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  1. Article: Minor changes in electrostatics robustly increase VP40 membrane binding, assembly, and budding of Ebola virus matrix protein derived virus-like particles.

    Motsa, Balindile B / Sharma, Tej / Chapagain, Prem P / Stahelin, Robert V

    bioRxiv : the preprint server for biology

    2024  

    Abstract: Ebola virus (EBOV) is a filamentous negative-sense RNA virus which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle ...

    Abstract Ebola virus (EBOV) is a filamentous negative-sense RNA virus which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle to illuminate new drug targets. EBOV encodes for the matrix protein, VP40, which regulates assembly and budding of new virions from the inner leaflet of the host cell plasma membrane (PM). In this work we determine the effects of VP40 mutations altering electrostatics on PM interactions and subsequent budding. VP40 mutations that modify surface electrostatics affect viral assembly and budding by altering VP40 membrane binding capabilities. Mutations that increase VP40 net positive charge by one (e.g., Gly to Arg or Asp to Ala) increase VP40 affinity for phosphatidylserine (PS) and PI(4,5)P
    Language English
    Publishing date 2024-01-31
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.01.30.578092
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Minor electrostatic changes robustly increase VP40 membrane binding, assembly, and budding of Ebola virus matrix protein derived virus-like particles.

    Motsa, Balindile B / Sharma, Tej / Cioffi, Michael D / Chapagain, Prem P / Stahelin, Robert V

    The Journal of biological chemistry

    2024  Volume 300, Issue 5, Page(s) 107213

    Abstract: Ebola virus (EBOV) is a filamentous negative-sense RNA virus, which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus ... ...

    Abstract Ebola virus (EBOV) is a filamentous negative-sense RNA virus, which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle to illuminate new drug targets. EBOV encodes for the matrix protein, VP40, which regulates assembly and budding of new virions from the inner leaflet of the host cell plasma membrane (PM). In this work, we determine the effects of VP40 mutations altering electrostatics on PM interactions and subsequent budding. VP40 mutations that modify surface electrostatics affect viral assembly and budding by altering VP40 membrane-binding capabilities. Mutations that increase VP40 net positive charge by one (e.g., Gly to Arg or Asp to Ala) increase VP40 affinity for phosphatidylserine and phosphatidylinositol 4,5-bisphosphate in the host cell PM. This increased affinity enhances PM association and budding efficiency leading to more effective formation of virus-like particles. In contrast, mutations that decrease net positive charge by one (e.g., Gly to Asp) lead to a decrease in assembly and budding because of decreased interactions with the anionic PM. Taken together, our results highlight the sensitivity of slight electrostatic changes on the VP40 surface for assembly and budding. Understanding the effects of single amino acid substitutions on viral budding and assembly will be useful for explaining changes in the infectivity and virulence of different EBOV strains, VP40 variants that occur in nature, and for long-term drug discovery endeavors aimed at EBOV assembly and budding.
    Language English
    Publishing date 2024-03-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1016/j.jbc.2024.107213
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Role of phosphatidic acid lipids on plasma membrane association of the Ebola virus matrix protein VP40.

    Cioffi, Michael D / Husby, Monica L / Gerstman, Bernard S / Stahelin, Robert V / Chapagain, Prem P

    Biochimica et biophysica acta. Molecular and cell biology of lipids

    2024  Volume 1869, Issue 3, Page(s) 159464

    Abstract: The Ebola virus matrix protein VP40 is responsible for the formation of the viral matrix by localizing at the inner leaflet of the human plasma membrane (PM). Various lipid types, including PI(4,5) ... ...

    Abstract The Ebola virus matrix protein VP40 is responsible for the formation of the viral matrix by localizing at the inner leaflet of the human plasma membrane (PM). Various lipid types, including PI(4,5)P
    MeSH term(s) Humans ; Ebolavirus/metabolism ; Hemorrhagic Fever, Ebola/metabolism ; Cell Membrane/metabolism ; Molecular Dynamics Simulation ; Lipids/analysis
    Chemical Substances Lipids
    Language English
    Publishing date 2024-02-14
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 60-7
    ISSN 1879-2618 ; 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2618 ; 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbalip.2024.159464
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: A 5'-Flanking C/G Pair at the Core Region Enhances the Recognition and Binding of Kaiso to Methylated DNA.

    Thapa, Bidhya / Adhikari, Narayan P / Tiwari, Purushottam B / Chapagain, Prem P

    Journal of chemical information and modeling

    2022  Volume 63, Issue 7, Page(s) 2095–2103

    Abstract: Methyl CpG binding proteins (MBPs) are transcription factors that recognize the methylated CpG sites in DNA and mediate the DNA methylation signal into various downstream cellular processes. The C2H2 zinc finger (ZF) protein, Kaiso, also an MBP, ... ...

    Abstract Methyl CpG binding proteins (MBPs) are transcription factors that recognize the methylated CpG sites in DNA and mediate the DNA methylation signal into various downstream cellular processes. The C2H2 zinc finger (ZF) protein, Kaiso, also an MBP, preferentially binds to two symmetrically methylated CpG sites in DNA sequences via C-terminal C2H2 ZF domains and mediates the transcription regulation process. Investigation of the molecular mechanism of the recognition of methylated DNA (meDNA) by Kaiso is important to understand how this protein reads and translates this methylation signal into downstream transcription outcomes. Despite previous studies in Kaiso-meDNA interactions, detailed structural investigations on the sequence-specific interaction of Kaiso with the meDNA sequence are still lacking. In this work, we used molecular modeling and molecular dynamics (MD) simulation-based computational approaches to investigate the recognition of various methylated DNA sequences by Kaiso. Our MD simulation results show that the Kaiso-meDNA interaction is sequence specific. The recognition of meDNA by Kaiso is enhanced in the MeECad sequence compared to the MeCG2 sequence. Compared to the 5'-flanking T/A pair in MeCG2, both MeCG2_mutCG and MeECad sequences show that a C/G base pair allows GLU535 of Kaiso to preferably recognize and bind the core mCpG site. The core mCGmCG site is crucial for the recognition process and formation of a stable complex. Our results reveal that the 5'-flanking nucleotides are also important for the enhanced binding and recognition of methylated sites.
    MeSH term(s) CpG Islands ; Zinc Fingers/genetics ; Transcription Factors/chemistry ; DNA/chemistry ; Gene Expression Regulation ; DNA Methylation ; Protein Binding
    Chemical Substances Transcription Factors ; DNA (9007-49-2)
    Language English
    Publishing date 2022-12-23
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 190019-5
    ISSN 1549-960X ; 0095-2338
    ISSN (online) 1549-960X
    ISSN 0095-2338
    DOI 10.1021/acs.jcim.2c01294
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Structural and Dynamical Differences in the Spike Protein RBD in the SARS-CoV-2 Variants B.1.1.7 and B.1.351.

    Bhattarai, Nisha / Baral, Prabin / Gerstman, Bernard S / Chapagain, Prem P

    The journal of physical chemistry. B

    2021  Volume 125, Issue 26, Page(s) 7101–7107

    Abstract: The novel coronavirus (SARS-CoV-2) pandemic that started in late 2019 is responsible for hundreds of millions of cases worldwide and millions of fatalities. Though vaccines are available, the virus is mutating to form new strains among which are the ... ...

    Abstract The novel coronavirus (SARS-CoV-2) pandemic that started in late 2019 is responsible for hundreds of millions of cases worldwide and millions of fatalities. Though vaccines are available, the virus is mutating to form new strains among which are the variants B.1.1.7 and B.1.351 that demonstrate increased transmissivity and infectivity. In this study, we performed molecular dynamics simulations to explore the role of the mutations in the interaction of the virus spike protein receptor binding domain (RBD) with the host receptor ACE2. We find that the hydrogen bond networks are rearranged in the variants and also that new hydrogen bonds are established between the RBD and ACE2 as a result of mutations. We investigated three variants: the wild-type (WT), B.1.1.7, and B.1.351. We find that the B.1.351 variant (also known as 501Y.V2) shows larger flexibility in the RBD loop segment involving residue K484, yet the RBD-ACE2 complex shows higher stability. Mutations that allow a more flexible interface that can result in a more stable complex may be a factor contributing to the increased infectivity of the mutated variants.
    MeSH term(s) COVID-19 ; Humans ; Protein Binding ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/genetics ; Spike Glycoprotein, Coronavirus/metabolism
    Chemical Substances Spike Glycoprotein, Coronavirus
    Language English
    Publishing date 2021-06-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1520-5207
    ISSN (online) 1520-5207
    DOI 10.1021/acs.jpcb.1c01626
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Conformational Dynamics of mCherry Variants: A Link between Side-Chain Motions and Fluorescence Brightness.

    Mukherjee, Srijit / Manna, Premashis / Douglas, Nancy / Chapagain, Prem P / Jimenez, Ralph

    The journal of physical chemistry. B

    2022  Volume 127, Issue 1, Page(s) 52–61

    Abstract: The 3-fold higher brightness of the recently developed mCherry-XL red fluorescent protein (FP) compared to its progenitor, mCherry, is due to a significant decrease in the nonradiative decay rate underlying its increased fluorescence quantum yield. To ... ...

    Abstract The 3-fold higher brightness of the recently developed mCherry-XL red fluorescent protein (FP) compared to its progenitor, mCherry, is due to a significant decrease in the nonradiative decay rate underlying its increased fluorescence quantum yield. To examine the structural and dynamic role of the four mutations that distinguish the two FPs and closely related variants, we employed microsecond time scale, all-atom molecular dynamics simulations. The simulations revealed that the I197R mutation leads to the formation of multiple hydrogen-bonded contacts and increased rigidity of the β-barrel. In particular, mCherryXL showed reduced nanosecond time scale breathing of the gap between the β7 and β10-strands, which was previously shown to be the most flexible region of mCherry. Together with experimental results, the simulations also reveal steric interactions of residue 161 and a network of hydrogen-bonding interactions of the chromophore with residues at positions 59, 143, and 163 that are critical in perturbing the chromophore electronic structure. Finally, we shed light on the conformational dynamics of the conserved residues R95 and S146, which are hydrogen-bonded to the chromophore, and provide physical insights into the observed photophysics. To the best of our knowledge, this is the first study that evaluates the conformational space for a set of closely related FPs generated by directed evolution.
    MeSH term(s) Fluorescence ; Molecular Dynamics Simulation ; Protein Conformation ; Mutation ; Hydrogen
    Chemical Substances Hydrogen (7YNJ3PO35Z)
    Language English
    Publishing date 2022-12-27
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S. ; Research Support, N.I.H., Extramural
    ISSN 1520-5207
    ISSN (online) 1520-5207
    DOI 10.1021/acs.jpcb.2c05584
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: AT-hook peptides bind the major and minor groove of AT-rich DNA duplexes.

    Garabedian, Alyssa / Jeanne Dit Fouque, Kevin / Chapagain, Prem P / Leng, Fenfei / Fernandez-Lima, Francisco

    Nucleic acids research

    2022  Volume 50, Issue 5, Page(s) 2431–2439

    Abstract: The mammalian high mobility group protein AT-hook 2 (HMGA2) houses three motifs that preferentially bind short stretches of AT-rich DNA regions. These DNA binding motifs, known as 'AT-hooks', are traditionally characterized as being unstructured. Upon ... ...

    Abstract The mammalian high mobility group protein AT-hook 2 (HMGA2) houses three motifs that preferentially bind short stretches of AT-rich DNA regions. These DNA binding motifs, known as 'AT-hooks', are traditionally characterized as being unstructured. Upon binding to AT-rich DNA, they form ordered assemblies. It is this disordered-to-ordered transition that has implicated HMGA2 as a protein actively involved in many biological processes, with abnormal HMGA expression linked to a variety of health problems including diabetes, obesity, and oncogenesis. In the current work, the solution binding dynamics of the three 'AT-hook' peptides (ATHPs) with AT-rich DNA hairpin substrates were studied using DNA UV melting studies, fluorescence spectroscopy, native ion mobility spectrometry-mass spectrometry (IMS-MS), solution isothermal titration calorimetry (ITC) and molecular modeling. Results showed that the ATHPs bind to the DNA to form a single, 1:1 and 2:1, 'key-locked' conformational ensemble. The molecular models showed that 1:1 and 2:1 complex formation is driven by the capacity of the ATHPs to bind to the minor and major grooves of the AT-rich DNA oligomers. Complementary solution ITC results confirmed that the 2:1 stoichiometry of ATHP: DNA is originated under native conditions in solution.
    MeSH term(s) AT-Hook Motifs ; Animals ; DNA/chemistry ; High Mobility Group Proteins/metabolism ; Mammals/genetics ; Nucleic Acid Denaturation ; Peptides/genetics
    Chemical Substances High Mobility Group Proteins ; Peptides ; DNA (9007-49-2)
    Language English
    Publishing date 2022-03-09
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkac115
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Elucidating Residue-Level Determinants Affecting Dimerization of Ebola Virus Matrix Protein Using High-Throughput Site Saturation Mutagenesis and Biophysical Approaches.

    Narkhede, Yogesh B / Bhardwaj, Atul / Motsa, Balindile B / Saxena, Roopashi / Sharma, Tej / Chapagain, Prem P / Stahelin, Robert V / Wiest, Olaf

    The journal of physical chemistry. B

    2023  Volume 127, Issue 29, Page(s) 6449–6461

    Abstract: The Ebola virus (EBOV) is a filamentous virus that acquires its lipid envelope from the plasma membrane of the host cell it infects. EBOV assembly and budding from the host cell plasma membrane are mediated by a peripheral protein, known as the matrix ... ...

    Abstract The Ebola virus (EBOV) is a filamentous virus that acquires its lipid envelope from the plasma membrane of the host cell it infects. EBOV assembly and budding from the host cell plasma membrane are mediated by a peripheral protein, known as the matrix protein VP40. VP40 is a 326 amino acid protein with two domains that are loosely linked. The VP40 N-terminal domain (NTD) contains a hydrophobic α-helix, which mediates VP40 dimerization. The VP40 C-terminal domain has a cationic patch, which mediates interactions with anionic lipids and a hydrophobic region that mediates VP40 dimer-dimer interactions. The VP40 dimer is necessary for trafficking to the plasma membrane inner leaflet and interactions with anionic lipids to mediate the VP40 assembly and oligomerization. Despite significant structural information available on the VP40 dimer structure, little is known on how the VP40 dimer is stabilized and how residues outside the NTD hydrophobic portion of the α-helical dimer interface contribute to dimer stability. To better understand how VP40 dimer stability is maintained, we performed computational studies using per-residue energy decomposition and site saturation mutagenesis. These studies revealed a number of novel keystone residues for VP40 dimer stability just adjacent to the α-helical dimer interface as well as distant residues in the VP40 CTD that can stabilize the VP40 dimer form. Experimental studies with representative VP40 mutants in vitro and in cells were performed to test computational predictions that reveal residues that alter VP40 dimer stability. Taken together, these studies provide important biophysical insights into VP40 dimerization and may be useful in strategies to weaken or alter the VP40 dimer structure as a means of inhibiting the EBOV assembly.
    MeSH term(s) Humans ; Hemorrhagic Fever, Ebola/metabolism ; Ebolavirus/genetics ; Ebolavirus/metabolism ; Dimerization ; Mutagenesis ; Lipids/chemistry ; Viral Matrix Proteins/chemistry
    Chemical Substances Lipids ; Viral Matrix Proteins
    Language English
    Publishing date 2023-07-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ISSN 1520-5207
    ISSN (online) 1520-5207
    DOI 10.1021/acs.jpcb.3c01759
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Structural and Dynamical Differences in the Spike Protein RBD in the SARS-CoV-2 Variants B.1.1.7 and B.1.351

    Bhattarai, Nisha / Baral, Prabin / Gerstman, Bernard S. / Chapagain, Prem P.

    Journal of physical chemistry. 2021 June 10, v. 125, no. 26

    2021  

    Abstract: The novel coronavirus (SARS-CoV-2) pandemic that started in late 2019 is responsible for hundreds of millions of cases worldwide and millions of fatalities. Though vaccines are available, the virus is mutating to form new strains among which are the ... ...

    Abstract The novel coronavirus (SARS-CoV-2) pandemic that started in late 2019 is responsible for hundreds of millions of cases worldwide and millions of fatalities. Though vaccines are available, the virus is mutating to form new strains among which are the variants B.1.1.7 and B.1.351 that demonstrate increased transmissivity and infectivity. In this study, we performed molecular dynamics simulations to explore the role of the mutations in the interaction of the virus spike protein receptor binding domain (RBD) with the host receptor ACE2. We find that the hydrogen bond networks are rearranged in the variants and also that new hydrogen bonds are established between the RBD and ACE2 as a result of mutations. We investigated three variants: the wild-type (WT), B.1.1.7, and B.1.351. We find that the B.1.351 variant (also known as 501Y.V2) shows larger flexibility in the RBD loop segment involving residue K484, yet the RBD–ACE2 complex shows higher stability. Mutations that allow a more flexible interface that can result in a more stable complex may be a factor contributing to the increased infectivity of the mutated variants.
    Keywords Severe acute respiratory syndrome coronavirus 2 ; hydrogen ; hydrogen bonding ; molecular dynamics ; pandemic ; pathogenicity ; viruses
    Language English
    Dates of publication 2021-0610
    Size p. 7101-7107.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1520-5207
    DOI 10.1021/acs.jpcb.1c01626
    Database NAL-Catalogue (AGRICOLA)

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  10. Article ; Online: PI(4,5)P

    Johnson, Kristen A / Budicini, Melissa R / Bhattarai, Nisha / Sharma, Tej / Urata, Sarah / Gerstman, Bernard S / Chapagain, Prem P / Li, Sheng / Stahelin, Robert V

    Journal of lipid research

    2024  Volume 65, Issue 3, Page(s) 100512

    Abstract: Ebola virus (EBOV) causes severe hemorrhagic fever in humans and is lethal in a large percentage of those infected. The EBOV matrix protein viral protein 40 kDa (VP40) is a peripheral binding protein that forms a shell beneath the lipid bilayer in ... ...

    Abstract Ebola virus (EBOV) causes severe hemorrhagic fever in humans and is lethal in a large percentage of those infected. The EBOV matrix protein viral protein 40 kDa (VP40) is a peripheral binding protein that forms a shell beneath the lipid bilayer in virions and virus-like particles (VLPs). VP40 is required for virus assembly and budding from the host cell plasma membrane. VP40 is a dimer that can rearrange into oligomers at the plasma membrane interface, but it is unclear how these structures form and how they are stabilized. We therefore investigated the ability of VP40 to form stable oligomers using in vitro and cellular assays. We characterized two lysine-rich regions in the VP40 C-terminal domain (CTD) that bind phosphatidylinositol-4,5-bisphosphate (PI(4,5)P
    MeSH term(s) Humans ; Ebolavirus/metabolism ; Hemorrhagic Fever, Ebola/metabolism ; Lysine/metabolism ; Binding Sites ; Lipids ; Protein Binding
    Chemical Substances Lysine (K3Z4F929H6) ; Lipids
    Language English
    Publishing date 2024-01-29
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 80154-9
    ISSN 1539-7262 ; 0022-2275
    ISSN (online) 1539-7262
    ISSN 0022-2275
    DOI 10.1016/j.jlr.2024.100512
    Database MEDical Literature Analysis and Retrieval System OnLINE

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