1
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Dong Y, Wang J, Chen L, Chen H, Dang S, Li F. Aptamer-based assembly systems for SARS-CoV-2 detection and therapeutics. Chem Soc Rev 2024. [PMID: 38829187 DOI: 10.1039/d3cs00774j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Nucleic acid aptamers are oligonucleotide chains with molecular recognition properties. Compared with antibodies, aptamers show advantages given that they are readily produced via chemical synthesis and elicit minimal immunogenicity in biomedicine applications. Notably, aptamer-encoded nucleic acid assemblies further improve the binding affinity of aptamers with the targets due to their multivalent synergistic interactions. Specially, aptamers can be engineered with special topological arrangements in nucleic acid assemblies, which demonstrate spatial and valence matching towards antigens on viruses, thus showing potential in the detection and therapeutic applications of viruses. This review presents the recent progress on the aptamers explored for SARS-CoV-2 detection and infection treatment, wherein applications of aptamer-based assembly systems are introduced in detail. Screening methods and chemical modification strategies for aptamers are comprehensively summarized, and the types of aptamers employed against different target domains of SARS-CoV-2 are illustrated. The evolution of aptamer-based assembly systems for the detection and neutralization of SARS-CoV-2, as well as the construction principle and characteristics of aptamer-based DNA assemblies are demonstrated. The typically representative works are presented to demonstrate how to assemble aptamers rationally and elaborately for specific applications in SARS-CoV-2 diagnosis and neutralization. Finally, we provide deep insights into the current challenges and future perspectives towards aptamer-based nucleic acid assemblies for virus detection and neutralization in nanomedicine.
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Affiliation(s)
- Yuhang Dong
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
| | - Jingping Wang
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
| | - Ling Chen
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
| | - Haonan Chen
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
| | - Shuangbo Dang
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
| | - Feng Li
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
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2
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An G. Pharmacokinetics and Pharmacodynamics of GalNAc-Conjugated siRNAs. J Clin Pharmacol 2024; 64:45-57. [PMID: 37589246 DOI: 10.1002/jcph.2337] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/13/2023] [Indexed: 08/18/2023]
Abstract
Small interfering RNAs (siRNAs) represent a new class of drugs with tremendous potential for battling previously "undruggable" diseases. After nearly 2 decades of efforts in addressing the problems of the poor drug profile of naked unmodified siRNAs, this new modality has finally come to fruition, with 5 agents (patisiran, givosiran, lumasiran, inclisiran, and vutrisiran) being approved since 2018, and with many others in the different phases of clinical development. Unlike small-molecule drugs and protein therapeutics, siRNAs have different sizes, distinct mechanisms of action, differing physicochemical and pharmacological properties, and, accordingly, a unique pharmacokinetic/pharmacodynamic (PK/PD) relationship. To support the continuous development of siRNAs, it is important to have a thorough and deep understanding of the PK/PD and clinical pharmacology related features of siRNAs. As most of the current siRNA products are conjugated by N-acetylgalactosamine (GalNAc), this review focuses on the PK/PD relationships and clinical pharmacology of GalNAc-conjugated siRNAs, including their absorption, distribution, metabolism, excretion (ADME) properties, PK/PD models, drug-drug interactions, clinical pharmacology in special populations, and safety evaluation. In addition, necessary background information related to the development of siRNAs as a therapeutic modality, including the mechanisms of action, the advantages of siRNAs, the problems of naked siRNAs, as well as the strategies used to enhance the clinical utility of siRNAs, have also been covered. The goal of this review is to serve as a "primer" on siRNA PK/PD, and I hope the readers, especially those who have a limited background on siRNA therapeutics, will have a fundamental understanding of siRNA PK/PD and clinical pharmacology after reading this review.
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Affiliation(s)
- Guohua An
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, USA
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3
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Li J, Wan H, Zhang H, Wang XL, Liu G, Wu G, He X, Deng Z, Zhao YL. Molecular recognition between bacterial phosphorothioate DNA and sulfur-binding domain (SBD): competition between the water cage and chalcogen-hydrophobic packet. Phys Chem Chem Phys 2022; 24:9176-9187. [PMID: 35383346 DOI: 10.1039/d2cp00291d] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacterial DNA phosphorothioation (PT) physiologically and stereo-specifically replaces a non-bridging oxygen in a phosphate link with a sulfur atom, which can be recognized by a highly conserved sulfur-binding domain (SBD). Here we conducted thermodynamic integration (TI), molecular dynamics simulation, and quantum chemical calculations to decipher the specific molecular interactions between PT-DNA and SBD in Streptomyces coelicolor type IV restriction enzyme ScoMcrA. The TI-calculated binding affinity of (5'-CCGRp-PSGCCGG-3')2 is larger than that of (5'-CCGGCCGG-3')2 by about 7.4-7.7 kcal mol-1. The binding difference dominantly stems from hydration energy of non-phosphorothioate DNA (9.8-10.6 kcal mol-1) in aqueous solution, despite the persistent preference of 2.6-3.2 kcal mol-1 in the DNA-SBD MD simulations. Furthermore, the quantum chemical calculations reveal an unusual non-covalent interaction in the phosphorothioate-binding scenario, where the PS⋯NP165 chalcogen bond prevails the PS⋯HCβ vdW interactions from the adjacent residues H116-R117-Y164-P165-A168. Thus, the chalcogen-hydrophobic interaction pulls PT-DNA into the SBD binding pocket while the water cage pulls a normal DNA molecule out. The synergetic mechanism suggests the special roles of the proline pyrrolidine group in the SBD proteins, consistent with the experimental observations in the X-ray crystallography and structural bioinformatics analysis.
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Affiliation(s)
- Jiayi Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Haibo Wan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Haoqing Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Xiao-Lei Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Geng Wu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Xinyi He
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Yi-Lei Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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4
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Wang X, Yu B, Iwahara J. Hindered Rotations of Protein Asparagine/Glutamine Side-Chain NH 2 Groups: Impact of Hydrogen Bonding with DNA. J Phys Chem Lett 2021; 12:11378-11382. [PMID: 34784468 PMCID: PMC8643942 DOI: 10.1021/acs.jpclett.1c03467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hindered rotation about an sp2 C-N bond is known to occur in arginine (Arg), asparagine (Asn), and glutamine (Gln) side chains of proteins. However, very little is known about the rotational dynamics of Asn and Gln side-chain NH2 groups. Here, using a unique NMR method, we quantitatively characterized the hindered rotations of protein Asn/Gln side-chain NH2 groups. This NMR method yields simple NH2-selective spectra that allow for an accurate determination of the kinetic rate constants for the hindered rotations. Through the NMR measurements at different temperatures, we investigated the energy barriers that restrict the C-N bond rotations of protein side-chain NH2 groups. Through a comparison of the kinetic data for the free and DNA-bound states of the Antp homeodomain, we also examined the impact of hydrogen bonding on the hindered rotations of the side-chain NH2 groups. Our data suggest that the hydrogen bonding increases the energy barriers by 1-6 kJ/mol.
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Affiliation(s)
- Xi Wang
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Binhan Yu
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Junji Iwahara
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555, United States
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5
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Hofstetter RK, Schulig L, Bethmann J, Grimm M, Sager M, Aude P, Keßler R, Kim S, Weitschies W, Link A. Supercritical fluid extraction-supercritical fluid chromatography of saliva: Single-quadrupole mass spectrometry monitoring of caffeine for gastric emptying studies †. J Sep Sci 2021; 44:3700-3716. [PMID: 34355502 DOI: 10.1002/jssc.202100443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/02/2021] [Accepted: 08/02/2021] [Indexed: 11/06/2022]
Abstract
Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO2 for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single-quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of 13 C- and 32 S-labeled internal standards with external standard calibration confirmed the superiority of stable isotope-labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying (R2 = 0.945). In contrast to off-line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO2 -based extraction and separation techniques for potentially infective biomatrices.
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Affiliation(s)
- Robert K Hofstetter
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Lukas Schulig
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Jonas Bethmann
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Michael Grimm
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Maximilian Sager
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Philipp Aude
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Rebecca Keßler
- Department of Diagnostic Radiology and Neuroradiology, University Hospital Greifswald, Greifswald, Germany
| | - Simon Kim
- Department of Trauma, Reconstructive Surgery and Rehabilitation Medicine, University Medicine Greifswald, Greifswald, Germany.,Leibniz Institute for Plasma Science and Technology (INP Greifswald), Greifswald, Germany
| | - Werner Weitschies
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Andreas Link
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
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6
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Zhang MM, Bahal R, Rasmussen TP, Manautou JE, Zhong XB. The growth of siRNA-based therapeutics: Updated clinical studies. Biochem Pharmacol 2021; 189:114432. [PMID: 33513339 DOI: 10.1016/j.bcp.2021.114432] [Citation(s) in RCA: 230] [Impact Index Per Article: 76.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/14/2021] [Accepted: 01/19/2021] [Indexed: 12/11/2022]
Abstract
More than two decades after the natural gene-silencing mechanism of RNA interference was elucidated, small interfering RNA (siRNA)-based therapeutics have finally broken into the pharmaceutical market. With three agents already approved and many others in advanced stages of the drug development pipeline, siRNA drugs are on their way to becoming a standard modality of pharmacotherapy. The majority of late-stage candidates are indicated for rare or orphan diseases, whose patients have an urgent need for novel and effective therapies. Additionally, there are agents that have the potential to meet the need of a broader population. Inclisiran, for instance, is being developed for hypercholesterolemia and has shown benefit in patients who are uncontrolled even after maximal statin therapy. This review provides a brief overview of mechanisms of siRNA action, physiological barriers to its delivery and activity, and the most common chemical modifications and delivery platforms used to overcome these barriers. Furthermore, this review presents comprehensive profiles of the three approved siRNA drugs (patisiran, givosiran, and lumasiran) and the seven other siRNA candidates in Phase 3 clinical trials (vutrisiran, nedosiran, inclisiran, fitusiran, teprasiran, cosdosiran, and tivanisiran), summarizing their modifications and delivery strategies, disease-specific mechanisms of action, updated clinical trial status, and future outlooks.
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Affiliation(s)
- M May Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
| | - Raman Bahal
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
| | - Theodore P Rasmussen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
| | - José E Manautou
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
| | - Xiao-Bo Zhong
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA.
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7
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Abstract
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Molecular association of proteins with nucleic
acids is required
for many biological processes essential to life. Electrostatic interactions
via ion pairs (salt bridges) of nucleic acid phosphates and protein
side chains are crucial for proteins to bind to DNA or RNA. Counterions
around the macromolecules are also key constituents for the thermodynamics
of protein–nucleic acid association. Until recently, there
had been only a limited amount of experiment-based information about
how ions and ionic moieties behave in biological macromolecular processes.
In the past decade, there has been significant progress in quantitative
experimental research on ionic interactions with nucleic acids and
their complexes with proteins. The highly negatively charged surfaces
of DNA and RNA electrostatically attract and condense cations, creating
a zone called the ion atmosphere. Recent experimental studies were
able to examine and validate theoretical models on ions and their
mobility and interactions with macromolecules. The ionic interactions
are highly dynamic. The counterions rapidly diffuse within the ion
atmosphere. Some of the ions are released from the ion atmosphere
when proteins bind to nucleic acids, balancing the charge via intermolecular
ion pairs of positively charged side chains and negatively charged
backbone phosphates. Previously, the release of counterions had been
implicated indirectly by the salt-concentration dependence of the
association constant. Recently, direct detection of counterion
release by NMR spectroscopy
has become possible and enabled more accurate and quantitative analysis
of the counterion release and its entropic impact on the thermodynamics
of protein–nucleic acid association. Recent studies also revealed
the dynamic nature of ion pairs of protein side chains and nucleic
acid phosphates. These ion pairs undergo transitions between two major
states. In one of the major states, the cation and the anion are in
direct contact and form hydrogen bonds. In the other major state,
the cation and the anion are separated by water. Transitions between
these states rapidly occur on a picosecond to nanosecond time scale.
When proteins interact with nucleic acids, interfacial arginine (Arg)
and lysine (Lys) side chains exhibit considerably different behaviors.
Arg side chains show a higher propensity to form rigid contacts with
nucleotide bases, whereas Lys side chains tend to be more mobile at
the molecular interfaces. The dynamic ionic interactions may facilitate
adaptive molecular recognition and play both thermodynamic and kinetic
roles in protein–nucleic acid interactions.
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Affiliation(s)
- Binhan Yu
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
| | - B. Montgomery Pettitt
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
| | - Junji Iwahara
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
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8
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Nepravishta R, Pletka CC, Iwahara J. Racemic phosphorothioate as a tool for NMR investigations of protein-DNA complexes. JOURNAL OF BIOMOLECULAR NMR 2020; 74:421-429. [PMID: 32683519 PMCID: PMC7511421 DOI: 10.1007/s10858-020-00333-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/09/2020] [Indexed: 05/05/2023]
Abstract
A major driving force for protein-nucleic acid association is electrostatic interactions via ion pairs of the positively charged basic side chains and negatively charged phosphates. For a better understanding of how proteins scan DNA and recognize particular signatures, it is important to gain atomic-level insight into the behavior of basic side chains at the protein-DNA interfaces. NMR spectroscopy is a powerful tool for investigating the structural, dynamic, and kinetic aspects of protein-DNA interactions. However, resonance assignment of basic side-chain cationic moieties at the molecular interfaces remains to be a major challenge. Here, we propose a fast, robust, and inexpensive approach that greatly facilitates resonance assignment of interfacial moieties and also allows for kinetic measurements of protein translocation between two DNA duplexes. This approach utilizes site-specific incorporation of racemic phosphorothioate at the position of a phosphate that interacts with a protein side chain. This modification retains the electric charge of phosphate and therefore is mild, but causes significant chemical shift perturbations for the proximal protein side chains, which facilitates resonance assignment. Due to the racemic nature of the modification, two different chemical shifts are observed for the species with different diastereomers RP and SP of the incorporated phosphorothioate group. Kinetic information on the exchange of the protein molecule between RP and SP DNA duplexes can be obtained by 15Nz exchange spectroscopy. We demonstrate the applications of this approach to the Antennapedia homeodomain-DNA complex and the CREB1 basic leucine-zipper (bZIP)-DNA complex.
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Affiliation(s)
- Ridvan Nepravishta
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, 77555-1068, USA
| | - Channing C Pletka
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, 77555-1068, USA
| | - Junji Iwahara
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, 77555-1068, USA.
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9
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Yamasaki K, Akutsu Y, Yamasaki T, Miyagishi M, Kubota T. Enhanced affinity of racemic phosphorothioate DNA with transcription factor SATB1 arising from diastereomer-specific hydrogen bonds and hydrophobic contacts. Nucleic Acids Res 2020; 48:4551-4561. [PMID: 32187371 PMCID: PMC7192603 DOI: 10.1093/nar/gkaa170] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 02/07/2023] Open
Abstract
Phosphorothioate modification is commonly introduced into therapeutic oligonucleotides, typically as a racemic mixture in which either of the two non-bridging phosphate oxygens is replaced by sulfur, which frequently increases affinities with proteins. Here, we used isothermal titration calorimetry and X-ray crystallography to investigate the thermodynamic and structural properties of the interaction between the primary DNA-binding domain (CUTr1) of transcription factor SATB1 and dodecamer DNAs with racemic phosphorothioate modifications at the six sites known to contact CUTr1 directly. For both the modified and unmodified DNAs, the binding reactions were enthalpy-driven at a moderate salt concentration (50 mM NaCl), while being entropy-driven at higher salt concentrations with reduced affinities. The phosphorothioate modifications lowered this susceptibility to salt, resulting in a significantly enhanced affinity at a higher salt concentration (200 mM NaCl), although only some DNA molecular species remained interacting with CUTr1. This was explained by unequal populations of the two diastereomers in the crystal structure of the complex of CUTr1 and the phosphorothioate-modified DNA. The preferred diastereomer formed more hydrogen bonds with the oxygen atoms and/or more hydrophobic contacts with the sulfur atoms than the other, revealing the origins of the enhanced affinity.
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Affiliation(s)
- Kazuhiko Yamasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan
| | - Yukie Akutsu
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan
| | - Tomoko Yamasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan
| | - Makoto Miyagishi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan
| | - Tomomi Kubota
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan
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10
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Kemme CA, Luu RH, Chen C, Pletka CC, Pettitt BM, Iwahara J. Mobility of Histidine Side Chains Analyzed with 15N NMR Relaxation and Cross-Correlation Data: Insight into Zinc-Finger-DNA Interactions. J Phys Chem B 2019; 123:3706-3710. [PMID: 30963768 DOI: 10.1021/acs.jpcb.9b03132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Due to chemical exchange, the mobility of histidine (His) side chains of proteins is typically difficult to analyze by NMR spectroscopy. Using an NMR approach that is uninfluenced by chemical exchange, we investigated internal motions of the His imidazole NH groups that directly interact with DNA phosphates in the Egr-1 zinc-finger-DNA complex. In this approach, the transverse and longitudinal cross-correlation rates for 15N chemical shift anisotropy and 15N-1H dipole-dipole relaxation interference were analyzed together with 15N longitudinal relaxation rates and heteronuclear Overhauser effect data at two magnetic field strengths. We found that the zinc-coordinating His side chains directly interacting with DNA phosphates are strongly restricted in mobility. This makes a contrast to the arginine and lysine side chains that retain high mobility despite their interactions with DNA phosphates in the same complex. The entropic effects of side-chain mobility on the molecular association are discussed.
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Affiliation(s)
- Catherine A Kemme
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
| | - Ross H Luu
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
| | - Chuanying Chen
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
| | - Channing C Pletka
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
| | - B Montgomery Pettitt
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
| | - Junji Iwahara
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics , University of Texas Medical Branch , Galveston , Texas 77555-1068 , United States
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11
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Structural basis for the recognition of sulfur in phosphorothioated DNA. Nat Commun 2018; 9:4689. [PMID: 30409991 PMCID: PMC6224610 DOI: 10.1038/s41467-018-07093-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 10/12/2018] [Indexed: 12/23/2022] Open
Abstract
There have been very few reports on protein domains that specifically recognize sulfur. Here we present the crystal structure of the sulfur-binding domain (SBD) from the DNA phosphorothioation (PT)-dependent restriction endonuclease ScoMcrA. SBD contains a hydrophobic surface cavity that is formed by the aromatic ring of Y164, the pyrolidine ring of P165, and the non-polar side chains of four other residues that serve as lid, base, and wall of the cavity. The SBD and PT-DNA undergo conformational changes upon binding. The S187RGRR191 loop inserts into the DNA major groove to make contacts with the bases of the GPSGCC core sequence. Mutating key residues of SBD impairs PT-DNA association. More than 1000 sequenced microbial species from fourteen phyla contain SBD homologs. We show that three of these homologs bind PT-DNA in vitro and restrict PT-DNA gene transfer in vivo. These results show that SBD-like PT-DNA readers exist widely in prokaryotes.
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12
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Nguyen D, Chen C, Pettitt BM, Iwahara J. NMR Methods for Characterizing the Basic Side Chains of Proteins: Electrostatic Interactions, Hydrogen Bonds, and Conformational Dynamics. Methods Enzymol 2018; 615:285-332. [PMID: 30638532 DOI: 10.1016/bs.mie.2018.08.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
NMR spectroscopy is a powerful tool for studying protein dynamics. Conventionally, NMR studies on protein dynamics have probed motions of protein backbone NH, side-chain aromatic, and CH3 groups. Recently, there has been remarkable progress in NMR methodologies that can characterize motions of cationic groups in protein side chains. These NMR methods allow investigations of the dynamics of positively charged lysine (Lys) and arginine (Arg) side chains and their hydrogen bonds as well as their electrostatic interactions important for protein function. Here, describing various practical aspects, we provide an overview of the NMR methods for dynamics studies of Lys and Arg side chains. Some example data on protein-DNA complexes are shown. We will also explain how molecular dynamics (MD) simulations can facilitate the interpretation of the NMR data on these basic side chains. Studies combining NMR and MD have revealed the highly dynamic nature of short-range electrostatic interactions via ion pairs, especially those involving Lys side chains.
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Affiliation(s)
- Dan Nguyen
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
| | - Chuanying Chen
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
| | - B Montgomery Pettitt
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
| | - Junji Iwahara
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States.
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Nguyen D, Hoffpauir ZA, Iwahara J. Internal Motions of Basic Side Chains of the Antennapedia Homeodomain in the Free and DNA-Bound States. Biochemistry 2017; 56:5866-5869. [PMID: 29045141 PMCID: PMC5682595 DOI: 10.1021/acs.biochem.7b00885] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Basic side chains play crucial roles in protein-DNA interactions. In this study, using NMR spectroscopy, we investigated the dynamics of Arg and Lys side chains of the fruit fly Antennapedia homeodomain in the free state and in the complex with target DNA. We measured 15N relaxation for Arg and Lys side chains at two magnetic fields, from which generalized order parameters for the cationic groups were determined. Mobility of the R5 side chain, which makes hydrogen bonds with a thymine base in the DNA minor groove, was greatly dampened. Several Lys and Arg side chains that form intermolecular ion pairs with DNA phosphates were found to retain high mobility with the order parameter being <0.6 in the DNA-bound state. Interestingly, some of the interfacial cationic groups in the complex were more mobile than in the free protein. The retained or enhanced mobility of the Arg and Lys side chains in the complex should mitigate the overall loss of conformational entropy in the protein-DNA association and allow dynamic molecular recognition.
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Affiliation(s)
- Dan Nguyen
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Zoe A. Hoffpauir
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Junji Iwahara
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
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Nguyen D, Lokesh GLR, Volk DE, Iwahara J. A Unique and Simple Approach to Improve Sensitivity in 15N-NMR Relaxation Measurements for NH₃⁺ Groups: Application to a Protein-DNA Complex. Molecules 2017; 22:molecules22081355. [PMID: 28809801 PMCID: PMC5602601 DOI: 10.3390/molecules22081355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 08/11/2017] [Accepted: 08/11/2017] [Indexed: 11/16/2022] Open
Abstract
NMR spectroscopy is a powerful tool for research on protein dynamics. In the past decade, there has been significant progress in the development of NMR methods for studying charged side chains. In particular, NMR methods for lysine side-chain NH₃⁺ groups have been proven to be powerful for investigating the dynamics of hydrogen bonds or ion pairs that play important roles in biological processes. However, relatively low sensitivity has been a major practical issue in NMR experiments on NH₃⁺ groups. In this paper, we present a unique and simple approach to improve sensitivity in 15N relaxation measurements for NH₃⁺ groups. In this approach, the efficiency of coherence transfers for the desired components are maximized, whereas undesired anti-phase or multi-spin order components are purged through pulse schemes and rapid relaxation. For lysine side-chain NH₃⁺ groups of a protein-DNA complex, we compared the data obtained with the previous and new pulse sequences under the same conditions and confirmed that the 15N relaxation parameters were consistent for these datasets. While retaining accuracy in measuring 15N relaxation, our new pulse sequences for NH₃⁺ groups allowed an 82% increase in detection sensitivity of 15N longitudinal and transverse relaxation measurements.
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Affiliation(s)
- Dan Nguyen
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Ganesh L R Lokesh
- McGovern Medical School, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas Health Science Center, Houston, TX 77030, USA.
| | - David E Volk
- McGovern Medical School, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas Health Science Center, Houston, TX 77030, USA.
| | - Junji Iwahara
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
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