand DM, Kopp EB, Okin D, Ma W, Kagan JC, Hargreaves DC, Medzhitov R, Zhou X. Control of Inflammatory Response by Tissue Microenvironment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.592432. [PMID: 38798655 PMCID: PMC11118380 DOI: 10.1101/2024.05.10.592432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Inflammation is an essential defense response but operates at the cost of normal functions. Whether and how the negative impact of inflammation is monitored remains largely unknown. Acidification of the tissue microenvironment is associated with inflammation. Here we investigated whether macrophages sense tissue acidification to adjust inflammatory responses. We found that acidic pH restructured the inflammatory response of macrophages in a gene-specific manner. We identified mammalian BRD4 as a novel intracellular pH sensor. Acidic pH disrupts the transcription condensates containing BRD4 and MED1, via histidine-enriched intrinsically disordered regions. Crucially, decrease in macrophage intracellular pH is necessary and sufficient to regulate transcriptional condensates in vitro and in vivo, acting as negative feedback to regulate the inflammatory response. Collectively, these findings uncovered a pH-dependent switch in transcriptional condensates that enables environmental sensing to directly control inflammation, with a broader implication for calibrating the magnitude and quality of inflammation by the inflammatory cost.
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Affiliation(s)
- Zhongyang Wu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Scott D. Pope
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Nasiha S. Ahmed
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Diana L. Leung
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Stephanie Hajjar
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Qiuyu Yue
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing 100871, China
| | - Diya M. Anand
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Elizabeth B. Kopp
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Daniel Okin
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, Massachusetts, 02115
| | - Weiyi Ma
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jonathan C. Kagan
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Diana C. Hargreaves
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Ruslan Medzhitov
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Tananbaum Center for Theoretical and Analytical Human Biology, Yale University School of Medicine
| | - Xu Zhou
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
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5
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Ghosal M, Rakshit T, Bhattacharya S, Bhattacharyya S, Satpati P, Senapati D. E-Protein Protonation Titration-Induced Single-Particle Chemical Force Spectroscopy for Microscopic Understanding and pI Estimation of Infectious DENV. J Phys Chem B 2024; 128:3133-3144. [PMID: 38512319 DOI: 10.1021/acs.jpcb.4c00057] [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: 03/22/2024]
Abstract
The ionization state of amino acids on the outer surface of a virus regulates its physicochemical properties toward the sorbent surface. Serologically different strains of the dengue virus (DENV) show different extents of infectivity depending upon their interactions with a receptor on the host cell. To understand the structural dependence of E-protein protonation over its sequence dependence, we have followed E-protein titration kinetics both experimentally and theoretically for two differentially infected dengue serotypes, namely, DENV-2 and DENV-4. We have performed E-protein protonation titration-induced single-particle chemical force spectroscopy using an atomic force microscope (AFM) to measure the surface chemistry of DENV in physiological aqueous solutions not only to understand the charge distribution dynamics on the virus surface but also to estimate the isoelectric point (pI) accurately for infectious dengue viruses. Cryo-EM structure-based theoretical pI calculations of the DENV-2 surface protein were shown to be consistent with the evaluated pI value from force spectroscopy measurements. We also highlighted here the role of the microenvironment around the titrable residues (in the 3D-folded structure of the protein) in altering the pKa. This is a comprehensive study to understand how the cumulative charge distribution on the outer surface of a specific serotype of DENV regulates a prominent role of infectivity over minute changes at the genetic level.
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Affiliation(s)
- Manorama Ghosal
- Chemical Sciences Division, Saha Institute of Nuclear Physics (SINP), A CI of Homi Bhabha National Institute, 1/AF Bidhannagar, Kolkata, WB 700064, India
| | - Tatini Rakshit
- Department of Chemistry, School of Natural Sciences (SNS), Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, UP 201314, India
| | - Shreya Bhattacharya
- Computational Biology Lab, Department of Bioscience & Bioengineering, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India
| | - Sankar Bhattacharyya
- NCR Biotech Science Cluster, Translational Health Science and Technology Institute (THSTI), Faridabad-Gurugram Expressway, PO Box 4, Faridabad-Gurugram HR-121001, India
| | - Priyadarshi Satpati
- Computational Biology Lab, Department of Bioscience & Bioengineering, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India
| | - Dulal Senapati
- Chemical Sciences Division, Saha Institute of Nuclear Physics (SINP), A CI of Homi Bhabha National Institute, 1/AF Bidhannagar, Kolkata, WB 700064, India
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6
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Zaorska E, Malinska M. Cucurbit[7]uril-mediated Histidine Dimerization: Exploring the Structure and Binding Mechanism. Chemistry 2024; 30:e202302250. [PMID: 38055216 DOI: 10.1002/chem.202302250] [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: 07/14/2023] [Revised: 12/01/2023] [Accepted: 12/03/2023] [Indexed: 12/07/2023]
Abstract
Cucurbit[7,8]urils are known to form inclusion complexes with hydrophobic amino acids such as Trp, Tyr, Phe, and Met, as well as peptides containing these residues at the N-terminus. Despite their widespread use in protein purification, the affinity of histidine (His) for cucurbit[7,8]urils has not been extensively explored. In this study, X-ray diffraction experiments were conducted to investigate the binding of two histidine moieties to the cucurbit[7]uril (CB7) cavity, resulting in a network of π-π and hydrogen bonds. This assembly was found to induce a His pKa shift of ΔpKa=-4. Histidine weakly bound to CB7 or CB8; however, isothermal titration calorimetry revealed micromolar equilibrium dissociation constant values for CB7 and CB8 when bound to dipeptides containing His at the C-terminus. Conversely, dipeptides with His at the N-terminus exhibited millimolar values. Additionally, the His-Gly-Gly tripeptide formed a 2 : 1 complex with CB7. These findings suggest the potential use of histidine and histidine-containing tags in conjunction with CB7 for various biological applications.
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Affiliation(s)
- Ewelina Zaorska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - Maura Malinska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
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7
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Melchionna M, Ganusova EE, Harmon N, Alexandre G. TrhA, a bacterial progestin and adiponectin receptor homolog, couples membrane energetics homeostasis and unsaturated fatty acid metabolism. J Bacteriol 2024; 206:e0039723. [PMID: 38054739 PMCID: PMC10810207 DOI: 10.1128/jb.00397-23] [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: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 12/07/2023] Open
Abstract
Members of the widely conserved progestin and adipoQ receptor (PAQR) family function to maintain membrane homeostasis: membrane fluidity and fatty acid composition in eukaryotes and membrane energetics and fatty acid composition in bacteria. All PAQRs consist of a core seven transmembrane domain structure and five conserved amino acids (three histidines, one serine, and one aspartic acid) predicted to form a hydrolase-like catalytic site. PAQR homologs in Bacteria (called TrhA, for transmembrane homeostasis protein A) maintain homeostasis of membrane charge gradients, like the membrane potential and proton gradient that comprise the proton motive force, but their molecular mechanisms are not yet understood. Here, we show that TrhA in Escherichia coli has a periplasmic C-terminus, which places the five conserved residues shared by all PAQRs at the cytoplasmic interface of the membrane. Here, we characterize several conserved residues predicted to form an active site by site-directed mutagenesis. We also identify a specific role for TrhA in modulating unsaturated fatty acid biosynthesis with conserved residues required to either promote or reduce the abundance of unsaturated fatty acids. We also identify distinct roles for the conserved residues in supporting TrhA's role in maintaining membrane energetics homeostasis that suggest that both functions are intertwined and probably partly dependent on one another. An analysis of domain architecture of TrhA-like domains in Bacteria further supports a function of TrhA linking membrane energetics homeostasis with biosynthesis of unsaturated fatty acid in the membrane. IMPORTANCE Progestin and adipoQ receptor (PAQR) family proteins are evolutionary conserved regulators of membrane homeostasis and have been best characterized in eukaryotes. Bacterial PAQR homologs, named TrhA (transmembrane homeostasis protein A), regulate membrane energetics homeostasis through an unknown mechanism. Here, we present evidence linking TrhA to both membrane energetics homeostasis and unsaturated fatty acid biosynthesis. Analysis of domain architecture together with experimental evidence suggests a model where TrhA activity on unsaturated fatty acid biosynthesis is regulated by changes in membrane energetics to dynamically adjust membrane homeostasis.
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Affiliation(s)
- Maddison Melchionna
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Elena E. Ganusova
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Neyland Harmon
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Gladys Alexandre
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
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8
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Miyagi M, Nakazawa T. Significance of Histidine Hydrogen-Deuterium Exchange Mass Spectrometry in Protein Structural Biology. BIOLOGY 2024; 13:37. [PMID: 38248468 PMCID: PMC10813008 DOI: 10.3390/biology13010037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/04/2024] [Accepted: 01/06/2024] [Indexed: 01/23/2024]
Abstract
Histidine residues play crucial roles in shaping the function and structure of proteins due to their unique ability to act as both acids and bases. In other words, they can serve as proton donors and acceptors at physiological pH. This exceptional property is attributed to the side-chain imidazole ring of histidine residues. Consequently, determining the acid-base dissociation constant (Ka) of histidine imidazole rings in proteins often yields valuable insights into protein functions. Significant efforts have been dedicated to measuring the pKa values of histidine residues in various proteins, with nuclear magnetic resonance (NMR) spectroscopy being the most commonly used technique. However, NMR-based methods encounter challenges in assigning signals to individual imidazole rings and require a substantial amount of proteins. To address these issues associated with NMR-based approaches, a mass-spectrometry-based method known as histidine hydrogen-deuterium exchange mass spectrometry (His-HDX-MS) has been developed. This technique not only determines the pKa values of histidine imidazole groups but also quantifies their solvent accessibility. His-HDX-MS has proven effective across diverse proteins, showcasing its utility. This review aims to clarify the fundamental principles of His-HDX-MS, detail the experimental workflow, explain data analysis procedures and provide guidance for interpreting the obtained results.
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Affiliation(s)
- Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4988, USA
| | - Takashi Nakazawa
- Department of Chemistry, Nara Women’s University, Nara 630-8506, Japan
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9
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Heisler J, Kovner D, Izadi S, Zarzar J, Carter PJ. Modulation of the high concentration viscosity of IgG 1 antibodies using clinically validated Fc mutations. MAbs 2024; 16:2379560. [PMID: 39028186 PMCID: PMC11262234 DOI: 10.1080/19420862.2024.2379560] [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] [Accepted: 07/09/2024] [Indexed: 07/20/2024] Open
Abstract
The self-association of therapeutic antibodies can result in elevated viscosity and create problems in manufacturing and formulation, as well as limit delivery by subcutaneous injection. The high concentration viscosity of some antibodies has been reduced by variable domain mutations or by the addition of formulation excipients. In contrast, the impact of Fc mutations on antibody viscosity has been minimally explored. Here, we studied the effect of a panel of common and clinically validated Fc mutations on the viscosity of two closely related humanized IgG1, κ antibodies, omalizumab (anti-IgE) and trastuzumab (anti-HER2). Data presented here suggest that both Fab-Fab and Fab-Fc interactions contribute to the high viscosity of omalizumab, in a four-contact model of self-association. Most strikingly, the high viscosity of omalizumab (176 cP) was reduced 10.7- and 2.2-fold by Fc modifications for half-life extension (M252Y:S254T:T256E) and aglycosylation (N297G), respectively. Related single mutations (S254T and T256E) each reduced the viscosity of omalizumab by ~6-fold. An alternative half-life extension Fc mutant (M428L:N434S) had the opposite effect in increasing the viscosity of omalizumab by 1.5-fold. The low viscosity of trastuzumab (8.6 cP) was unchanged or increased by ≤ 2-fold by the different Fc variants. Molecular dynamics simulations provided mechanistic insight into the impact of Fc mutations in modulating electrostatic and hydrophobic surface properties as well as conformational stability of the Fc. This study demonstrates that high viscosity of some IgG1 antibodies can be mitigated by Fc mutations, and thereby offers an additional tool to help design future antibody therapeutics potentially suitable for subcutaneous delivery.
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Affiliation(s)
- Joel Heisler
- Department of Antibody Engineering, Genentech, Inc, South San Francisco, CA, USA
| | - Daniel Kovner
- Department of Pharmaceutical Development, Genentech, Inc, South San Francisco, CA, USA
| | - Saeed Izadi
- Department of Pharmaceutical Development, Genentech, Inc, South San Francisco, CA, USA
| | - Jonathan Zarzar
- Department of Pharmaceutical Development, Genentech, Inc, South San Francisco, CA, USA
| | - Paul J. Carter
- Department of Antibody Engineering, Genentech, Inc, South San Francisco, CA, USA
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10
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Pijning T, Vujičić‐Žagar A, van der Laan J, de Jong RM, Ramirez‐Palacios C, Vente A, Edens L, Dijkstra BW. Structural and time-resolved mechanistic investigations of protein hydrolysis by the acidic proline-specific endoprotease from Aspergillus niger. Protein Sci 2024; 33:e4856. [PMID: 38059672 PMCID: PMC10731622 DOI: 10.1002/pro.4856] [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: 06/14/2023] [Revised: 11/16/2023] [Accepted: 12/04/2023] [Indexed: 12/08/2023]
Abstract
Proline-specific endoproteases have been successfully used in, for example, the in-situ degradation of gluten, the hydrolysis of bitter peptides, the reduction of haze during beer production, and the generation of peptides for mass spectroscopy and proteomics applications. Here we present the crystal structure of the extracellular proline-specific endoprotease from Aspergillus niger (AnPEP), a member of the S28 peptidase family with rarely observed true proline-specific endoprotease activity. Family S28 proteases have a conventional Ser-Asp-His catalytic triad, but their oxyanion-stabilizing hole shows a glutamic acid, an amino acid not previously observed in this role. Since these enzymes have an acidic pH optimum, the presence of a glutamic acid in the oxyanion hole may confine their activity to an acidic pH. Yet, considering the presence of the conventional catalytic triad, it is remarkable that the A. niger enzyme remains active down to pH 1.5. The determination of the primary cleavage site of cytochrome c along with molecular dynamics-assisted docking studies indicate that the active site pocket of AnPEP can accommodate a reverse turn of approximately 12 amino acids with proline at the S1 specificity pocket. Comparison with the structures of two S28-proline-specific exopeptidases reveals not only a more spacious active site cavity but also the absence of any putative binding sites for amino- and carboxyl-terminal residues as observed in the exopeptidases, explaining AnPEP's observed endoprotease activity.
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Affiliation(s)
- Tjaard Pijning
- Biomolecular X‐ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Andreja Vujičić‐Žagar
- Biomolecular X‐ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | | | | | | | - Andre Vente
- Taste, Texture and HealthDSM‐FirmenichDelftThe Netherlands
| | - Luppo Edens
- Taste, Texture and HealthDSM‐FirmenichDelftThe Netherlands
| | - Bauke W. Dijkstra
- Biomolecular X‐ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
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11
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Solomon PE, Bracken CJ, Carozza JA, Wang H, Young EP, Wellner A, Liu CC, Sweet-Cordero EA, Li L, Wells JA. Discovery of VH domains that allosterically inhibit ENPP1. Nat Chem Biol 2024; 20:30-41. [PMID: 37400538 PMCID: PMC10746542 DOI: 10.1038/s41589-023-01368-5] [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: 02/05/2023] [Accepted: 05/23/2023] [Indexed: 07/05/2023]
Abstract
Ectodomain phosphatase/phosphodiesterase-1 (ENPP1) is overexpressed on cancer cells and functions as an innate immune checkpoint by hydrolyzing extracellular cyclic guanosine monophosphate adenosine monophosphate (cGAMP). Biologic inhibitors have not yet been reported and could have substantial therapeutic advantages over current small molecules because they can be recombinantly engineered into multifunctional formats and immunotherapies. Here we used phage and yeast display coupled with in cellulo evolution to generate variable heavy (VH) single-domain antibodies against ENPP1 and discovered a VH domain that allosterically inhibited the hydrolysis of cGAMP and adenosine triphosphate (ATP). We solved a 3.2 Å-resolution cryo-electron microscopy structure for the VH inhibitor complexed with ENPP1 that confirmed its new allosteric binding pose. Finally, we engineered the VH domain into multispecific formats and immunotherapies, including a bispecific fusion with an anti-PD-L1 checkpoint inhibitor that showed potent cellular activity.
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Affiliation(s)
- Paige E Solomon
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Colton J Bracken
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
- Cartography Biosciences, South San Francisco, CA, USA
| | - Jacqueline A Carozza
- Department of Biochemistry, Stanford University Medical School, Stanford, CA, USA
| | - Haoqing Wang
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
- Macromolecular Structural Knowledge Center, Stanford University, Stanford, CA, USA
| | - Elizabeth P Young
- Division of Pediatric Oncology, Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Alon Wellner
- Department of Biomedical Engineering, University of California, Irvine, CA, USA
| | - Chang C Liu
- Department of Biomedical Engineering, University of California, Irvine, CA, USA
- Department of Chemistry, University of California, Irvine, CA, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - E Alejandro Sweet-Cordero
- Division of Pediatric Oncology, Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Lingyin Li
- Department of Biochemistry, Stanford University Medical School, Stanford, CA, USA
| | - James A Wells
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA.
- Department of Cellular & Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA.
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12
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Augustine J, Baksh KA, Prosser RS, Zamble DB. Insights into the Allosteric Response to Acidity by the Helicobacter pylori NikR Transcription Factor. Biochemistry 2023; 62:3265-3275. [PMID: 37917856 DOI: 10.1021/acs.biochem.3c00356] [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: 11/04/2023]
Abstract
Helicobacter pylori NikR (HpNikR) is a nickel-responsive transcription factor that regulates genes involved in nickel homeostasis, which is essential for the survival of this pathogen within the acidic human stomach. HpNikR also responds to drops in pH and regulates genes controlling acid acclimation of the bacteria, independently of nickel. We previously showed that nickel binding biases the conformational ensemble of HpNikR to the more DNA-binding competent states via an allosteric network of residues encompassing the nickel binding sites and the interface between the metal- and DNA-binding domains. Here, we examine how acidity promotes this response using 19F-NMR, mutagenesis, and DNA-binding studies. 19F-NMR revealed that a drop in pH from 7.6 to 6.0 does little to shift the conformational ensemble of HpNikR to the DNA binding-compatible cis conformer. Nevertheless, DNA-binding affinities of apo-HpNikR at pH 6.0 and Ni(II)-HpNikR at pH 7.6 are comparable for the ureA promoter. Histidine residues of the nickel binding sites were shown to be important for pH-dependent DNA binding and thus likely impart positive charge to the protein, initiating long-range electrostatic interactions with DNA that induce DNA complexation. The results point to a different DNA-binding mechanism in response to acidity compared to the conformational selection mechanism in response to nickel and overall provide new insights into the influence of pH on HpNikR activity, which contributes to H. pylori viability.
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Affiliation(s)
- Jerry Augustine
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Karina A Baksh
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Robert Scott Prosser
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Deborah B Zamble
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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13
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Cvjetan N, Schuler LD, Ishikawa T, Walde P. Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate. ACS OMEGA 2023; 8:42878-42899. [PMID: 38024761 PMCID: PMC10652838 DOI: 10.1021/acsomega.3c05915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023]
Abstract
Iron porphyrins play several important roles in present-day living systems and probably already existed in very early life forms. Hemin (= ferric protoporphyrin IX = ferric heme b), for example, is the prosthetic group at the active site of heme peroxidases, catalyzing the oxidation of a number of different types of reducing substrates after hemin is first oxidized by hydrogen peroxide as the oxidizing substrate of the enzyme. The active site of heme peroxidases consists of a hydrophobic pocket in which hemin is embedded noncovalently and kept in place through coordination of the iron atom to a proximal histidine side chain of the protein. It is this partially hydrophobic local environment of the enzyme which determines the efficiency with which the sequential reactions of the oxidizing and reducing substrates proceed at the active site. Free hemin, which has been separated from the protein moiety of heme peroxidases, is known to aggregate in an aqueous solution and exhibits low catalytic activity. Based on previous reports on the use of surfactant micelles to solubilize free hemin in a nonaggregated state, the peroxidase-like activity of hemin in the presence of sodium dodecyl sulfate (SDS) at concentrations below and above the critical concentration for SDS micelle formation (critical micellization concentration (cmc)) was systematically investigated. In most experiments, 3,3',5,5'-tetramethylbenzidine (TMB) was applied as a reducing substrate at pH = 7.2. The presence of SDS clearly had a positive effect on the reaction in terms of initial reaction rate and reaction yield, even at concentrations below the cmc. The highest activity correlated with the cmc value, as demonstrated for reactions at three different HEPES concentrations. The 4-(2-hydroxyethyl)-1-piperazineethanesulfonate salt (HEPES) served as a pH buffer substance and also had an accelerating effect on the reaction. At the cmc, the addition of l-histidine (l-His) resulted in a further concentration-dependent increase in the peroxidase-like activity of hemin until a maximal effect was reached at an optimal l-His concentration, probably corresponding to an ideal mono-l-His ligation to hemin. Some of the results obtained can be understood on the basis of molecular dynamics simulations, which indicated the existence of intermolecular interactions between hemin and HEPES and between hemin and SDS. Preliminary experiments with SDS/dodecanol vesicles at pH = 7.2 showed that in the presence of the vesicles, hemin exhibited similar peroxidase-like activity as in the case of SDS micelles. This supports the hypothesis that micelle- or vesicle-associated ferric or ferrous iron porphyrins may have played a role as primitive catalysts in membranous prebiotic compartment systems before cellular life emerged.
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Affiliation(s)
- Nemanja Cvjetan
- Department
of Materials, ETH-Zürich, Leopold-Ruzicka-Weg 4, 8093 Zürich, Switzerland
| | | | - Takashi Ishikawa
- Department
of Biology and Chemistry, Paul Scherrer Institute and Department of
Biology, ETH-Zürich, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Peter Walde
- Department
of Materials, ETH-Zürich, Leopold-Ruzicka-Weg 4, 8093 Zürich, Switzerland
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14
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Michaelis M, Cupellini L, Mensch C, Perry CC, Delle Piane M, Colombi Ciacchi L. Tidying up the conformational ensemble of a disordered peptide by computational prediction of spectroscopic fingerprints. Chem Sci 2023; 14:8483-8496. [PMID: 37592980 PMCID: PMC10430726 DOI: 10.1039/d3sc02202a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/15/2023] [Indexed: 08/19/2023] Open
Abstract
The most advanced structure prediction methods are powerless in exploring the conformational ensemble of disordered peptides and proteins and for this reason the "protein folding problem" remains unsolved. We present a novel methodology that enables the accurate prediction of spectroscopic fingerprints (circular dichroism, infrared, Raman, and Raman optical activity), and by this allows for "tidying up" the conformational ensembles of disordered peptides and disordered regions in proteins. This concept is elaborated for and applied to a dodecapeptide, whose spectroscopic fingerprint is measured and theoretically predicted by means of enhanced-sampling molecular dynamics coupled with quantum mechanical calculations. Following this approach, we demonstrate that peptides lacking a clear propensity for ordered secondary-structure motifs are not randomly, but only conditionally disordered. This means that their conformational landscape, or phase-space, can be well represented by a basis-set of conformers including about 10 to 100 structures. The implications of this finding have profound consequences both for the interpretation of experimental electronic and vibrational spectral features of peptides in solution and for the theoretical prediction of these features using accurate and computationally expensive techniques. The here-derived methods and conclusions are expected to fundamentally impact the rationalization of so-far elusive structure-spectra relationships for disordered peptides and proteins, towards improved and versatile structure prediction methods.
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Affiliation(s)
- Monika Michaelis
- Hybrid Materials Interfaces Group, Faculty of Production Engineering, Bremen Center for Computational Materials Science, Center for Environmental Research and Sustainable Technology (UFT), and MAPEX Center for Materials and Processes, University of Bremen Am Fallturm 1 Bremen 28359 Germany
- Biomolecular and Materials Interface Research Group, Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University Clifton Lane Nottingham NG11 8NS UK
| | - Lorenzo Cupellini
- Dipartimento di Chimica e Chimica Industriale, University of Pisa Via G. Moruzzi 13 Pisa I-56124 Italy
| | - Carl Mensch
- Molecular Spectroscopy Research Group, Department of Chemistry, University of Antwerp Groenenborgerlaan 171 Antwerp 2020 Belgium
| | - Carole C Perry
- Biomolecular and Materials Interface Research Group, Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University Clifton Lane Nottingham NG11 8NS UK
| | - Massimo Delle Piane
- Hybrid Materials Interfaces Group, Faculty of Production Engineering, Bremen Center for Computational Materials Science, Center for Environmental Research and Sustainable Technology (UFT), and MAPEX Center for Materials and Processes, University of Bremen Am Fallturm 1 Bremen 28359 Germany
- Department of Applied Science and Technology, Politecnico di Torino Corso Duca degli Abruzzi 24 Torino 10129 Italy
| | - Lucio Colombi Ciacchi
- Hybrid Materials Interfaces Group, Faculty of Production Engineering, Bremen Center for Computational Materials Science, Center for Environmental Research and Sustainable Technology (UFT), and MAPEX Center for Materials and Processes, University of Bremen Am Fallturm 1 Bremen 28359 Germany
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15
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Lin M, Eubanks LM, Karadkhelkar NM, Blake S, Janda KD. Catalytic Antibody Blunts Carfentanil-Induced Respiratory Depression. ACS Pharmacol Transl Sci 2023; 6:802-811. [PMID: 37200811 PMCID: PMC10186356 DOI: 10.1021/acsptsci.3c00031] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Indexed: 05/20/2023]
Abstract
Carfentanil, the most potent of the fentanyl analogues, is at the forefront of synthetic opioid-related deaths, second to fentanyl. Moreover, the administration of the opioid receptor antagonist naloxone has proven inadequate for an increasing number of opioid-related conditions, often requiring higher/additional doses to be effective, as such interest in alternative strategies to combat more potent synthetic opioids has intensified. Increasing drug metabolism would be one strategy to detoxify carfentanil; however, carfentanil's major metabolic pathways involve N-dealkylation or monohydroxylation, which do not lend themselves readily to exogenous enzyme addition. Herein, we report, to our knowledge, the first demonstration that carfentanil's methyl ester when hydrolyzed to its acid was found to be 40,000 times less potent than carfentanil in activating the μ-opioid receptor. Physiological consequences of carfentanil and its acid were also examined through plethysmography, and carfentanil's acid was found to be incapable of inducing respiratory depression. Based upon this information, a hapten was chemically synthesized and immunized, allowing the generation of antibodies that were screened for carfentanil ester hydrolysis. From the screening campaign, three antibodies were found to accelerate the hydrolysis of carfentanil's methyl ester. From this series of catalytic antibodies, the most active underwent extensive kinetic analysis, allowing us to postulate its mechanism of hydrolysis against this synthetic opioid. In the context of potential clinical applications, the antibody, when passively administered, was able to reduce respiratory depression induced by carfentanil. The data presented supports further development of antibody catalysis as a biologic strategy to complement carfentanil overdose reversal.
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Affiliation(s)
- Mingliang Lin
- Departments of Chemistry
and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute
of Research and Medicine (WIRM), The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Lisa M. Eubanks
- Departments of Chemistry
and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute
of Research and Medicine (WIRM), The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Nishant M. Karadkhelkar
- Departments of Chemistry
and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute
of Research and Medicine (WIRM), The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Steven Blake
- Departments of Chemistry
and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute
of Research and Medicine (WIRM), The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Kim D. Janda
- Departments of Chemistry
and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute
of Research and Medicine (WIRM), The Scripps
Research Institute, La Jolla, California 92037, United States
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16
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Gao S, Campbell JX, Oas TG, Franz KJ. Multiple Modes of Zinc Binding to Histatin 5 Revealed by Buffer-Independent Thermodynamics. Inorg Chem 2023; 62:7087-7096. [PMID: 37083393 DOI: 10.1021/acs.inorgchem.3c00608] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Histatin 5 (Hist5) is an antimicrobial peptide found in human saliva as part of the innate immune system. Hist5 can bind several metal ions in vitro, and Zn2+ has been shown to function as an inhibitory switch to regulate the peptide's biological activity against the opportunistic fungal pathogen Candida albicans in cell culture. Here, we studied Zn2+ binding to Hist5 at four temperatures from 15 to 37 °C using isothermal titration calorimetry to obtain thermodynamic parameters that were corrected for competing buffer effects. Hist5 bound Zn2+ with a buffer-dependent association constant of ∼105 M-1 and a buffer-independent association constant of ∼6 × 106 M-1 at pH 7.4 and at all temperatures tested. Zn2+ binding was both enthalpically and entropically favorable, with larger entropic contributions at 15 °C and larger enthalpic contributions at 37 °C. Additionally, the Zn:Hist5 binding stoichiometry increased from 1:1 to 2:1 as temperature increased. The enthalpy-entropy compensation and the variable stoichiometry lead us to propose a model in which the Zn-Hist5 complex exists in an equilibrium between two distinct binding modes with different Zn:Hist5 stoichiometries. The in-depth thermodynamic analysis presented herein may help illuminate the biophysical basis for Zn-dependent changes in the antifungal activity of Hist5.
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Affiliation(s)
- Sean Gao
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Joanna X Campbell
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Terrence G Oas
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Katherine J Franz
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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17
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Rembert KB, Zhang J, Lee YJ. Effects of Salts and Surface Charge on the Biophysical Stability of a Low pI Monoclonal Antibody. J Pharm Sci 2023; 112:947-953. [PMID: 36395898 DOI: 10.1016/j.xphs.2022.11.010] [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: 09/09/2022] [Revised: 11/08/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022]
Abstract
The impact of five representative Hofmeister salts (NaCl, KCl, MgCl2, Na2SO4, and NaSCN) on the thermal stability and aggregation kinetics of a slightly acidic monoclonal antibody (mAb) were investigated under different pH conditions. The thermal stability of the mAb was assessed by measuring the lowest unfolding transition temperature, Tm, with differential scanning fluorimetry. MgCl2 and NaSCN significantly decreased Tm at all three charged states of the mAb, but to the greatest extent when the mAb surface charge was net positive. Non-native aggregation kinetics was monitored by measuring Rayleigh light scattering. When the mAb surface charge was net positive or net neutral, the nucleation rate increased non-monotonically with MgCl2 and NaSCN but decreased monotonically with NaCl, KCl, and Na2SO4. By contrast, when the mAb surface was negatively charged, there were only minor changes in the nucleation rate with all salts tested. Furthermore, there was less structural perturbation and slower aggregation rates when the mAb was net negatively charged than when it was net neutrally or positively charged. The observed salt effects on thermal unfolding are consistent with ion-specific mechanisms dominated by short-range amide backbone binding. On the other hand, the salt effects on nucleation rates appear to be influenced by both amide backbone binding and long-range electrostatic binding of ions to charged amino acid side chains.
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Affiliation(s)
- Kelvin B Rembert
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States
| | - Jifeng Zhang
- Department of Drug Delivery and Device Development, Medimmune-AstraZeneca, Gaithersburg, MD 20878, United States.
| | - Young Jong Lee
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States.
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18
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Alsaeedi M, Alghamdi H, Hayes P, Hogan AM, Gilchrist ES, Dowling KG, English JA, Glennon JD. Evaluation of hydrophilic interaction chromatography versus reversed-phase chromatography for fast aqueous species distribution analysis of Nickel(II)-Histidine complex species. J Chromatogr A 2023; 1693:463857. [PMID: 36812776 DOI: 10.1016/j.chroma.2023.463857] [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: 07/20/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023]
Abstract
Nickel (Ni) is a trace heavy metal of importance in biological and environmental systems, with well documented allergy and carcinogenic effects in humans. With Ni(II) as the dominant oxidation state, the elucidation of the coordination mechanisms and labile complex species responsible for its transportation, toxicity, allergy, and bioavailability is key to understanding its biological effects and location in living systems. Histidine (His) is an essential amino acid that contributes to protein structure and activity and in the coordination of Cu(II) and Ni(II) ions. The aqueous low molecular weight Ni(II)-Histidine complex consists primarily of two stepwise complex species Ni(II)(His)1 and Ni(II)(His)2 in the pH range of 4 to 12. Four chromatographic columns, including the superficially porous Poro-shell EC-C18, Halo RP-amide and Poro-shell bare silica-HILIC columns, alongside a Zic-cHILIC fully porous column, were evaluated for the fast separation of the individual Ni(II)-Histidine species. Of these the Zic-cHILIC exhibited high efficiency and selectivity to distinguish between the two stepwise species Ni(II)His1 and Ni(II)His2 as well as free Histidine, with a fast separation within 120 s at a flow rate of 1 ml/min. This HILIC method utilizing the Zic-cHILIC column was initially optimized for the simultaneous analysis of Ni(II)-His-species using UV detection with a mobile phase consisting of 70% ACN and sodium acetate buffer at wwpH 6. Furthermore, the aqueous metal complex species distribution analysis for the low molecular weight Ni(II)-histidine system was chromatographically determined at various metal-ligand ratios and as a function of pH. The identities of Ni(II)His1 and Ni(II)-His2 species were confirmed using HILIC electrospray ionization- mass spectrometry (HILIC-ESI-MS) at negative mode.
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Affiliation(s)
- Majidah Alsaeedi
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Huda Alghamdi
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Phyllis Hayes
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Anna M Hogan
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Elizabeth S Gilchrist
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland
| | - Kirsten G Dowling
- Department of Anatomy & Neuroscience, Paediatric Academic Unit, University College Cork and INFANT Centre, Cork University Hospital, Western Gateway Building, Cork, Ireland
| | - Jane A English
- Department of Anatomy & Neuroscience, Paediatric Academic Unit, University College Cork and INFANT Centre, Cork University Hospital, Western Gateway Building, Cork, Ireland
| | - Jeremy D Glennon
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), School of Chemistry, and the Analytical & Biological Chemistry Research Facility (ABCRF), University College Cork, Western Road, Cork T12 YN60, Ireland.
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19
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Structural Insight into Catalysis by the Flavin-Dependent NADH Oxidase (Pden_5119) of Paracoccus denitrificans. Int J Mol Sci 2023; 24:ijms24043732. [PMID: 36835143 PMCID: PMC9963409 DOI: 10.3390/ijms24043732] [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: 12/22/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023] Open
Abstract
The Pden_5119 protein oxidizes NADH with oxygen under mediation by the bound flavin mononucleotide (FMN) and may be involved in the maintenance of the cellular redox pool. In biochemical characterization, the curve of the pH-rate dependence was bell-shaped with pKa1 = 6.6 and pKa2 = 9.2 at 2 μM FMN while it contained only a descending limb pKa of 9.7 at 50 μM FMN. The enzyme was found to undergo inactivation by reagents reactive with histidine, lysine, tyrosine, and arginine. In the first three cases, FMN exerted a protective effect against the inactivation. X-ray structural analysis coupled with site-directed mutagenesis identified three amino acid residues important to the catalysis. Structural and kinetic data suggest that His-117 plays a role in the binding and positioning of the isoalloxazine ring of FMN, Lys-82 fixes the nicotinamide ring of NADH to support the proS-hydride transfer, and Arg-116 with its positive charge promotes the reaction between dioxygen and reduced flavin.
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20
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Wehrhan L, Leppkes J, Dimos N, Loll B, Koksch B, Keller BG. Water Network in the Binding Pocket of Fluorinated BPTI-Trypsin Complexes─Insights from Simulation and Experiment. J Phys Chem B 2022; 126:9985-9999. [PMID: 36409613 DOI: 10.1021/acs.jpcb.2c05496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Structural waters in the S1 binding pocket of β-trypsin are critical for the stabilization of the complex of β-trypsin with its inhibitor bovine pancreatic trypsin inhibitor (BPTI). The inhibitor strength of BPTI can be modulated by replacing the critical lysine residue at the P1 position by non-natural amino acids. We study BPTI variants in which the critical Lys15 in BPTI has been replaced by α-aminobutyric acid (Abu) and its fluorinated derivatives monofluoroethylglycine (MfeGly), difluoroethylglycine (DfeGly), and trifluoroethylglycine (TfeGly). We investigate the hypothesis that additional water molecules in the binding pocket can form specific noncovalent interactions with the fluorinated side chains and thereby act as an extension of the inhibitors. We report potentials of mean force (PMF) of the unbinding process for all four complexes and enzyme activity inhibition assays. Additionally, we report the protein crystal structure of the Lys15MfeGly-BPTI-β-trypsin complex (pdb: 7PH1). Both experimental and computational data show a stepwise increase in inhibitor strength with increasing fluorination of the Abu side chain. The PMF additionally shows a minimum for the encounter complex and an intermediate state just before the bound state. In the bound state, the computational analysis of the structure and dynamics of the water molecules in the S1 pocket shows a highly dynamic network of water molecules that does not indicate a rigidification or stabilizing trend in regard to energetic properties that could explain the increase in inhibitor strength. The analysis of the energy and the entropy of the water molecules in the S1 binding pocket using grid inhomogeneous solvation theory confirms this result. Overall, fluorination systematically changes the binding affinity, but the effect cannot be explained by a persistent water network in the binding pocket. Other effects, such as the hydrophobicity of fluorinated amino acids and the stability of the encounter complex as well as the additional minimum in the potential of mean force in the bound state, likely influence the affinity more directly.
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Affiliation(s)
- Leon Wehrhan
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, Berlin14195, Germany
| | - Jakob Leppkes
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 20, Berlin14195, Germany
| | - Nicole Dimos
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 6, Berlin14195, Germany
| | - Bernhard Loll
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 6, Berlin14195, Germany
| | - Beate Koksch
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 20, Berlin14195, Germany
| | - Bettina G Keller
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, Berlin14195, Germany
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21
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Pohl C, Effantin G, Kandiah E, Meier S, Zeng G, Streicher W, Segura DR, Mygind PH, Sandvang D, Nielsen LA, Peters GHJ, Schoehn G, Mueller-Dieckmann C, Noergaard A, Harris P. pH- and concentration-dependent supramolecular assembly of a fungal defensin plectasin variant into helical non-amyloid fibrils. Nat Commun 2022; 13:3162. [PMID: 35672293 PMCID: PMC9174238 DOI: 10.1038/s41467-022-30462-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Self-assembly and fibril formation play important roles in protein behaviour. Amyloid fibril formation is well-studied due to its role in neurodegenerative diseases and characterized by refolding of the protein into predominantly β-sheet form. However, much less is known about the assembly of proteins into other types of supramolecular structures. Using cryo-electron microscopy at a resolution of 1.97 Å, we show that a triple-mutant of the anti-microbial peptide plectasin, PPI42, assembles into helical non-amyloid fibrils. The in vitro anti-microbial activity was determined and shown to be enhanced compared to the wildtype. Plectasin contains a cysteine-stabilised α-helix-β-sheet structure, which remains intact upon fibril formation. Two protofilaments form a right-handed protein fibril. The fibril formation is reversible and follows sigmoidal kinetics with a pH- and concentration dependent equilibrium between soluble monomer and protein fibril. This high-resolution structure reveals that α/β proteins can natively assemble into fibrils. Here the authors report the cryo-EM structure of a triple-mutant of the anti-microbial peptide plectasin, PPI42, assembling in a pH- and concentration dependent manner into helical non-amyloid fibrils. The fibrils formation is reversible, and follows a sigmoidal kinetics. The fibrils adopt a right-handed helical superstructure composed by two protofilaments, stabilized by an outer hydrophobic ring and an inner hydrophobic centre. These findings reveal that α/β proteins can natively assemble into fibrils.
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22
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Glise L, Rutberg M, Håversen L, Levin MC, Levin M, Jeppsson A, Borén J, Fogelstrand P. pH-Dependent Protonation of Histidine Residues Is Critical for Electrostatic LDL (Low-Density Lipoprotein) Binding to Human Coronary Arteries. Arterioscler Thromb Vasc Biol 2022; 42:1037-1047. [PMID: 35652335 DOI: 10.1161/atvbaha.122.317868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The initiating step in atherogenesis is the electrostatic binding of LDL (low-density lipoprotein) to proteoglycan glycosaminoglycans in the arterial intima. However, although proteoglycans are widespread throughout the intima of most coronary artery segments, LDL is not evenly distributed, indicating that LDL retention is not merely dependent on the presence of proteoglycans. We aim to identify factors that promote the interaction between LDL and the vessel wall of human coronary arteries. METHODS We developed an ex vivo model to investigate binding of human-labeled LDL to human coronary artery sections without the interference of cellular processes. RESULTS By staining consecutive sections of human coronary arteries, we found strong staining of sulfated glycosaminoglycans throughout the arterial intima, whereas endogenous LDL deposits were focally distributed. Ex vivo binding of LDL was uniform in all intimal areas with sulfated glycosaminoglycans. However, lowering the pH from 7.4 to 6.5 triggered a 35-fold increase in LDL binding. The pH-dependent binding was abolished by pretreating LDL with diethyl-pyrocarbonate, which blocks the protonation of histidine residues, or cyclohexanedione, which inhibits the positive charge of site B on LDL. Thus, both histidine protonation and site B are required for strong electrostatic LDL binding to the intima. CONCLUSIONS This study identifies histidine protonation as an important component for electrostatic LDL binding to human coronary arteries. Our findings show that the local pH will have a profound impact on LDL's affinity for sulfated glycosaminoglycans, which may influence the retention and accumulation pattern of LDL in the arterial vasculature.
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Affiliation(s)
- Lars Glise
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
| | - Mikael Rutberg
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
| | - Liliana Håversen
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
| | - Malin C Levin
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
| | - Max Levin
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
| | - Anders Jeppsson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.).,Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden (A.J.)
| | - Jan Borén
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.).,Sahlgrenska University Hospital/Wallenberg Laboratory, Gothenburg, Sweden (J.B.)
| | - Per Fogelstrand
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Sweden (L.G., M.R., L.H., M.C.L., M.L., A.J., J.B., P.F.)
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23
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Lubner CE, Artz JH, Mulder DW, Oza A, Ward RJ, Williams SG, Jones AK, Peters JW, Smalyukh II, Bharadwaj VS, King PW. A site-differentiated [4Fe-4S] cluster controls electron transfer reactivity of Clostridium acetobutylicum [FeFe]-hydrogenase I. Chem Sci 2022; 13:4581-4588. [PMID: 35656134 PMCID: PMC9019909 DOI: 10.1039/d1sc07120c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/24/2022] [Indexed: 01/11/2023] Open
Abstract
One of the many functions of reduction–oxidation (redox) cofactors is to mediate electron transfer in biological enzymes catalyzing redox-based chemical transformation reactions. There are numerous examples of enzymes that utilize redox cofactors to form electron transfer relays to connect catalytic sites to external electron donors and acceptors. The compositions of relays are diverse and tune transfer thermodynamics and kinetics towards the chemical reactivity of the enzyme. Diversity in relay design is exemplified among different members of hydrogenases, enzymes which catalyze reversible H2 activation, which also couple to diverse types of donor and acceptor molecules. The [FeFe]-hydrogenase I from Clostridium acetobutylicum (CaI) is a member of a large family of structurally related enzymes where interfacial electron transfer is mediated by a terminal, non-canonical, His-coordinated, [4Fe–4S] cluster. The function of His coordination was examined by comparing the biophysical properties and reactivity to a Cys substituted variant of CaI. This demonstrated that His coordination strongly affected the distal [4Fe–4S] cluster spin state, spin pairing, and spatial orientations of molecular orbitals, with a minor effect on reduction potential. The deviations in these properties by substituting His for Cys in CaI, correlated with pronounced changes in electron transfer and reactivity with the native electron donor–acceptor ferredoxin. The results demonstrate that differential coordination of the surface localized [4Fe–4S]His cluster in CaI is utilized to control intermolecular and intramolecular electron transfer where His coordination creates a physical and electronic environment that enables facile electron exchange between electron carrier molecules and the iron–sulfur cluster relay for coupling to reversible H2 activation at the catalytic site. Histidine coordination of the distal [4Fe–4S] cluster in [FeFe]-hydrogenase was demonstrated to tune the cluster spin-states, spin-pairing and surrounding molecular orbitals to enable more facile electron transfer compared to cysteine coordination.![]()
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Affiliation(s)
| | - Jacob H Artz
- National Renewable Energy Laboratory Golden Colorado USA
| | - David W Mulder
- National Renewable Energy Laboratory Golden Colorado USA
| | - Aisha Oza
- National Renewable Energy Laboratory Golden Colorado USA
| | - Rachel J Ward
- Department of Physics, University of Colorado Boulder Boulder Colorado USA
| | - S Garrett Williams
- School of Molecular Sciences, Arizona State University Tempe Arizona USA.,Sandia National Laboratories Albuquerque New Mexico USA
| | - Anne K Jones
- School of Molecular Sciences, Arizona State University Tempe Arizona USA
| | - John W Peters
- Institute of Biological Chemistry, Washington State University Pullman Washington USA
| | - Ivan I Smalyukh
- Department of Physics, University of Colorado Boulder Boulder Colorado USA.,Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado Boulder Boulder Colorado USA
| | | | - Paul W King
- National Renewable Energy Laboratory Golden Colorado USA .,Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado Boulder Boulder Colorado USA
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24
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Lee PS, MacDonald KG, Massi E, Chew PV, Bee C, Perkins P, Chau B, Thudium K, Lohre J, Nandi P, Deyanova EG, Barman I, Gudmundsson O, Dollinger G, Sproul T, Engelhardt JJ, Strop P, Rajpal A. Improved therapeutic index of an acidic pH-selective antibody. MAbs 2022; 14:2024642. [PMID: 35192429 PMCID: PMC8865267 DOI: 10.1080/19420862.2021.2024642] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although therapeutically efficacious, ipilimumab can exhibit dose-limiting toxicity that prevents maximal efficacious clinical outcomes and can lead to discontinuation of treatment. We hypothesized that an acidic pH-selective ipilimumab (pH Ipi), which preferentially and reversibly targets the acidic tumor microenvironment over the neutral periphery, may have a more favorable therapeutic index. While ipilimumab has pH-independent CTLA-4 affinity, pH Ipi variants have been engineered to have up to 50-fold enhanced affinity to CTLA-4 at pH 6.0 compared to pH 7.4. In hCTLA-4 knock-in mice, these variants have maintained anti-tumor activity and reduced peripheral activation, a surrogate marker for toxicity. pH-sensitive therapeutic antibodies may be a differentiating paradigm and a novel modality for enhanced tumor targeting and improved safety profiles.
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Affiliation(s)
- Peter S Lee
- Discovery Biotherapeutics, Bristol Myers Squibb, Redwood City, CA, USA
| | | | - Evan Massi
- Immuno-Oncology Research, Bristol Myers Squibb, Redwood City, CA, USA
| | - Pamela V Chew
- Oncology Biology, Gilead Sciences, Foster City, CA, USA
| | - Christine Bee
- Discovery Biology, Frontier Medicines, South San Francisco, CA, USA
| | - Padma Perkins
- Immuno-Oncology Research, Bristol Myers Squibb, Redwood City, CA, USA
| | - Bryant Chau
- Kyverna, Synthetic Biology, Emeryville, CA, USA
| | - Kent Thudium
- Immuno-Oncology Research, Bristol Myers Squibb, Redwood City, CA, USA
| | - Jack Lohre
- In Vivo Pharmacology, Bristol Myers Squibb, Redwood City, CA, USA
| | - Pradyot Nandi
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Lawrenceville, NJ, USA
| | - Ekaterina G Deyanova
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Lawrenceville, NJ, USA
| | - Ishita Barman
- Therapeutic Discovery, 3T Biosciences, South San Francisco, CA, USA
| | - Olafur Gudmundsson
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Lawrenceville, NJ, USA
| | - Gavin Dollinger
- Discovery Biotherapeutics, Bristol Myers Squibb, Redwood City, CA, USA
| | - Tim Sproul
- In Vivo Pharmacology, UNITY Biotechnology, South San Francisco, CA, USA
| | | | - Pavel Strop
- Biologics Discovery, Tallac Therapeutics, Burlingame, CA, USA
| | - Arvind Rajpal
- Large Molecule Drug Discovery, Genentech Research and Early Development, South San Francisco, CA, USA
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25
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Liu C, Steer DL, Song H, He L. Superior Binding of Proteins on a Silica Surface: Physical Insight into the Synergetic Contribution of Polyhistidine and a Silica-Binding Peptide. J Phys Chem Lett 2022; 13:1609-1616. [PMID: 35142521 DOI: 10.1021/acs.jpclett.1c03306] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Controllable protein attachment onto solid interfaces is essential for the functionality of proteins with broad applications. Silica-binding peptides (SBPs) have emerged as an important tool enabling convenient binding of proteins onto a silica surface. Surprisingly, we found that removal of polyhistidines, a common tag for protein purification, dramatically decrease the binding affinity of a SBP-tagged nanobody onto a silica surface. We hypothesized that polyhistidines and SBPs can be combined to enhance affinity. Through a series of purposely designed SBPs, we identified that the relative orientation of amino acids is a key factor affecting the surface binding strength. One re-engineered SBP, SBP4, exhibits a 4000-fold improvement compared to the original sequence. Guided by physical insights, the work provides a simple strategy that can dramatically improve affinity between a SBP and a silica surface, promising a new way for controllable immobilization of proteins, as demonstrated using nanobodies.
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Affiliation(s)
- Chang Liu
- Department of Chemical and Biological Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - David L Steer
- Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Haipeng Song
- Shenzhen Innova Nanobodi Company, 1301 Sightseeing Road, Shengzhen, Guangdong 518000, People's Republic of China
| | - Lizhong He
- Department of Chemical and Biological Engineering, Monash University, Clayton, Victoria 3800, Australia
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26
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Pertl-Obermeyer H, Gimeno A, Kuchler V, Servili E, Huang S, Fang H, Lang V, Sydow K, Pöckl M, Schulze WX, Obermeyer G. pH modulates interaction of 14-3-3 proteins with pollen plasma membrane H+ ATPases independently from phosphorylation. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:168-181. [PMID: 34467995 DOI: 10.1093/jxb/erab387] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Pollen grains transport the sperm cells through the style tissue via a fast-growing pollen tube to the ovaries where fertilization takes place. Pollen tube growth requires a precisely regulated network of cellular as well as molecular events including the activity of the plasma membrane H+ ATPase, which is known to be regulated by reversible protein phosphorylation and subsequent binding of 14-3-3 isoforms. Immunodetection of the phosphorylated penultimate threonine residue of the pollen plasma membrane H+ ATPase (LilHA1) of Lilium longiflorum pollen revealed a sudden increase in phosphorylation with the start of pollen tube growth. In addition to phosphorylation, pH modulated the binding of 14-3-3 isoforms to the regulatory domain of the H+ ATPase, whereas metabolic components had only small effects on 14-3-3 binding, as tested with in vitro assays using recombinant 14-3-3 isoforms and phosphomimicking substitutions of the threonine residue. Consequently, local H+ influxes and effluxes as well as pH gradients in the pollen tube tip are generated by localized regulation of the H+ ATPase activity rather than by heterogeneous localized distribution in the plasma membrane.
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Affiliation(s)
- Heidi Pertl-Obermeyer
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
- MorphoPhysics, Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Str. 2a, 5020 Salzburg, Austria
| | - Ana Gimeno
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
| | - Verena Kuchler
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
| | - Evrim Servili
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
- Inst. Recherche Experimentale & Clinique, University of Louvain, Ave. Hippocrate, Woluwe-Saint Lambert, Belgium
| | - Shuai Huang
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
- Southern University of Science and Technology, Shenzen, PR China
| | - Han Fang
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
- Spinal Chord Injury & Tissue Regeneration Centre, Paracelsus Medical University, Strubergasse, Salzburg, Austria
| | - Veronika Lang
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
- STRATEC GmbH, Sonystraße 20, Anif, Austria
| | - Katharina Sydow
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
| | - Magdalena Pöckl
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
| | - Waltraud X Schulze
- Plant Systems Biology, University of Hohenheim, Garbenstraße 30, 70599 Stuttgart, Germany
| | - Gerhard Obermeyer
- Membrane Biophysics, Department of Biosciences, University of Salzburg, Billrothstr. 11, 5020 Salzburg, Austria
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27
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Reverse Ordered Sequential Mechanism for Lactoperoxidase with Inhibition by Hydrogen Peroxide. Antioxidants (Basel) 2021; 10:antiox10111646. [PMID: 34829517 PMCID: PMC8614691 DOI: 10.3390/antiox10111646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 11/25/2022] Open
Abstract
Lactoperoxidase (LPO, FeIII in its resting state in the absence of substrates)—an enzyme secreted from human mammary, salivary, and other mucosal glands—catalyzes the oxidation of thiocyanate (SCN−) by hydrogen peroxide (H2O2) to produce hypothiocyanite (OSCN−), which functions as an antimicrobial agent. The accepted catalytic mechanism, called the halogen cycle, comprises a two-electron oxidation of LPO by H2O2 to produce oxoiron(IV) radicals, followed by O-atom transfer to SCN−. However, the mechanism does not explain biphasic kinetics and inhibition by H2O2 at low concentration of reducing substrate, conditions that may be biologically relevant. We propose an ordered sequential mechanism in which the order of substrate binding is reversed, first SCN− and then H2O2. The sequence of substrate binding that is described by the halogen cycle mechanism is actually inhibitory.
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28
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Lechner VM, Nappi M, Deneny PJ, Folliet S, Chu JCK, Gaunt MJ. Visible-Light-Mediated Modification and Manipulation of Biomacromolecules. Chem Rev 2021; 122:1752-1829. [PMID: 34546740 DOI: 10.1021/acs.chemrev.1c00357] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemically modified biomacromolecules-i.e., proteins, nucleic acids, glycans, and lipids-have become crucial tools in chemical biology. They are extensively used not only to elucidate cellular processes but also in industrial applications, particularly in the context of biopharmaceuticals. In order to enable maximum scope for optimization, it is pivotal to have a diverse array of biomacromolecule modification methods at one's disposal. Chemistry has driven many significant advances in this area, and especially recently, numerous novel visible-light-induced photochemical approaches have emerged. In these reactions, light serves as an external source of energy, enabling access to highly reactive intermediates under exceedingly mild conditions and with exquisite spatiotemporal control. While UV-induced transformations on biomacromolecules date back decades, visible light has the unmistakable advantage of being considerably more biocompatible, and a spectrum of visible-light-driven methods is now available, chiefly for proteins and nucleic acids. This review will discuss modifications of native functional groups (FGs), including functionalization, labeling, and cross-linking techniques as well as the utility of oxidative degradation mediated by photochemically generated reactive oxygen species. Furthermore, transformations at non-native, bioorthogonal FGs on biomacromolecules will be addressed, including photoclick chemistry and DNA-encoded library synthesis as well as methods that allow manipulation of the activity of a biomacromolecule.
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Affiliation(s)
- Vivian M Lechner
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Manuel Nappi
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Patrick J Deneny
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Sarah Folliet
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - John C K Chu
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Matthew J Gaunt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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29
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Singh A, Joseph JP, Gupta D, Miglani C, Mavlankar NA, Pal A. Photothermally switchable peptide nanostructures towards modulating catalytic hydrolase activity. NANOSCALE 2021; 13:13401-13409. [PMID: 34477745 DOI: 10.1039/d1nr03655f] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Enzymes are the most efficient catalysts in nature that possess an impressive range of catalytic activities, albeit limited by stability in adverse conditions. Functional peptides have emerged as alternative robust biocatalysts to mimic complex enzymes. Here, a rational design of minimalistic amyloid-inspired peptides 1-2 is demonstrated, which leads to pathway-driven self-assembly triggered by heat, light and chemical cues to render 1D and 2D nanostructures by the interplay of hydrogen bonding, host-guest interaction and reversible photodimerization. Such in situ transformable peptide nanostructures by means of external cues are envisaged as a catalytic amyloid for the first time to mimic the hydrolase enzyme activity. Michaelis Menten's enzyme kinetic parameters for the hydrolysis rate correlate the external cue-mediated structure-function augmentation with the twisted bundles, 1TB being the most efficient biocatalyst among all the dimensionally diverse nanostructures. Unlike the natural enzyme, the peptide nanostructures exhibited the robust nature of the hydrolase activity over a broad range of temperature and pH. Finally, the peptide nanostructures are explored as efficient heterogeneous flow catalysts to improve the turnover number for the hydrolase activity.
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Affiliation(s)
- Ashmeet Singh
- Chemical Biology Unit, Institute of Nano Science and Technology, Knowledge City, Sector 81, Mohali, Punjab 140306, India.
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30
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Jha RK, Yankey A, Shabazz K, Naranjo L, Shin SM, Velappan N, Bradbury ARM, Strauss CEM. Engineered pH-Sensitive Protein G/IgG Interaction. ACS Chem Biol 2021; 16:1142-1146. [PMID: 34152722 DOI: 10.1021/acschembio.0c00943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
While natural protein-protein interactions have evolved to be induced by complex stimuli, rational design of interactions that can be switched-on-demand still remain challenging in the protein design world. Here, we demonstrate that a computationally redesigned natural interface for improved binding affinity could further be mutated to adopt a pH switchable interaction. The redesigned interface of Protein G/human IgG Fc domain (referred to as PrG/hIgG), when incorporated with histidine and glutamic acid on PrG (PrG-EHHE), showed a switch in binding affinity by 50-fold when the pH was altered from mild acidic to mild basic. The wild-type (WT) interface showed a negligible switch. The overall binding affinity under mild acidic pH for PrG-EHHE outperformed the wild-type PrG (PrG-WT) interaction. The new reagent PrG-EHHE can be revolutionary in IgG purification, since the standard method of using an extreme acidic pH for elution can be circumvented.
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Affiliation(s)
- Ramesh K. Jha
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Allison Yankey
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Kalifa Shabazz
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Leslie Naranjo
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sang-Min Shin
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Nileena Velappan
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Andrew R. M. Bradbury
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Charlie E. M. Strauss
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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31
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Terranova U. Residues surrounding the active centre of carbon monoxide dehydrogenase are key in converting [Formula: see text] to CO. J Biol Inorg Chem 2021; 26:617-624. [PMID: 34255144 DOI: 10.1007/s00775-021-01878-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/17/2021] [Indexed: 10/20/2022]
Abstract
The enzyme carbon monoxide dehydrogenase is capable of efficiently converting [Formula: see text] to CO and, therefore, can enable an affordable [Formula: see text] recycling strategy. The reduction of [Formula: see text] occurs at a peculiar nickel-iron-sulfur cluster, following a mechanism that remains little understood. In this study, we have used ab initio molecular dynamics simulations to explore the free energy landscape of the reaction. We predict the existence of a COOH ligand that strongly interacts with the surrounding protein residues and favours a mechanism where a [Formula: see text] molecule is eliminated before CO. We have taken advantages of the insights offered by our simulations to revisit the catalytic mechanism and the role of the residues surrounding the active centre in particular, thus assisting in the design of inorganic catalysts that mimic the enzyme.
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Affiliation(s)
- Umberto Terranova
- Faculty of Medicine and Health Sciences, Crewe Campus, University of Buckingham, Crewe, CW1 5DU, UK.
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32
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Hübner R, Paretzki A, von Kiedrowski V, Maspero M, Cheng X, Davarci G, Braun D, Damerow H, Judmann B, Filippou V, Dallanoce C, Schirrmacher R, Wängler B, Wängler C. PESIN Conjugates for Multimodal Imaging: Can Multimerization Compensate Charge Influences on Cell Binding Properties? A Case Study. Pharmaceuticals (Basel) 2021; 14:ph14060531. [PMID: 34199635 PMCID: PMC8226452 DOI: 10.3390/ph14060531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
Recently, anionic charges were found to negatively influence the in vitro gastrin-releasing peptide receptor (GRPR) binding parameters of dually radioisotope and fluorescent dye labeled GRPR-specific peptide dimers. From this, the question arose if this adverse impact on in vitro GRP receptor affinities could be mitigated by a higher valency of peptide multimerization. For this purpose, we designed two different hybrid multimodal imaging units (MIUs), comprising either one or two click chemistry-compatible functional groups and reacted them with PESIN (PEG3-BBN7-14, PEG = polyethylene glycol) dimers to obtain a dually labeled peptide homodimer or homotetramer. Using this approach, other dually labeled peptide monomers, dimers, and tetramers can also be obtained, and the chelator and fluorescent dye can be adapted to specific requirements. The MIUs, as well as their peptidic conjugates, were evaluated in terms of their photophysical properties, radiolabeling efficiency with 68Ga and 64Cu, hydrophilicity, and achievable GRP receptor affinities. Here, the hydrophilicity and the GRP receptor binding affinities were found to be especially strongly influenced by the number of negative charges and peptide copies, showing logD (1-octanol-water-distribution coefficient) and IC50 (half maximal inhibitory concentration) values of -2.2 ± 0.1 and 59.1 ± 1.5 nM for the homodimer, and -1.9 ± 0.1 and 99.8 ± 3.2 nM for the homotetramer, respectively. From the obtained data, it can be concluded that the adverse influence of negatively charged building blocks on the in vitro GRP receptor binding properties of dually labeled PESIN multimers can, at least partly, be compensated for by the number of introduced peptide binding motives and the used molecular design.
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Affiliation(s)
- Ralph Hübner
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
- Institute of Inorganic Chemistry, University Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany; (A.P.); (V.F.)
- Correspondence: (R.H.); (C.W.)
| | - Alexa Paretzki
- Institute of Inorganic Chemistry, University Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany; (A.P.); (V.F.)
| | - Valeska von Kiedrowski
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Marco Maspero
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy;
| | - Xia Cheng
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Güllü Davarci
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Diana Braun
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Helen Damerow
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
| | - Benedikt Judmann
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Vasileios Filippou
- Institute of Inorganic Chemistry, University Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany; (A.P.); (V.F.)
| | - Clelia Dallanoce
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy;
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada;
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (V.v.K.); (X.C.); (G.D.); (B.W.)
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; (M.M.); (D.B.); (H.D.); (B.J.)
- Correspondence: (R.H.); (C.W.)
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Alcala-Torano R, Halloran N, Gwerder N, Sommer DJ, Ghirlanda G. Light-Driven CO 2 Reduction by Co-Cytochrome b 562. Front Mol Biosci 2021; 8:609654. [PMID: 33937320 PMCID: PMC8082397 DOI: 10.3389/fmolb.2021.609654] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/11/2021] [Indexed: 11/23/2022] Open
Abstract
The current trend in atmospheric carbon dioxide concentrations is causing increasing concerns for its environmental impacts, and spurring the developments of sustainable methods to reduce CO2 to usable molecules. We report the light-driven CO2 reduction in water in mild conditions by artificial protein catalysts based on cytochrome b 562 and incorporating cobalt protoporphyrin IX as cofactor. Incorporation into the protein scaffolds enhances the intrinsic reactivity of the cobalt porphyrin toward proton reduction and CO generation. Mutations around the binding site modulate the activity of the enzyme, pointing to the possibility of further improving catalytic activity through rational design or directed evolution.
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Affiliation(s)
| | | | | | | | - Giovanna Ghirlanda
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States
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Amundarain MJ, Caffarena ER, Costabel MD. How does α 1Histidine102 affect the binding of modulators to α 1β 2γ 2 GABA A receptors? molecular insights from in silico experiments. Phys Chem Chem Phys 2021; 23:3993-4006. [PMID: 33554986 DOI: 10.1039/d0cp05081d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The activation of GABAA receptors by the neurotransmitter gamma-aminobutyric acid mediates the rapid inhibition response in the central nervous system of mammals. Many neurological and mental health disorders arise from alterations in the structure or function of these pentameric ion channels. GABAA receptors are targets for numerous drugs, including benzodiazepines, which bind to α1β2γ2 GABAA receptors with high affinity to a site in the extracellular domain, between subunits α1 and γ2. It has been established experimentally that the binding of these drugs depends on the presence of one particular amino acid in the α1 subunit: histidine 102. However, the specific role it plays in the intermolecular interaction has not been elucidated. In this work, we applied in silico methods to understand whether certain protonation and rotamer states of α1His102 facilitate the binding of modulators. We analysed diazepam binding, a benzodiazepine, and the antagonist flumazenil to the GABAA receptor using molecular dynamics simulations and adaptive biasing force simulations. The binding free energy follows changes in the protonation state for both ligands, and rotameric states of α1His102 were specific for the different compounds, suggesting distinct preferences for positive allosteric modulators and antagonists. Moreover, in the presence of diazepam and favoured by a neutral tautomer, we identified a water molecule that links loops A, B, and C and may be relevant to the modulation mechanism.
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Affiliation(s)
- María Julia Amundarain
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Av. L. N. Alem 1253, B8000CPB - Bahía Blanca, Argentina.
| | - Ernesto Raúl Caffarena
- Programa de Computação Científica - PROCC, Fundação Oswaldo Cruz, Manguinhos, CEP 21040-360, Av. Brasil 4365, Rio de Janeiro, RJ, Brazil
| | - Marcelo Daniel Costabel
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Av. L. N. Alem 1253, B8000CPB - Bahía Blanca, Argentina.
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Entry of Phenuiviruses into Mammalian Host Cells. Viruses 2021; 13:v13020299. [PMID: 33672975 PMCID: PMC7918600 DOI: 10.3390/v13020299] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 12/22/2022] Open
Abstract
Phenuiviridae is a large family of arthropod-borne viruses with over 100 species worldwide. Several cause severe diseases in both humans and livestock. Global warming and the apparent geographical expansion of arthropod vectors are good reasons to seriously consider these viruses potential agents of emerging diseases. With an increasing frequency and number of epidemics, some phenuiviruses represent a global threat to public and veterinary health. This review focuses on the early stage of phenuivirus infection in mammalian host cells. We address current knowledge on each step of the cell entry process, from virus binding to penetration into the cytosol. Virus receptors, endocytosis, and fusion mechanisms are discussed in light of the most recent progress on the entry of banda-, phlebo-, and uukuviruses, which together constitute the three prominent genera in the Phenuiviridae family.
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Crystal structures of non-oxidative decarboxylases reveal a new mechanism of action with a catalytic dyad and structural twists. Sci Rep 2021; 11:3056. [PMID: 33542397 PMCID: PMC7862292 DOI: 10.1038/s41598-021-82660-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/22/2021] [Indexed: 12/01/2022] Open
Abstract
Hydroxybenzoic acids, like gallic acid and protocatechuic acid, are highly abundant natural compounds. In biotechnology, they serve as critical precursors for various molecules in heterologous production pathways, but a major bottleneck is these acids’ non-oxidative decarboxylation to hydroxybenzenes. Optimizing this step by pathway and enzyme engineering is tedious, partly because of the complicating cofactor dependencies of the commonly used prFMN-dependent decarboxylases. Here, we report the crystal structures (1.5–1.9 Å) of two homologous fungal decarboxylases, AGDC1 from Arxula adenivorans, and PPP2 from Madurella mycetomatis. Remarkably, both decarboxylases are cofactor independent and are superior to prFMN-dependent decarboxylases when heterologously expressed in Saccharomyces cerevisiae. The organization of their active site, together with mutational studies, suggests a novel decarboxylation mechanism that combines acid–base catalysis and transition state stabilization. Both enzymes are trimers, with a central potassium binding site. In each monomer, potassium introduces a local twist in a β-sheet close to the active site, which primes the critical H86-D40 dyad for catalysis. A conserved pair of tryptophans, W35 and W61, acts like a clamp that destabilizes the substrate by twisting its carboxyl group relative to the phenol moiety. These findings reveal AGDC1 and PPP2 as founding members of a so far overlooked group of cofactor independent decarboxylases and suggest strategies to engineer their unique chemistry for a wide variety of biotechnological applications.
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Kostko O, Xu B, Ahmed M. Local electronic structure of histidine in aqueous solution. Phys Chem Chem Phys 2021; 23:8847-8853. [DOI: 10.1039/d1cp00361e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
X-Ray spectroscopy coupled with DFT calculations reveals the pH dependent electronic structure of an amino acid in an aqueous environment.
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Affiliation(s)
- O. Kostko
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Advanced Light Source
| | - B. Xu
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - M. Ahmed
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
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Kurbasic M, Garcia AM, Viada S, Marchesan S. Tripeptide Self-Assembly into Bioactive Hydrogels: Effects of Terminus Modification on Biocatalysis. Molecules 2020; 26:E173. [PMID: 33396543 PMCID: PMC7794889 DOI: 10.3390/molecules26010173] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022] Open
Abstract
Bioactive hydrogels based on the self-assembly of tripeptides have attracted great interest in recent years. In particular, the search is active for sequences that are able to mimic enzymes when they are self-organized in a nanostructured hydrogel, so as to provide a smart catalytic (bio)material whose activity can be switched on/off with assembly/disassembly. Within the diverse enzymes that have been targeted for mimicry, hydrolases find wide application in biomaterials, ranging from their use to convert prodrugs into active compounds to their ability to work in reverse and catalyze a plethora of reactions. We recently reported the minimalistic l-His-d-Phe-d-Phe for its ability to self-organize into thermoreversible and biocatalytic hydrogels for esterase mimicry. In this work, we analyze the effects of terminus modifications that mimic the inclusion of the tripeptide in a longer sequence. Therefore, three analogues, i.e., N-acetylated, C-amidated, or both, were synthesized, purified, characterized by several techniques, and probed for self-assembly, hydrogelation, and esterase-like biocatalysis. This work provides useful insights into how chemical modifications at the termini affect self-assembly into biocatalytic hydrogels, and these data may become useful for the future design of supramolecular catalysts for enhanced performance.
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Affiliation(s)
| | | | | | - Silvia Marchesan
- Chemical & Pharmaceutical Sciences Department, University of Trieste, 34127 Trieste, Italy; (M.K.); (A.M.G.); (S.V.)
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Nanovesicle-Mediated Delivery Systems for CRISPR/Cas Genome Editing. Pharmaceutics 2020; 12:pharmaceutics12121233. [PMID: 33353099 PMCID: PMC7766488 DOI: 10.3390/pharmaceutics12121233] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 12/14/2022] Open
Abstract
Genome-editing technology has emerged as a potential tool for treating incurable diseases for which few therapeutic modalities are available. In particular, discovery of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system together with the design of single-guide RNAs (sgRNAs) has sparked medical applications of genome editing. Despite the great promise of the CRISPR/Cas system, its clinical application is limited, in large part, by the lack of adequate delivery technology. To overcome this limitation, researchers have investigated various systems, including viral and nonviral vectors, for delivery of CRISPR/Cas and sgRNA into cells. Among nonviral delivery systems that have been studied are nanovesicles based on lipids, polymers, peptides, and extracellular vesicles. These nanovesicles have been designed to increase the delivery of CRISPR/Cas and sgRNA through endosome escape or using various stimuli such as light, pH, and environmental features. This review covers the latest research trends in nonviral, nanovesicle-based delivery systems that are being applied to genome-editing technology and suggests directions for future progress.
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40
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Nagpal S, Luong TDN, Sadqi M, Muñoz V. Downhill (Un)Folding Coupled to Binding as a Mechanism for Engineering Broadband Protein Conformational Transducers. ACS Synth Biol 2020; 9:2427-2439. [PMID: 32822536 DOI: 10.1021/acssynbio.0c00190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Canonical proteins fold and function as conformational switches that toggle between their folded (on) and unfolded (off) states, a mechanism that also provides the basis for engineering transducers for biosensor applications. One of the limitations of such transducers, however, is their relatively narrow operational range, limited to ligand concentrations 20-fold below or above their C50. Previously, we discovered that certain fast-folding proteins lose/gain structure gradually (downhill folding), which led us to postulate their operation as conformational rheostats capable of processing inputs/outputs in analog fashion. Conformational rheostats could make transducers with extended sensitivity. Here we investigate this hypothesis by engineering pH transducing into the naturally pH insensitive, downhill folding protein gpW. Particularly, we engineered histidine grafts into its hydrophobic core to induce unfolding via histidine ionization. We designed and tested the effects of ionization via computational modeling and studied experimentally the four most promising single grafts and two double grafts. All tested mutants become reversible pH transducers in the 4-9 range, and their response increases proportionally to how buried the histidine graft is. Importantly, the pH-dependent reversible (un)folding occurs in rheostatic fashion, so the engineered transducers can detect up to 6 orders of magnitude in [H+] for single grafts, and even more for double grafts. Our results demonstrate that downhill (un)folding coupled to binding produces the gradual, analog responses to the ligand (here H+) that are expected of conformational rheostats, and which make them a powerful mechanism for engineering transducers with sensitivity over many orders of magnitude in ligand concentration (broadband).
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Affiliation(s)
- Suhani Nagpal
- Bioengineering Graduate Program, University of California at Merced, Merced, 95343 California, United States
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California at Merced, Merced, 95343 California, United States
| | - Thinh D. N. Luong
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California at Merced, Merced, 95343 California, United States
- Chemistry and Chemical Biology Graduate Program, University of California at Merced, Merced, 95343 California, United States
| | - Mourad Sadqi
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California at Merced, Merced, 95343 California, United States
- Department of Bioengineering, University of California at Merced, Merced, 95343 California, United States
| | - Victor Muñoz
- Bioengineering Graduate Program, University of California at Merced, Merced, 95343 California, United States
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California at Merced, Merced, 95343 California, United States
- Chemistry and Chemical Biology Graduate Program, University of California at Merced, Merced, 95343 California, United States
- Department of Bioengineering, University of California at Merced, Merced, 95343 California, United States
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He J, Xu S, Mixson AJ. The Multifaceted Histidine-Based Carriers for Nucleic Acid Delivery: Advances and Challenges. Pharmaceutics 2020; 12:E774. [PMID: 32823960 PMCID: PMC7465012 DOI: 10.3390/pharmaceutics12080774] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022] Open
Abstract
Histidines incorporated into carriers of nucleic acids may enhance the extracellular stability of the nanoparticle, yet aid in the intracellular disruption of the nanoparticle, enabling the release of the nucleic acid. Moreover, protonation of histidines in the endosomes may result in endosomal swelling with subsequent lysis. These properties of histidine are based on its five-member imidazole ring in which the two nitrogen atoms may form hydrogen bonds or act as a base in acidic environments. A wide variety of carriers have integrated histidines or histidine-rich domains, which include peptides, polyethylenimine, polysaccharides, platform delivery systems, viral phages, mesoporous silica particles, and liposomes. Histidine-rich carriers have played key roles in our understanding of the stability of nanocarriers and the escape of the nucleic acids from endosomes. These carriers show great promise and offer marked potential in delivering plasmids, siRNA, and mRNA to their intracellular targets.
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Affiliation(s)
| | | | - A. James Mixson
- Department of Pathology, University Maryland School of Medicine, 10 S. Pine St., University of Maryland, Baltimore, MD 21201, USA; (J.H.); (S.X.)
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Schepers AV, Lorenz C, Köster S. Tuning intermediate filament mechanics by variation of pH and ion charges. NANOSCALE 2020; 12:15236-15245. [PMID: 32642745 DOI: 10.1039/d0nr02778b] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The cytoskeleton is formed by three types of filamentous proteins - microtubules, actin filaments, and intermediate filaments (IFs) - and enables cells to withstand external and internal forces. Vimentin is the most abundant IF protein in humans and assembles into 10 nm diameter filaments with remarkable mechanical properties, such as high extensibility and stability. It is, however, unclear to which extent these properties are influenced by the electrostatic environment. Here, we study the mechanical properties of single vimentin filaments by employing optical trapping combined with microfluidics. Force-strain curves, recorded at varying ion concentrations and pH values, reveal that the mechanical properties of single vimentin IFs are influenced by pH and ion concentration. By combination with Monte Carlo simulations, we relate these altered mechanics to electrostatic interactions of subunits within the filaments. We thus suggest possible mechanisms that allow cells to locally tune their stiffness without remodeling the entire cytoskeleton.
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Affiliation(s)
- Anna V Schepers
- Institute for X-Ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
| | - Charlotta Lorenz
- Institute for X-Ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
| | - Sarah Köster
- Institute for X-Ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
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43
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Rosen T, Nolan EM. Metal Sequestration and Antimicrobial Activity of Human Calprotectin Are pH-Dependent. Biochemistry 2020; 59:2468-2478. [PMID: 32491853 DOI: 10.1021/acs.biochem.0c00359] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Human calprotectin (CP, S100A8/S100A9 oligomer) is an abundant innate immune protein that sequesters transition metal ions in the extracellular space to limit nutrient availability and the growth of invading microbial pathogens. Our current understanding of the metal-sequestering ability of CP is based on biochemical and functional studies performed at neutral or near-neutral pH. Nevertheless, CP can be present throughout the human body and is expressed at infection and inflammation sites that tend to be acidic. Here, we evaluate the metal binding and antimicrobial properties of CP in the pH range of 5.0-7.0. We show that Ca(II)-induced tetramerization, an important process for the extracellular functions of CP, is perturbed by acidic conditions. Moreover, a low pH impairs the antimicrobial activity of CP against some bacterial pathogens, including Staphylococcus aureus and Salmonella enterica serovar Typhimurium. At a mildly acidic pH, CP loses the ability to deplete Mn from microbial growth medium, indicating that Mn(II) sequestration is attenuated under acidic conditions. Evaluation of the Mn(II) binding properties of CP at pH 5.0-7.0 indicates that mildly acidic conditions decrease the Mn(II) binding affinity of the His6 site. Lastly, CP is less effective at preventing capture of Mn(II) by the bacterial solute-binding proteins MntC and PsaA at low pH. These results indicate that acidic conditions compromise the ability of CP to sequester Mn(II) and starve microbial pathogens of this nutrient. This work highlights the importance of considering the local pH of biological sites when describing the interplay between CP and microbes in host-pathogen interactions.
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Affiliation(s)
- Tomer Rosen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Ribone SR, Ferronato MJ, Vitale C, Fall Y, Curino AC, Facchinetti MM, Quevedo MA. Vitamin D receptor exhibits different pharmacodynamic features in tumoral and normal microenvironments: A molecular modeling study. J Steroid Biochem Mol Biol 2020; 200:105649. [PMID: 32142933 DOI: 10.1016/j.jsbmb.2020.105649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/28/2020] [Accepted: 03/03/2020] [Indexed: 12/20/2022]
Abstract
The vitamin D receptor (VDR) constitutes a promising therapeutic target for the treatment of cancer. Unfortunately, its natural agonist calcitriol does not have clinical utility due to its potential to induce hypercalcemic effects at the concentrations required to display antitumoral activity. For this reason, the search for new calcitriol analogues with adequate therapeutic profiles has been actively pursued by the scientific community. We have previously reported the obtaining and the biological activity evaluation of new calcitriol analogues by modification of its sidechain, which exhibited relevant antiproliferative and selectivity profiles against tumoral and normal cells. In this work we conducted molecular modeling studies (i.e. molecular docking, molecular dynamics, constant pH molecular dynamics (CpHMD) and free energy of binding analysis) to elucidate at an atomistic level the molecular basis related to the potential of the new calcitriol analogues to achieve selectivity between tumoral and normal cells. Two histidine residues (His305 and His397) were found to exhibit a particular tautomeric configuration that produces the observed bioactivity. Also, different acid-based properties were observed for His305 and His307 with His305 showing an increased acidity (pKa 5.2) compared to His397 (pKa 6.8) and to the typical histidine residue. This behavior favored the pharmacodynamic interaction of the calcitriol analogues exhibiting selectivity for tumoral cells when VDR was modeled at the more acidic tumoral environment (pH ≅ 6) compared to the case when VDR was modeled at pH 7.4 (normal cell environment). On the other hand, non-selective compounds, including calcitriol, exhibited a similar interaction pattern with VDR when the receptor was modeled at both pH conditions. The results presented constitute the first evidence on the properties of the VDR receptor in different physicochemical environments and thus represent a significant contribution to the in silico screening and design of new calcitriol analogues.
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Affiliation(s)
- Sergio R Ribone
- Unidad de Investigación y Desarrollo en Tecnología Farmacéutica (UNITEFA), CONICET and Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba. X5000HUA, Córdoba, Argentina
| | - Maria J Ferronato
- Laboratorio de Biología del Cáncer, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS), CONICET, Departamento de Biología, Bioquímica y Farmacia (UNS), Bahía Blanca, Argentina
| | - Cristian Vitale
- Laboratorio de Química Orgánica, Instituto de Química del Sur (INQUISUR), Universidad Nacional del Sur (UNS), CONICET, Departamento de Química (UNS), Bahía Blanca, Argentina
| | - Yagamare Fall
- Departamento de Química Orgánica, Facultad de Química e Instituto de Investigación Biomédica (IBI), Universidad de Vigo, Campus Lagoas de Marcosende, 36310, Vigo, Spain
| | - Alejandro C Curino
- Laboratorio de Biología del Cáncer, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS), CONICET, Departamento de Biología, Bioquímica y Farmacia (UNS), Bahía Blanca, Argentina
| | - Maria M Facchinetti
- Laboratorio de Biología del Cáncer, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS), CONICET, Departamento de Biología, Bioquímica y Farmacia (UNS), Bahía Blanca, Argentina
| | - Mario A Quevedo
- Unidad de Investigación y Desarrollo en Tecnología Farmacéutica (UNITEFA), CONICET and Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba. X5000HUA, Córdoba, Argentina.
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45
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Malash MN, Hussein NA, Muawia S, Nasr MI, Siam R. An optimized protocol for high yield expression and purification of an extremophilic protein. Protein Expr Purif 2020; 169:105585. [PMID: 31987929 DOI: 10.1016/j.pep.2020.105585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 01/22/2020] [Accepted: 01/22/2020] [Indexed: 11/18/2022]
Affiliation(s)
- Mohamed N Malash
- Microbiology and Immunology Department, Faculty of Pharmacy, Ahram Canadian University, 6th of October City, Giza, Egypt; Biology Department, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo, Egypt; Molecular Biology Department, Genetic Engineering and Biotechnology Research Institute, Sadat City University, Menofia, Egypt
| | - Nahla A Hussein
- Molecular Biology Department, Genetic Engineering and Biotechnology Research Division, National Research Centre, Cairo, Egypt
| | - Shaden Muawia
- Molecular Biology Department, Genetic Engineering and Biotechnology Research Institute, Sadat City University, Menofia, Egypt
| | - Mahmoud I Nasr
- Molecular Biology Department, Genetic Engineering and Biotechnology Research Institute, Sadat City University, Menofia, Egypt
| | - Rania Siam
- Biology Department, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo, Egypt; University of Medicine and Health Sciences, St. Kitts, West Indies.
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46
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Adsorption of colloidal proteins in ion-exchange chromatography under consideration of charge regulation. J Chromatogr A 2020; 1611:460608. [DOI: 10.1016/j.chroma.2019.460608] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/26/2019] [Accepted: 10/07/2019] [Indexed: 01/21/2023]
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47
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Lim YY, Lim TS, Choong YS. Human IgG1 Fc pH-dependent optimization from a constant pH molecular dynamics simulation analysis. RSC Adv 2020; 10:13066-13075. [PMID: 35492131 PMCID: PMC9051383 DOI: 10.1039/c9ra10712f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/11/2020] [Indexed: 11/21/2022] Open
Abstract
The binding of IgG Fc with FcRn enables the long circulating half-life of IgG, where the Fc–FcRn complex interacts in a pH-dependent manner. This complex shows stronger interaction at pH ≤ 6.5 and weaker interaction at pH ≥ 7.4. The Fc–FcRn binding mechanism that promotes the long circulating half-life of IgG has prompted several IgG Fc-related mutational studies to focus on the pH-dependent Fc–FcRn complex interactions in order to improve the pharmacokinetic properties of Fc. Hence, in this study, we applied the in silico constant pH molecular dynamics (CpHMD) simulation approach to evaluate the human Fc–FcRn complex binding (pH 6.0) and dissociating (pH 7.5) mechanism at the molecular level. The analysis showed that the protonated state of the titratable residues changes from pH 6.0 to pH 7.5, where the disrupting energy for Fc–FcRn complex formation was found to be due to the electrostatic repulsion between the complex. According to the analysis, an Fc variant was computationally designed with an improved binding affinity at pH 6.0, which is still able to dissociate at pH 7.5 with FcRn at the in silico level. The binding free energy calculation via the MMPB/GBSA approach showed that the designed Fc mutant (MutM4) has increased binding affinity only at pH 6.0 compared with the reported mutant (YTE) Fc. This work demonstrates an alternative Fc design with better binding properties for FcRn, which can be useful for future experimental evaluation and validation. An in silico IgG-Fc variant with better affinity at pH 6.0 but retained the dissociation at pH 7.5 was designed.![]()
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Affiliation(s)
- Yee Ying Lim
- Institute for Research in Molecular Medicine (INFORMM)
- Universiti Sains Malaysia
- 11800 Minden
- Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine (INFORMM)
- Universiti Sains Malaysia
- 11800 Minden
- Malaysia
| | - Yee Siew Choong
- Institute for Research in Molecular Medicine (INFORMM)
- Universiti Sains Malaysia
- 11800 Minden
- Malaysia
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48
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Colabroy KL, Horwitz AD, Basciano VR, Fu Y, Travitz KM, Robinson MK, Shimanski BA, Hoffmann TW. A New Way of Belonging: Active-Site Investigation of L-DOPA Dioxygenase, a VOC Family Enzyme from Lincomycin Biosynthesis. Biochemistry 2019; 58:4794-4798. [DOI: 10.1021/acs.biochem.9b00456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Keri L. Colabroy
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Alyssa D. Horwitz
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Victoria R. Basciano
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Yizhi Fu
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Kelly M. Travitz
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Miranda K. Robinson
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Brittany A. Shimanski
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Thomas W. Hoffmann
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
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49
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Ren C, Bobst CE, Kaltashov IA. Exploiting His-Tags for Absolute Quantitation of Exogenous Recombinant Proteins in Biological Matrices: Ruthenium as a Protein Tracer. Anal Chem 2019; 91:7189-7198. [PMID: 31083917 DOI: 10.1021/acs.analchem.9b00504] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Metal labeling and ICP MS detection offer an alternative to commonly accepted techniques that are currently used to quantitate exogenous proteins in vivo, but modifying the protein surface with metal-containing groups inevitably changes its biophysical properties and is likely to affect trafficking and biodistribution. The approach explored in this work takes advantage of the presence of hexa-histidine tags in many recombinant proteins, which have high affinity toward a range of metals. While many divalent metals bind to poly histidine sequences reversibly, oxidation of imidazole-bound CoII or RuII is known to result in a dramatic increase of the binding strength. In order to evaluate the feasibility of using imidazole-bound metal oxidation as a means of attaching permanent tags to polyhistidine segments, a synthetic peptide YPDFEDYWMKHHHHHH was used as a model. RuII can be oxidized under ambient (aerobic) conditions, allowing any oxidation damage to the peptide beyond the metal-binding site to be avoided. The resulting peptide-RuIII complex is very stable, with the single hexa-histidine segment capable of accommodating up to three metal ions. Localization of RuIII within the hexa-histidine segment of the peptide was confirmed by tandem mass spectrometry. The RuIII/peptide binding appears to be irreversible, with both low- and high-molecular weight biologically relevant scavengers failing to strip the metal from the peptide. Application of this protocol to labeling a recombinant form of an 80 kDa protein transferrin allowed RuIII to be selectively placed within the His-tag segment. The metal label remained stable in the presence of ubiquitous scavengers and did not interfere with the receptor binding, while allowing the protein to be readily detected in serum at sub-nM concentrations. The results of this work suggest that ruthenium lends itself as an ideal metal tag for selective labeling of His-tag containing recombinant proteins to enable their sensitive detection and quantitation with ICP MS.
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Affiliation(s)
- Chengfeng Ren
- Department of Chemistry , University of Massachusetts-Amherst , Amherst , Massachusetts 01003 , United States
| | - Cedric E Bobst
- Department of Chemistry , University of Massachusetts-Amherst , Amherst , Massachusetts 01003 , United States
| | - Igor A Kaltashov
- Department of Chemistry , University of Massachusetts-Amherst , Amherst , Massachusetts 01003 , United States
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50
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Cieplak AS. Tau Inclusions in Alzheimer's, Chronic Traumatic Encephalopathy and Pick's Disease. A Speculation on How Differences in Backbone Polarization Underlie Divergent Pathways of Tau Aggregation. Front Neurosci 2019; 13:488. [PMID: 31156372 PMCID: PMC6530265 DOI: 10.3389/fnins.2019.00488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/29/2019] [Indexed: 12/13/2022] Open
Abstract
Tau-related dementias appear to involve specific to each disease aggregation pathways and morphologies of filamentous tau assemblies. To understand etiology of these differences, here we elucidate molecular mechanism of formation of tau PHFs based on the PMO theory of misfolding and aggregation of pleiomorphic proteins associated with neurodegenerative diseases. In this model, fibrillization of tau is initiated by the coupled binding and folding of the MTB domains that yields antiparallel homodimers, in analogy to folding of split inteins. The free energy of binding is minimized when the antiparallel alignment brings about backbone-backbone H-bonding between the MTBD segments of similar "strand" propensities. To assess these propensities, a function of the NMR shielding tensors of the Cα atoms is introduced as the folding potential function FP i ; the Cα tensors are obtained by the quantum mechanical modeling of protein secondary structure (GIAO//B3LYP/D95**). The calculated FP i plots show that the "strand" propensities of the MBTD segments, and hence the homodimer's register, can be affected by the relatively small changes in the environment's pH, as a result of protonation of MBTD's conserved histidines. The assembly of the antiparallel tau dimers into granular aggregates and their subsequent conversion into the parallel cross-β structure of paired helical filaments is expected to follow the same path as the previously described fibrillization of Aβ. Consequently, the core structure of the nascent tau fibril is determined by the register of the tau homodimer. This model accounts for the reported differences in (i) fibril-core structure of in vivo and in vitro filaments, (ii) cross-seeding of isoforms, (iii) effects of reducing/non-reducing conditions, (iv) effects of PHF6 mutations, and (v) homologs' aggregation properties. The proposed model also suggests that in contrast to Alzheimer's and chronic traumatic encephalopathy disease, the assembly of tau prions in Pick's disease would be facilitated by a moderate drop in pH that accompanies e.g., transit in the endosomal system, inflammation response or an ischemic injury.
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Affiliation(s)
- Andrzej Stanisław Cieplak
- Department of Chemistry, Bilkent University, Ankara, Turkey
- Department of Chemistry, Yale University, New Haven, CT, United States
- Department of Chemistry, Brandeis University, Waltham, MA, United States
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