1
|
Cai M, Agarwal N, Garrett DS, Baber J, Clore GM. A Transient, Excited Species of the Autoinhibited α-State of the Bacterial Transcription Factor RfaH May Represent an Early Intermediate on the Fold-Switching Pathway. Biochemistry 2024; 63:2030-2039. [PMID: 39088556 PMCID: PMC11345854 DOI: 10.1021/acs.biochem.4c00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
RfaH is a two-domain transcription factor in which the C-terminal domain switches fold from an α-helical hairpin to a β-roll upon binding the ops-paused RNA polymerase. To ascertain the presence of a sparsely populated excited state that may prime the autoinhibited resting state of RfaH for binding ops-paused RNA polymerase, we carried out a series of NMR-based exchange experiments to probe for conformational exchange on the millisecond time scale. Quantitative analysis of these data reveals exchange between major ground (∼95%) and sparsely populated excited (∼5%) states with an exchange lifetime of ∼3 ms involving residues at the interface between the N-terminal and C-terminal domains formed by the β3/β4 hairpin and helix α3 of the N-terminal domain and helices α4 and α5 of the C-terminal domain. The largest 15N backbone chemical shift differences are associated with the β3/β4 hairpin, leading us to suggest that the excited state may involve a rigid body lateral displacement/rotation away from the C-terminal domain to adopt a position similar to that seen in the active RNA polymerase-bound state. Such a rigid body reorientation would result in a reduction in the interface between the N- and C-terminal domains with the possible introduction of a cavity or cavities. This hypothesis is supported by the observation that the population of the excited species and the exchange rate of interconversion between ground and excited states are reduced at a high (2.5 kbar) pressure. Mechanistic implications for fold switching of the C-terminal domain in the context of RNA polymerase binding are discussed.
Collapse
Affiliation(s)
- Mengli Cai
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Nipanshu Agarwal
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Daniel S. Garrett
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - James Baber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| |
Collapse
|
2
|
Kalaj BN, La Clair JJ, Shen Y, Schwieters CD, Deshmukh L, Burkart MD. Quantitative Characterization of Chain-Flipping of Acyl Carrier Protein of Escherichia coli Using Chemical Exchange NMR. J Am Chem Soc 2024; 146:18650-18660. [PMID: 38875499 PMCID: PMC11299499 DOI: 10.1021/jacs.4c05509] [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] [Indexed: 06/16/2024]
Abstract
The acyl carrier protein of Escherichia coli, termed AcpP, is a prototypical example of type II fatty acid synthase systems found in many bacteria. It serves as a central hub by accepting diverse acyl moieties (4-18 carbons) and shuttling them between its multiple enzymatic partners to generate fatty acids. Prior structures of acyl-AcpPs established that thioester-linked acyl cargos are sequestered within AcpP's hydrophobic lumen. In contrast, structures of enzyme-bound acyl-AcpPs showed translocation of AcpP-tethered acyl chains into the active sites of enzymes. The mechanistic underpinnings of this conformational interplay, termed chain-flipping, are unclear. Here, using heteronuclear NMR spectroscopy, we reveal that AcpP-tethered acyl chains (6-10 carbons) spontaneously adopt lowly populated solvent-exposed conformations. To this end, we devised a new strategy to replace AcpP's thioester linkages with 15N-labeled amide bonds, which facilitated direct "visualization" of these excited states using NMR chemical exchange saturation transfer and relaxation dispersion measurements. Global fitting of the corresponding data yielded kinetic rate constants of the underlying equilibrium and populations and lifetimes of solvent-exposed states. The latter were influenced by acyl chain composition and ranged from milliseconds to submilliseconds for chains containing six, eight, and ten carbons, owing to their variable interactions with AcpP's hydrophobic core. Although transient, the exposure of AcpP-tethered acyl chains to the solvent may allow relevant enzymes to gain access to its active thioester, and the enzyme-induced selection of this conformation will culminate in the production of fatty acids.
Collapse
Affiliation(s)
- Brianna N. Kalaj
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - James J. La Clair
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Charles D. Schwieters
- Computational Biomolecular Magnetic Resonance Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
3
|
Robello M, Nikolayevskiy H, Scerba MT, Nahui Palomino RA, Mercurio V, Appella DH. Prodrug Strategy Extends the Use of Anti-HIV Sulfanylbenzamides for Application In Vivo. ACS Pharmacol Transl Sci 2024; 7:259-273. [PMID: 38250006 PMCID: PMC10795369 DOI: 10.1021/acsptsci.3c00260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 01/23/2024]
Abstract
Sulfanylbenzamide thioesters are molecules with anti-HIV activity that disrupt zinc coordination in the viral protein NCp7. These molecules are useful as topical microbicides; however, they are too unstable to be used systemically. In this article, a nitroimidazole prodrug was used to protect the sulfanylbenzamide to convey blood stability and oral bioavailability to the molecule. Studies on the molecule called nipamovir were performed to assess the rate of prodrug cleavage, antiviral activity, mechanism of metabolism, and in vivo pharmacokinetics in several different species. An efficient and inexpensive synthesis of nipamovir is also described. The results indicate that nipamovir could be further developed as a new type of drug to treat HIV infection.
Collapse
Affiliation(s)
- Marco Robello
- Synthetic Bioactive Molecules Section, Laboratory of
Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center
Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Herman Nikolayevskiy
- Synthetic Bioactive Molecules Section, Laboratory of
Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center
Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Michael T. Scerba
- Synthetic Bioactive Molecules Section, Laboratory of
Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center
Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Rogers Alberto Nahui Palomino
- Section on Intercellular Interactions, Eunice Kennedy
Shriver National Institute of Child Health and Human Development, National
Institutes of Health, Bethesda, Maryland 20892, United
States
| | - Vincenzo Mercurio
- Section on Intercellular Interactions, Eunice Kennedy
Shriver National Institute of Child Health and Human Development, National
Institutes of Health, Bethesda, Maryland 20892, United
States
| | - Daniel H. Appella
- Synthetic Bioactive Molecules Section, Laboratory of
Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center
Drive, Room 404, Bethesda, Maryland 20892, United States
| |
Collapse
|
4
|
Bregnard TA, Fairchild D, Erlandsen H, Semenova IV, Szczepaniak R, Ahmed A, Weller SK, Korzhnev DM, Bezsonova I. Conformational exchange at a C 2H 2 zinc-binding site facilitates redox sensing by the PML protein. Structure 2023; 31:1086-1099.e6. [PMID: 37473756 PMCID: PMC10528520 DOI: 10.1016/j.str.2023.06.014] [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: 12/20/2022] [Revised: 05/12/2023] [Accepted: 06/23/2023] [Indexed: 07/22/2023]
Abstract
The promyelocytic leukemia protein, PML, plays a vital role in the cellular response to oxidative stress; however, the molecular mechanism of its action remains poorly understood. Here, we identify redox-sensitive sites of PML. A molecule of PML is cysteine-rich and contains three zinc-binding domains including RING, B-box1, and B-box2. Using in vitro assays, we have compared the sensitivity of the isolated RING and B-box1 domains and shown that B-box1 is more sensitive to oxidation. NMR studies of PML dynamics showed that one of the Zn-coordination sites within the B-box1 undergoes significant conformational exchange, revealing a hotspot for exposure of reactive cysteines. In agreement with the in vitro data, enhancement of the B-box1 Zn-coordination dynamics led to more efficient recruitment of PML into PML nuclear bodies in cells. Overall, our results suggest that the increased sensitivity of B-box1 to oxidative stress makes this domain an important redox-sensing component of PML.
Collapse
Affiliation(s)
- Thomas A Bregnard
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Daniel Fairchild
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Heidi Erlandsen
- Center for Open Research Resources & Equipment, UCONN, Storrs, CT 06269, USA
| | - Irina V Semenova
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Renata Szczepaniak
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Affrin Ahmed
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Sandra K Weller
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Dmitry M Korzhnev
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UCONN Health, Farmington, CT 06032, USA.
| |
Collapse
|
5
|
Cardia R, Cappellini G, Valentini M, Pieroni E. A combined molecular dynamics simulation and DFT study on mercapto-benzamide inhibitors for the HIV NCp7 protein. Phys Chem Chem Phys 2022; 24:25547-25554. [PMID: 36254678 DOI: 10.1039/d2cp03481f] [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: 06/16/2023]
Abstract
Molecular dynamics and quantum simulations are performed to elucidate some aspects of the action mechanism of mercapto-benzamides, a proposed class of antivirals against HIV-1. These molecules act as prodrugs that, after modifications in the biological environment, are able to denature the HIV nucleocapsid protein 7, a metal binder protein, with two zinc finger motifs, vital for RNA maturation and viral replication. Despite their attractive features, these molecules and their biological target are not well understood. Simulations were performed to support a proposed action mechanism, based on the activation of mercapto-benzamides by acetylation, targeting a relatively rare protein hydrolyzed state, followed by trans-molecular acetylation from the molecule to the protein and finally the direct interaction of the molecular sulphur atom of mercapto-benzamides with the zinc atom coordinated by the protein. Our simulation results are in agreement with the NMR data about the zinc finger binding protein equilibrium configurations.
Collapse
Affiliation(s)
- R Cardia
- Dipartimento di Fisica, Università di Cagliari, 09042, Cagliari, Italy
- CRS4, Modelling, Simulation and Data Analysis Program, 09010, Pula, Italy.
| | - G Cappellini
- Dipartimento di Fisica, Università di Cagliari, 09042, Cagliari, Italy
- ETSF, European Theoretical Spectroscopy Facility, Italy
| | - M Valentini
- CRS4, Modelling, Simulation and Data Analysis Program, 09010, Pula, Italy.
| | - E Pieroni
- CRS4, Modelling, Simulation and Data Analysis Program, 09010, Pula, Italy.
| |
Collapse
|
6
|
Investigation of the Low-Populated Excited States of the HIV-1 Nucleocapsid Domain. Viruses 2022; 14:v14030632. [PMID: 35337039 PMCID: PMC8950434 DOI: 10.3390/v14030632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/07/2022] [Accepted: 03/16/2022] [Indexed: 12/10/2022] Open
Abstract
The nucleocapsid domain (NCd), located at the C-terminus of the HIV-1 Gag protein, is involved in numerous stages of the replication cycle, such as the packaging of the viral genome and reverse transcription. It exists under different forms through the viral life cycle, depending on the processing of Gag by the HIV-1 protease. NCd is constituted of two adjacent zinc knuckles (ZK1 and ZK2), separated by a flexible linker and flanked by disordered regions. Here, conformational equilibria between a major and two minor states were highlighted exclusively in ZK2, by using CPMG and CEST NMR experiments. These minor states appear to be temperature dependent, and their populations are highest at physiological temperature. These minor states are present both in NCp7, the mature form of NCd, and in NCp9 and NCp15, the precursor forms of NCd, with increased populations. The role of these minor states in the targeting of NCd by drugs and its binding properties is discussed.
Collapse
|
7
|
Tugarinov V, Ceccon A, Clore GM. NMR methods for exploring 'dark' states in ligand binding and protein-protein interactions. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 128:1-24. [PMID: 35282867 PMCID: PMC8921508 DOI: 10.1016/j.pnmrs.2021.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/21/2021] [Accepted: 10/26/2021] [Indexed: 05/24/2023]
Abstract
A survey, primarily based on work in the authors' laboratory during the last 10 years, is provided of recent developments in NMR studies of exchange processes involving protein-ligand and protein-protein interactions. We start with a brief overview of the theoretical background of Dark state Exchange Saturation Transfer (DEST) and lifetime line-broadening (ΔR2) NMR methodology. Some limitations of the DEST/ΔR2 methodology in applications to molecular systems with intermediate molecular weights are discussed, along with the means of overcoming these limitations with the help of closely related exchange NMR techniques, such as the measurements of Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion, exchange-induced chemical shifts or rapidly-relaxing components of relaxation decays. Some theoretical underpinnings of the quantitative description of global dynamics of proteins on the surface of very high molecular weight particles (nanoparticles) are discussed. Subsequently, several applications of DEST/ΔR2 methodology are described from a methodological perspective with an emphasis on providing examples of how kinetic and relaxation parameters for exchanging systems can be reliably extracted from NMR data for each particular model of exchange. Among exchanging systems that are not associated with high molecular weight species, we describe several exchange NMR-based studies that focus on kinetic modelling of transient pre-nucleation oligomerization of huntingtin peptides that precedes aggregation and fibril formation.
Collapse
Affiliation(s)
- Vitali Tugarinov
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States.
| | - Alberto Ceccon
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States.
| |
Collapse
|
8
|
The A39G FF domain folds on a volcano-shaped free energy surface via separate pathways. Proc Natl Acad Sci U S A 2021; 118:2115113118. [PMID: 34764225 DOI: 10.1073/pnas.2115113118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2021] [Indexed: 11/18/2022] Open
Abstract
Conformational dynamics play critical roles in protein folding, misfolding, function, misfunction, and aggregation. While detecting and studying the different conformational states populated by protein molecules on their free energy surfaces (FESs) remain a challenge, NMR spectroscopy has emerged as an invaluable experimental tool to explore the FES of a protein, as conformational dynamics can be probed at atomic resolution over a wide range of timescales. Here, we use chemical exchange saturation transfer (CEST) to detect "invisible" minor states on the energy landscape of the A39G mutant FF domain that exhibited "two-state" folding kinetics in traditional experiments. Although CEST has mostly been limited to studies of processes with rates between ∼5 to 300 s-1 involving sparse states with populations as low as ∼1%, we show that the line broadening that is often associated with minor state dips in CEST profiles can be exploited to inform on additional conformers, with lifetimes an order of magnitude shorter and populations close to 10-fold smaller than what typically is characterized. Our analysis of CEST profiles that exploits the minor state linewidths of the 71-residue A39G FF domain establishes a folding mechanism that can be described in terms of a four-state exchange process between interconverting states spanning over two orders of magnitude in timescale from ∼100 to ∼15,000 μs. A similar folding scheme is established for the wild-type domain as well. The study shows that the folding of this small domain proceeds through a pair of sparse, partially structured intermediates via two discrete pathways on a volcano-shaped FES.
Collapse
|
9
|
Wang Y, Guo C, Wang X, Xu L, Li R, Wang J. The Zinc Content of HIV-1 NCp7 Affects Its Selectivity for Packaging Signal and Affinity for Stem-Loop 3. Viruses 2021; 13:v13101922. [PMID: 34696351 PMCID: PMC8540335 DOI: 10.3390/v13101922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022] Open
Abstract
The nucleocapsid (NC) protein of human immunodeficiency (HIV) is a small, highly basic protein containing two CCHC zinc-finger motifs, which is cleaved from the NC domain of the Gag polyprotein during virus maturation. We previously reported that recombinant HIV-1 Gag and NCp7 overexpressed in an E. coli host contains two and one zinc ions, respectively, and Gag exhibited much higher selectivity for packaging signal (Psi) and affinity for the stem-loop (SL)-3 of Psi than NCp7. In this study, we prepared NCp7 containing 0 (0NCp7), 1 (NCp7) or 2 (2NCp7) zinc ions, and compared their secondary structure, Psi-selectivity and SL3-affinity. Along with the decrease of the zinc content, less ordered conformations were detected. Compared to NCp7, 2NCp7 exhibited a much higher Psi-selectivity and SL3-affinity, similar to Gag, whereas 0NCp7 exhibited a lower Psi-selectivity and SL3-affinity, similar to the H23&H44K double mutant of NCp7, indicating that the different RNA-binding property of Gag NC domain and the mature NCp7 may be resulted, at least partially, from their different zinc content. This study will be helpful to elucidate the critical roles that zinc played in the viral life cycle, and benefit further investigations of the functional switch from the NC domain of Gag to the mature NCp7.
Collapse
Affiliation(s)
- Ying Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; (Y.W.); (X.W.); (L.X.); (R.L.)
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Chao Guo
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan 030001, China;
| | - Xing Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; (Y.W.); (X.W.); (L.X.); (R.L.)
| | - Lianmei Xu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; (Y.W.); (X.W.); (L.X.); (R.L.)
| | - Rui Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; (Y.W.); (X.W.); (L.X.); (R.L.)
| | - Jinzhong Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; (Y.W.); (X.W.); (L.X.); (R.L.)
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
- Correspondence:
| |
Collapse
|
10
|
Jaladeep A, Varghese CN, Sekhar A. Measuring radiofrequency fields in NMR spectroscopy using offset-dependent nutation profiles. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 330:107032. [PMID: 34311422 PMCID: PMC7612739 DOI: 10.1016/j.jmr.2021.107032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 06/13/2023]
Abstract
The application of NMR spectroscopy for studying molecular and reaction dynamics relies crucially on the measurement of the magnitude of radiofrequency (RF) fields that are used to nutate or lock the nuclear magnetization. Here, we report a method for measuring RF field amplitudes that leverages the intrinsic modulations observed in offset-dependent NMR nutation profiles of small molecules. Such nutation profiles are exquisitely sensitive to the magnitude of the RF field, and B1 values ranging from 1 to 2000 Hz, as well the inhomogeneity in B1 distributions, can be determined with high accuracy and precision using this approach. In order to measure B1 fields associated with NMR experiments carried out on protein or nucleic acids, where these modulations are obscured by the large transverse relaxation rate constants of the analyte, our approach can be used in conjunction with a suitable external small molecule standard, expanding the scope of the method for large biomolecules.
Collapse
Affiliation(s)
- Ahallya Jaladeep
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Claris Niya Varghese
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.
| |
Collapse
|
11
|
Wang R, Wei Y, Wang M, Yan P, Jiang H, Du Z. Interaction of Natural Compounds in Licorice and Turmeric with HIV-NCp7 Zinc Finger Domain: Potential Relevance to the Mechanism of Antiviral Activity. Molecules 2021; 26:molecules26123563. [PMID: 34200973 PMCID: PMC8230585 DOI: 10.3390/molecules26123563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/28/2021] [Accepted: 06/09/2021] [Indexed: 01/10/2023] Open
Abstract
Nucleocapsid proteins (NCp) are zinc finger (ZF) proteins, and they play a central role in HIV virus replication, mainly by interacting with nucleic acids. Therefore, they are potential targets for anti-HIV therapy. Natural products have been shown to be able to inhibit HIV, such as turmeric and licorice, which is widely used in traditional Chinese medicine. Liquiritin (LQ), isoliquiritin (ILQ), glycyrrhizic acid (GL), glycyrrhetinic acid (GA) and curcumin (CUR), which were the major active components, were herein chosen to study their interactions with HIV-NCp7 C-terminal zinc finger, aiming to find the potential active compounds and reveal the mechanism involved. The stacking interaction between NCp7 tryptophan and natural compounds was evaluated by fluorescence. To elucidate the binding mode, mass spectrometry was used to characterize the reaction mixture between zinc finger proteins and active compounds. Subsequently, circular dichroism (CD) spectroscopy and molecular docking were used to validate and reveal the binding mode from a structural perspective. The results showed that ILQ has the strongest binding ability among the tested compounds, followed by curcumin, and the interaction between ILQ and the NCp7 zinc finger peptide was mediated by a noncovalent interaction. This study provided a scientific basis for the antiviral activity of turmeric and licorice.
Collapse
Affiliation(s)
- Runjing Wang
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
- Ningxia Pharmaceutical Inspection and Research Institute, Yinchuan 750001, China
| | - Yinyu Wei
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
| | - Meiqin Wang
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
| | - Pan Yan
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
| | - Hongliang Jiang
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
| | - Zhifeng Du
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China; (R.W.); (Y.W.); (M.W.); (P.Y.); (H.J.)
- Correspondence:
| |
Collapse
|
12
|
Agarwal PK, Bernard DN, Bafna K, Doucet N. Enzyme dynamics: Looking beyond a single structure. ChemCatChem 2020; 12:4704-4720. [PMID: 33897908 PMCID: PMC8064270 DOI: 10.1002/cctc.202000665] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Indexed: 12/23/2022]
Abstract
Conventional understanding of how enzymes function strongly emphasizes the role of structure. However, increasing evidence clearly indicates that enzymes do not remain fixed or operate exclusively in or close to their native structure. Different parts of the enzyme (from individual residues to full domains) undergo concerted motions on a wide range of time-scales, including that of the catalyzed reaction. Information obtained on these internal motions and conformational fluctuations has so far uncovered and explained many aspects of enzyme mechanisms, which could not have been understood from a single structure alone. Although there is wide interest in understanding enzyme dynamics and its role in catalysis, several challenges remain. In addition to technical difficulties, the vast majority of investigations are performed in dilute aqueous solutions, where conditions are significantly different than the cellular milieu where a large number of enzymes operate. In this review, we discuss recent developments, several challenges as well as opportunities related to this topic. The benefits of considering dynamics as an integral part of the enzyme function can also enable new means of biocatalysis, engineering enzymes for industrial and medicinal applications.
Collapse
Affiliation(s)
- Pratul K. Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma 74078
- Arium BioLabs, 2519 Caspian Drive, Knoxville, Tennessee 37932
| | - David N. Bernard
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada
| | - Khushboo Bafna
- Department of Chemistry and Chemical Biology, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - Nicolas Doucet
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Structure, and Engineering, 1045 Avenue de la Médecine, Université Laval, Québec, QC, G1V 0A6, Canada
| |
Collapse
|
13
|
Boyd PS, Brown JB, Brown JD, Catazaro J, Chaudry I, Ding P, Dong X, Marchant J, O’Hern CT, Singh K, Swanson C, Summers MF, Yasin S. NMR Studies of Retroviral Genome Packaging. Viruses 2020; 12:v12101115. [PMID: 33008123 PMCID: PMC7599994 DOI: 10.3390/v12101115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/18/2020] [Accepted: 09/26/2020] [Indexed: 12/03/2022] Open
Abstract
Nearly all retroviruses selectively package two copies of their unspliced RNA genomes from a cellular milieu that contains a substantial excess of non-viral and spliced viral RNAs. Over the past four decades, combinations of genetic experiments, phylogenetic analyses, nucleotide accessibility mapping, in silico RNA structure predictions, and biophysical experiments were employed to understand how retroviral genomes are selected for packaging. Genetic studies provided early clues regarding the protein and RNA elements required for packaging, and nucleotide accessibility mapping experiments provided insights into the secondary structures of functionally important elements in the genome. Three-dimensional structural determinants of packaging were primarily derived by nuclear magnetic resonance (NMR) spectroscopy. A key advantage of NMR, relative to other methods for determining biomolecular structure (such as X-ray crystallography), is that it is well suited for studies of conformationally dynamic and heterogeneous systems—a hallmark of the retrovirus packaging machinery. Here, we review advances in understanding of the structures, dynamics, and interactions of the proteins and RNA elements involved in retroviral genome selection and packaging that are facilitated by NMR.
Collapse
|
14
|
Elias RD, Ma W, Ghirlando R, Schwieters CD, Reddy VS, Deshmukh L. Proline-rich domain of human ALIX contains multiple TSG101-UEV interaction sites and forms phosphorylation-mediated reversible amyloids. Proc Natl Acad Sci U S A 2020; 117:24274-24284. [PMID: 32917811 PMCID: PMC7533887 DOI: 10.1073/pnas.2010635117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Proline-rich domains (PRDs) are among the most prevalent signaling modules of eukaryotes but often unexplored by biophysical techniques as their heterologous recombinant expression poses significant difficulties. Using a "divide-and-conquer" approach, we present a detailed investigation of a PRD (166 residues; ∼30% prolines) belonging to a human protein ALIX, a versatile adaptor protein involved in essential cellular processes including ESCRT-mediated membrane remodeling, cell adhesion, and apoptosis. In solution, the N-terminal fragment of ALIX-PRD is dynamically disordered. It contains three tandem sequentially similar proline-rich motifs that compete for a single binding site on its signaling partner, TSG101-UEV, as evidenced by heteronuclear NMR spectroscopy. Global fitting of relaxation dispersion data, measured as a function of TSG101-UEV concentration, allowed precise quantitation of these interactions. In contrast to the soluble N-terminal portion, the C-terminal tyrosine-rich fragment of ALIX-PRD forms amyloid fibrils and viscous gels validated using dye-binding assays with amyloid-specific probes, congo red and thioflavin T (ThT), and visualized by transmission electron microscopy. Remarkably, fibrils dissolve at low temperatures (2 to 6 °C) or upon hyperphosphorylation with Src kinase. Aggregation kinetics monitored by ThT fluorescence shows that charge repulsion dictates phosphorylation-mediated fibril dissolution and that the hydrophobic effect drives fibril formation. These data illuminate the mechanistic interplay between interactions of ALIX-PRD with TSG101-UEV and polymerization of ALIX-PRD and its central role in regulating ALIX function. This study also demonstrates the broad functional repertoires of PRDs and uncovers the impact of posttranslational modifications in the modulation of reversible amyloids.
Collapse
Affiliation(s)
- Ruben D Elias
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Wen Ma
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Charles D Schwieters
- Division of Computational Biosciences, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892
| | - Vijay S Reddy
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093;
| |
Collapse
|
15
|
Mouhand A, Pasi M, Catala M, Zargarian L, Belfetmi A, Barraud P, Mauffret O, Tisné C. Overview of the Nucleic-Acid Binding Properties of the HIV-1 Nucleocapsid Protein in Its Different Maturation States. Viruses 2020; 12:v12101109. [PMID: 33003650 PMCID: PMC7601788 DOI: 10.3390/v12101109] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 12/17/2022] Open
Abstract
HIV-1 Gag polyprotein orchestrates the assembly of viral particles. Its C-terminus consists of the nucleocapsid (NC) domain that interacts with nucleic acids, and p1 and p6, two unstructured regions, p6 containing the motifs to bind ALIX, the cellular ESCRT factor TSG101 and the viral protein Vpr. The processing of Gag by the viral protease subsequently liberates NCp15 (NC-p1-p6), NCp9 (NC-p1) and NCp7, NCp7 displaying the optimal chaperone activity of nucleic acids. This review focuses on the nucleic acid binding properties of the NC domain in the different maturation states during the HIV-1 viral cycle.
Collapse
Affiliation(s)
- Assia Mouhand
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Marco Pasi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Marjorie Catala
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Loussiné Zargarian
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Anissa Belfetmi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Pierre Barraud
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Olivier Mauffret
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
- Correspondence: (O.M.); (C.T.)
| | - Carine Tisné
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
- Correspondence: (O.M.); (C.T.)
| |
Collapse
|
16
|
Tiwari VP, Vallurupalli P. A CEST NMR experiment to obtain glycine 1H α chemical shifts in 'invisible' minor states of proteins. JOURNAL OF BIOMOLECULAR NMR 2020; 74:443-455. [PMID: 32696193 DOI: 10.1007/s10858-020-00336-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/11/2020] [Indexed: 06/11/2023]
Abstract
Chemical exchange saturation transfer (CEST) experiments are routinely used to study protein conformational exchange between a 'visible' major state and 'invisible' minor states because they can detect minor states with lifetimes varying from ~ 3 to ~ 100 ms populated to just ~ 0.5%. Consequently several 1H, 15N and 13C CEST experiments have been developed to study exchange and obtain minor state chemical shifts at almost all backbone and sidechain sites in proteins. Conspicuously missing from this extensive set of CEST experiments is a 1H CEST experiment to study exchange at glycine (Gly) 1Hα sites as the existing 1H CEST experiments that have been designed to study dynamics in amide 1H-15N spin systems and methyl 13CH3 groups with three equivalent protons while suppressing 1H-1H NOE induced dips are not suitable for studying exchange in methylene 13CH2 groups with inequivalent protons. Here a Gly 1Hα CEST experiment to obtain the minor state Gly 1Hα chemical shifts is presented. The utility of this experiment is demonstrated on the L99A cavity mutant of T4 Lysozyme (T4L L99A) that undergoes conformational exchange between two compact conformers. The CEST derived minor state Gly 1Hα chemical shifts of T4L L99A are in agreement with those obtained previously using CPMG techniques. The experimental strategy presented here can also be used to obtain methylene proton minor state chemical shifts from protein sidechain and nucleic acid backbone sites.
Collapse
Affiliation(s)
- Ved Prakash Tiwari
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India.
| |
Collapse
|
17
|
Nikolayevskiy H, Robello M, Scerba MT, Pasternak EH, Saha M, Hartman TL, Buchholz CA, Buckheit RW, Durell SR, Appella DH. The structure-activity profile of mercaptobenzamides' anti-HIV activity suggests that thermodynamics of metabolism is more important than binding affinity to the target. Eur J Med Chem 2019; 178:818-837. [PMID: 31252286 PMCID: PMC8132308 DOI: 10.1016/j.ejmech.2019.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/07/2019] [Accepted: 06/07/2019] [Indexed: 01/06/2023]
Abstract
Mercaptobenzamide thioesters and thioethers are chemically simple HIV-1 maturation inhibitors with a unique mechanism of action, low toxicity, and a high barrier to viral resistance. A structure-activity relationship (SAR) profile based on 39 mercaptobenzamide prodrug analogs exposed divergent activity/toxicity roles for the internal and terminal amides. To probe the relationship between antiviral activity and toxicity, we generated an improved computational model for the binding of mercaptobenzamide thioesters (SAMTs) to the HIV-1 NCp7 C-terminal zinc finger, revealing the presence of a second low-energy binding orientation, hitherto undisclosed. Finally, using NMR-derived thiol-thioester exchange equilibrium constants, we propose that thermodynamics plays a role in determining the antiviral activity observed in the SAR profile.
Collapse
Affiliation(s)
- Herman Nikolayevskiy
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Marco Robello
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Michael T Scerba
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Evan H Pasternak
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Mrinmoy Saha
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Tracy L Hartman
- ImQuest Biosciences, 7340 Executive Way, Suite R, Frederick, MD, 21704, USA
| | - Caitlin A Buchholz
- ImQuest Biosciences, 7340 Executive Way, Suite R, Frederick, MD, 21704, USA
| | - Robert W Buckheit
- ImQuest Biosciences, 7340 Executive Way, Suite R, Frederick, MD, 21704, USA
| | - Stewart R Durell
- Laboratory of Cell Biology, NCI, NIH, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Daniel H Appella
- Synthetic Bioactive Molecules Section, LBC, NIDDK, NIH, 8 Center Drive, Room 404, Bethesda, MD, 20892, USA.
| |
Collapse
|
18
|
Vallurupalli P, Tiwari VP, Ghosh S. A Double-Resonance CEST Experiment To Study Multistate Protein Conformational Exchange: An Application to Protein Folding. J Phys Chem Lett 2019; 10:3051-3056. [PMID: 31081645 DOI: 10.1021/acs.jpclett.9b00985] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Despite the importance of protein dynamics to function, studying exchange between multiple conformational states remains a challenge because sparsely populated states are invisible to conventional techniques. CEST NMR experiments can detect minor states with lifetimes between 5 and 200 ms populated to a level of just ∼1%. However, CEST often cannot provide the exchange mechanism for processes involving three or more states, leaving the role of the detected minor states unknown. Here a double-resonance CEST experiment to determine the kinetics of multistate exchange is presented. The approach that involves irradiating resonances from two minor states simultaneously is used to study the exchange of T4 lysozyme (T4L) between the dominant native state and two minor states, the unfolded state and a second minor state (B), each populated to only ∼4%. Regular CEST does not provide the folding mechanism, but double-resonance CEST clearly shows that T4L can fold directly without going through B.
Collapse
Affiliation(s)
- Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
| | - Ved Prakash Tiwari
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
| | - Shamasree Ghosh
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
| |
Collapse
|
19
|
Miller Jenkins LM, Paine EL, Deshmukh L, Nikolayevskiy H, Lyons GC, Scerba MT, Rosenker KG, Luecke HF, Louis JM, Chertova E, Gorelick RJ, Ott DE, Clore GM, Appella DH. Inhibition of HIV Maturation via Selective Unfolding and Cross-Linking of Gag Polyprotein by a Mercaptobenzamide Acetylator. J Am Chem Soc 2019; 141:8327-8338. [PMID: 31042030 PMCID: PMC8496520 DOI: 10.1021/jacs.9b02743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For HIV to become infectious, any new virion produced from an infected cell must undergo a maturation process that involves the assembly of viral polyproteins Gag and Gag-Pol at the membrane surface. The self-assembly of these viral proteins drives formation of a new viral particle as well as the activation of HIV protease, which is needed to cleave the polyproteins so that the final core structure of the virus will properly form. Molecules that interfere with HIV maturation will prevent any new virions from infecting additional cells. In this manuscript, we characterize the unique mechanism by which a mercaptobenzamide thioester small molecule (SAMT-247) interferes with HIV maturation via a series of selective acetylations at highly conserved cysteine and lysine residues in Gag and Gag-Pol polyproteins. The results provide the first insights into how acetylation can be utilized to perturb the process of HIV maturation and reveal a new strategy to limit the infectivity of HIV.
Collapse
Affiliation(s)
- Lisa M. Miller Jenkins
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Elliott L. Paine
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Lalit Deshmukh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Herman Nikolayevskiy
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Gaelyn C. Lyons
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Michael T. Scerba
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Kara George Rosenker
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Hans F. Luecke
- Advanced Mass Spectrometry Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - David E. Ott
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Daniel H. Appella
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| |
Collapse
|
20
|
Tiwari VP, Pandit S, Vallurupalli P. Exchangeable deuterons introduce artifacts in amide 15N CEST experiments used to study protein conformational exchange. JOURNAL OF BIOMOLECULAR NMR 2019; 73:43-48. [PMID: 30661150 DOI: 10.1007/s10858-018-00223-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/27/2018] [Indexed: 06/09/2023]
Abstract
Protein molecules sample different conformations in solution and characterizing these conformations is crucial to understanding protein function. 15N CEST experiments are now routinely used to study slow conformational exchange of protein molecules between a 'visible' major state and 'invisible' minor states. These experiments have also been adapted to measure the solvent exchange rates of amide protons by exploiting the one bond deuterium isotope effect on the amide 15N chemical shifts. However at moderately high temperatures (~ 50 °C) that are sometimes required to populate protein minor conformers to levels (~ 1%) that can be detected by CEST experiments solvent H/D exchange can lead to 'dips' in low B115N CEST profiles that can be wrongly assigned to the conformational exchange process being characterized. This is demonstrated in the case of ~ 18 kDa T4 Lysozyme (T4L) at 50 °C and the ~ 11 kDa E. coli hibernation promoting factor (HPF) at 52 °C. This problem is trivially solved by eliminating the exchangeable deuterons in the solvent by using either an external D2O lock or by using a small amount (~ 1-3%) of a molecule like d6-DMSO that does not contain exchangeable deuterons to lock the spectrometer.
Collapse
Affiliation(s)
- Ved Prakash Tiwari
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Subhendu Pandit
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India.
| |
Collapse
|
21
|
Abstract
The phenomenon of chemical or conformational exchange in NMR spectroscopy has enabled detailed characterization of time-dependent aspects of biomolecular function, including folding, molecular recognition, allostery, and catalysis, on timescales from microsecond to second. Importantly, NMR methods based on a variety of spin relaxation parameters have been developed that provide quantitative information on interconversion kinetics, thermodynamic properties, and structural features of molecular states populated to a fraction of a percent at equilibrium and otherwise unobservable by other NMR approaches. The ongoing development of more sophisticated experimental techniques and the necessity to apply these methods to larger and more complex molecular systems engenders a corresponding need for theoretical advances describing such techniques and facilitating data analysis in applications. This review surveys current aspects of the theory of chemical exchange, as utilized in ZZ-exchange; Hahn and Carr-Purcell-Meiboom-Gill (CPMG) spin-echo; and R1ρ, chemical exchange saturation transfer (CEST), and dark state saturation transfer (DEST) spin-locking experiments. The review emphasizes theoretical results for kinetic topologies with more than two interconverting states, both to obtain compact analytical forms suitable for data analysis and to establish conditions for distinguishability between alternative kinetic schemes.
Collapse
Affiliation(s)
- Arthur G Palmer
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States.
| | - Hans Koss
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
| |
Collapse
|
22
|
Sheng Y, Cao K, Li J, Hou Z, Yuan S, Huang G, Liu H, Liu Y. Selective Targeting of the Zinc Finger Domain of HIV Nucleocapsid Protein NCp7 with Ruthenium Complexes. Chemistry 2018; 24:19146-19151. [PMID: 30276894 DOI: 10.1002/chem.201803917] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/19/2018] [Indexed: 12/17/2022]
Abstract
Nucleocapsid protein 7 (NCp7) is an attractive target for anti-HIV drug development. Here we found that ruthenium complexes are reactive to NCp7 and various Ru-agents exhibit significantly different reactivity. Interestingly, the zinc-finger domains of NCp7 also demonstrate different affinity to Ru-complexes; the C-terminal domain is much more reactive than the N-terminal domain. Each zinc-finger domain of NCp7 binds up to three Ru-motifs, and the ruthenium binding causes zinc-ejection from NCp7 and disrupts the protein folding. Therefore, ruthenium complexes interfere with the DNA binding of NCp7 and interrupt the protein function. The different reactivity of Ru-agents suggests a feasible strategy for improving the targeting of NCp7 by ligand design. This work provides an insight into the mechanism of ruthenium complex with NCp7, and suggests more potential application of ruthenium drugs.
Collapse
Affiliation(s)
- Yaping Sheng
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Kaiming Cao
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Ji Li
- Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210046, Jiang Su, P.R. China
| | - Zhuanghao Hou
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Siming Yuan
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Guangming Huang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hongke Liu
- Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210046, Jiang Su, P.R. China
| | - Yangzhong Liu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| |
Collapse
|
23
|
Nikolayevskiy H, Scerba MT, Deschamps JR, Appella DH. Reaction Kinetics Direct a Rational Synthesis of an HIV-1 Inactivator of Nucleocapsid Protein 7 and Provide Mechanistic Insight into Cellular Metabolism and Antiviral Activity. Chemistry 2018; 24:9485-9489. [PMID: 29653024 DOI: 10.1002/chem.201801253] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Indexed: 12/14/2022]
Abstract
Mercaptobenzamide thioester SAMT-247 is a non-toxic, mutation-resistant HIV-1 maturation inhibitor with a unique mechanism of antiviral activity. NMR spectroscopic analyses of model reactions that mimic the cellular environment answered fundamental questions about the antiviral mechanism and inspired a high-yielding (64 % overall), scalable (75 mmol), and cost-effective ($4 mmol-1 ) three-step synthesis that will enable additional preclinical evaluation.
Collapse
Affiliation(s)
- Herman Nikolayevskiy
- Synthetic Bioactive Molecules Section, Laboratory of, Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of, Health (NIH), 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Michael T Scerba
- Synthetic Bioactive Molecules Section, Laboratory of, Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of, Health (NIH), 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| | - Jeffrey R Deschamps
- Naval Research Laboratory, Code 6910, 4555 Overlook Ave. SW, Washington D.C., 20375, USA
| | - Daniel H Appella
- Synthetic Bioactive Molecules Section, Laboratory of, Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of, Health (NIH), 8 Center Drive, Room 404, Bethesda, MD, 20892, USA
| |
Collapse
|
24
|
Ren W, Ji D, Xu X. Metal cofactor modulated folding and target recognition of HIV-1 NCp7. PLoS One 2018; 13:e0196662. [PMID: 29715277 PMCID: PMC5929515 DOI: 10.1371/journal.pone.0196662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/17/2018] [Indexed: 01/01/2023] Open
Abstract
The HIV-1 nucleocapsid 7 (NCp7) plays crucial roles in multiple stages of HIV-1 life cycle, and its biological functions rely on the binding of zinc ions. Understanding the molecular mechanism of how the zinc ions modulate the conformational dynamics and functions of the NCp7 is essential for the drug development and HIV-1 treatment. In this work, using a structure-based coarse-grained model, we studied the effects of zinc cofactors on the folding and target RNA(SL3) recognition of the NCp7 by molecular dynamics simulations. After reproducing some key properties of the zinc binding and folding of the NCp7 observed in previous experiments, our simulations revealed several interesting features in the metal ion modulated folding and target recognition. Firstly, we showed that the zinc binding makes the folding transition states of the two zinc fingers less structured, which is in line with the Hammond effect observed typically in mutation, temperature or denaturant induced perturbations to protein structure and stability. Secondly, We showed that there exists mutual interplay between the zinc ion binding and NCp7-target recognition. Binding of zinc ions enhances the affinity between the NCp7 and the target RNA, whereas the formation of the NCp7-RNA complex reshapes the intrinsic energy landscape of the NCp7 and increases the stability and zinc affinity of the two zinc fingers. Thirdly, by characterizing the effects of salt concentrations on the target RNA recognition, we showed that the NCp7 achieves optimal balance between the affinity and binding kinetics near the physiologically relevant salt concentrations. In addition, the effects of zinc binding on the inter-domain conformational flexibility and folding cooperativity of the NCp7 were also discussed.
Collapse
Affiliation(s)
- Weitong Ren
- School of Physics, Nanjing University, Nanjing 210093, China
| | - Dongqing Ji
- School of Physics, Nanjing University, Nanjing 210093, China
| | - Xiulian Xu
- School of Physical Science and Technology, Yangzhou University, Yangzhou 225002, China
- * E-mail:
| |
Collapse
|