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Chaturvedi P, Kelich P, Nitka TA, Vuković L. Computational Modeling of the Virucidal Inhibition Mechanism for Broad-Spectrum Antiviral Nanoparticles and HPV16 Capsid Segments. J Phys Chem B 2021; 125:13122-13131. [PMID: 34845905 DOI: 10.1021/acs.jpcb.1c07436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Solid core nanoparticles (NPs) coated with sulfonated ligands that mimic heparan sulfate proteoglycans (HSPGs) can exhibit virucidal activity against many viruses that utilize HSPG interactions with host cells for the initial stages of infection. How the interactions of these NPs with large capsid segments of HSPG-interacting viruses lead to their virucidal activity has been unclear. Here, we describe the interactions between sulfonated NPs and segments of the human papilloma virus type 16 (HPV16) capsids using atomistic molecular dynamics simulations. The simulations demonstrate that the NPs primarily bind at the interfaces of two HPV16 capsid proteins. After equilibration, the distances and angles between capsid proteins in the capsid segments are larger for the systems in which the NPs bind at the interfaces of capsid proteins. Over time, NP binding can lead to breaking of contacts between two neighboring proteins. The revealed mechanism of NPs targeting the interfaces between pairs of capsid proteins can be utilized for designing new generations of virucidal materials and contribute to the development of new broad-spectrum non-toxic virucidal materials.
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Affiliation(s)
- Parth Chaturvedi
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Payam Kelich
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Tara A Nitka
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Lela Vuković
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
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Gossert ST, Parajuli B, Chaiken I, Abrams CF. Roles of variable linker length in dual acting virucidal entry inhibitors on HIV-1 potency via on-the-fly free energy molecular simulations. Protein Sci 2020; 29:2304-2310. [PMID: 32926485 PMCID: PMC7586904 DOI: 10.1002/pro.3949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/21/2020] [Accepted: 09/08/2020] [Indexed: 01/03/2023]
Abstract
The Dual-Acting Virolytic Entry Inhibitors, or DAVEI's, are a class of recombinant chimera fusion proteins consisting of a lectin, a flexible polypeptide linker, and a fragment of the membrane-proximal external region (MPER) of HIV-1 gp41. DAVEIs trigger virolysis of HIV-1 virions through interactions with the trimeric envelope glycoprotein complex (Env), though the details of these interactions are not fully determined as yet. The purpose of this work was to use structural modeling to rationalize a dependence of DAVEI potency on the molecular length of the linker connecting the two components. We used temperature accelerated molecular dynamics and on-the-fly parameterization to compute free energy versus end-to-end distance for two different linker lengths, DAVEI L0 (His6 ) and DAVEI L2 ([Gly4 Ser]2 His6 ). Additionally, an envelope model was created based on a cryo-electron microscopy-derived structure of a cleaved, soluble Env construct, with high-mannose glycans added which served as putative docking locations for the lectin, along with MPER added that served as a putative docking location for the MPER region of DAVEI (MPERDAVEI ). Using MD simulation, distances between the lectin C-terminus and Env gp41 MPER were measured. We determined that none of the glycans were close enough to gp41 MPER to allow DAVEI L0 to function, while one, N448, will allow DAVEI L2 to function. These findings are consistent with the previously determined dependence of lytic function on DAVEI linker lengths. This supports the hypothesis that DAVEI's engage Env at both glycans and the Env MPER in causing membrane poration and lysis.
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Affiliation(s)
- Steven T. Gossert
- Department of Chemical and Biological EngineeringDrexel UniversityPhiladelphiaPennsylvaniaUSA
| | - Bibek Parajuli
- Department of Biochemistry and Molecular BiologyDrexel University College of MedicinePhiladelphiaPennsylvaniaUSA
| | - Irwin Chaiken
- Department of Chemical and Biological EngineeringDrexel UniversityPhiladelphiaPennsylvaniaUSA
| | - Cameron F. Abrams
- Department of Chemical and Biological EngineeringDrexel UniversityPhiladelphiaPennsylvaniaUSA
- Department of Biochemistry and Molecular BiologyDrexel University College of MedicinePhiladelphiaPennsylvaniaUSA
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Ang CG, Hossain MA, Rajpara M, Bach H, Acharya K, Dick A, Rashad AA, Kutzler M, Abrams CF, Chaiken I. Metastable HIV-1 Surface Protein Env Sensitizes Cell Membranes to Transformation and Poration by Dual-Acting Virucidal Entry Inhibitors. Biochemistry 2020; 59:818-828. [PMID: 31942789 PMCID: PMC7362902 DOI: 10.1021/acs.biochem.9b01008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dual-acting virucidal entry inhibitors (DAVEIs) have previously been shown to cause irreversible inactivation of HIV-1 Env-presenting pseudovirus by lytic membrane transformation. This study examined whether this transformation could be generalized to include membranes of Env-presenting cells. Flow cytometry was used to analyze HEK293T cells transiently transfected with increasing amounts of DNA encoding JRFL Env, loaded with calcein dye, and treated with serial dilutions of microvirin (Q831K/M83R)-DAVEI. Comparing calcein retention against intact Env expression (via Ab 35O22) on individual cells revealed effects proportional to Env expression. "Low-Env" cells experienced transient poration and calcein leakage, while "high-Env" cells were killed. The cell-killing effect was confirmed with an independent mitochondrial activity-based cell viability assay, showing dose-dependent cytotoxicity in response to DAVEI treatment. Transfection with increasing quantities of Env DNA showed further shifts toward "High-Env" expression and cytotoxicity, further reinforcing the Env dependence of the observed effect. Controls with unlinked DAVEI components showed no effect on calcein leakage or cell viability, confirming a requirement for covalently linked DAVEI compounds to achieve Env transformation. These data demonstrate that the metastability of Env is an intrinsic property of the transmembrane protein complex and can be perturbed to cause membrane disruption in both virus and cell contexts.
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Affiliation(s)
- Charles G Ang
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
- School of Biomedical Engineering, Science, and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Md Alamgir Hossain
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Marg Rajpara
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Harry Bach
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
- School of Biomedical Engineering, Science, and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Kriti Acharya
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Adel A Rashad
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Michele Kutzler
- Department of Microbiology and Immunology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Cameron F Abrams
- Department of Chemical and Biological Engineering, College of Engineering , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Irwin Chaiken
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
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