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Gupta M, Canziani G, Ang C, Mohammadi M, Abrams CF, Yang D, Smith AB, Chaiken I. Pharmacophore Variants of the Macrocyclic Peptide Triazole Inactivator of HIV-1 Env. RESEARCH SQUARE 2023:rs.3.rs-2814722. [PMID: 37131733 PMCID: PMC10153383 DOI: 10.21203/rs.3.rs-2814722/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Previously we established a family of macrocyclic peptide triazoles (cPTs) that inactivate the Env protein complex of HIV-1, and identified the pharmacophore that engages Env's receptor binding pocket. Here, we examined the hypothesis that the side chains of both components of the triazole Pro - Trp segment of cPT pharmacophore work in tandem to make intimate contacts with two proximal subsites of the overall CD4 binding site of gp120 to stabilize binding and function. Variations of the triazole Pro R group, which previously had been significantly optimized, led to identification of a variant MG-II-20 that contains a pyrazole substitution. MG-II-20 has improved functional properties over previously examined variants, with Kd for gp120 in the nM range. In contrast, new variants of the Trp indole side chain, with either methyl- or bromo- components appended, had disruptive effects on gp120 binding, reflecting the sensitivity of function to changes in this component of the encounter complex. Plausible in silico models of cPT:gp120 complex structures were obtained that are consistent with the overall hypothesisof occupancy by the triazole Pro and Trp side chains, respectively, into the β20/21 and Phe43 sub-cavities. The overall results strengthen the definition of the cPT-Env inactivator binding site and provide a new lead composition (MG-II-20) as well as structure-function findings to guide future HIV-1 Env inactivator design.
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Affiliation(s)
- Monisha Gupta
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
- Department of Chemistry, College of Arts and Sciences, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Gabriela Canziani
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Charles Ang
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Mohammadjavad Mohammadi
- Department of Chemical & Biological Engineering, College of Engineering, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Cameron F Abrams
- Department of Chemical & Biological Engineering, College of Engineering, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Derek Yang
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 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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Zhang S, Holmes AP, Dick A, Rashad AA, Enríquez Rodríguez L, Canziani GA, Root MJ, Chaiken IM. Altered Env conformational dynamics as a mechanism of resistance to peptide-triazole HIV-1 inactivators. Retrovirology 2021; 18:31. [PMID: 34627310 PMCID: PMC8501640 DOI: 10.1186/s12977-021-00575-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/20/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND We previously developed drug-like peptide triazoles (PTs) that target HIV-1 Envelope (Env) gp120, potently inhibit viral entry, and irreversibly inactivate virions. Here, we investigated potential mechanisms of viral escape from this promising class of HIV-1 entry inhibitors. RESULTS HIV-1 resistance to cyclic (AAR029b) and linear (KR13) PTs was obtained by dose escalation in viral passaging experiments. High-level resistance for both inhibitors developed slowly (relative to escape from gp41-targeted C-peptide inhibitor C37) by acquiring mutations in gp120 both within (Val255) and distant to (Ser143) the putative PT binding site. The similarity in the resistance profiles for AAR029b and KR13 suggests that the shared IXW pharmacophore provided the primary pressure for HIV-1 escape. In single-round infectivity studies employing recombinant virus, V255I/S143N double escape mutants reduced PT antiviral potency by 150- to 3900-fold. Curiously, the combined mutations had a much smaller impact on PT binding affinity for monomeric gp120 (four to ninefold). This binding disruption was entirely due to the V255I mutation, which generated few steric clashes with PT in molecular docking. However, this minor effect on PT affinity belied large, offsetting changes to association enthalpy and entropy. The escape mutations had negligible effect on CD4 binding and utilization during entry, but significantly altered both binding thermodynamics and inhibitory potency of the conformationally-specific, anti-CD4i antibody 17b. Moreover, the escape mutations substantially decreased gp120 shedding induced by either soluble CD4 or AAR029b. CONCLUSIONS Together, the data suggest that the escape mutations significantly modified the energetic landscape of Env's prefusogenic state, altering conformational dynamics to hinder PT-induced irreversible inactivation of Env. This work therein reveals a unique mode of virus escape for HIV-1, namely, resistance by altering the intrinsic conformational dynamics of the Env trimer.
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Affiliation(s)
- Shiyu Zhang
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Andrew P Holmes
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Adel A Rashad
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | | | - Gabriela A Canziani
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Michael J Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, OH, Columbus, USA.
| | - Irwin M Chaiken
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA.
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Rashad AA, Song LR, Holmes AP, Acharya K, Zhang S, Wang ZL, Gary E, Xie X, Pirrone V, Kutzler MA, Long YQ, Chaiken I. Bifunctional Chimera That Coordinately Targets Human Immunodeficiency Virus 1 Envelope gp120 and the Host-Cell CCR5 Coreceptor at the Virus-Cell Interface. J Med Chem 2018; 61:5020-5033. [PMID: 29767965 DOI: 10.1021/acs.jmedchem.8b00477] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To address the urgent need for new agents to reduce the global occurrence and spread of AIDS, we investigated the underlying hypothesis that antagonists of the HIV-1 envelope (Env) gp120 protein and the host-cell coreceptor (CoR) protein can be covalently joined into bifunctional synergistic combinations with improved antiviral capabilities. A synthetic protocol was established to covalently combine a CCR5 small-molecule antagonist and a gp120 peptide triazole antagonist to form the bifunctional chimera. Importantly, the chimeric inhibitor preserved the specific targeting properties of the two separate chimera components and, at the same time, exhibited low to subnanomolar potencies in inhibiting cell infection by different pseudoviruses, which were substantially greater than those of a noncovalent mixture of the individual components. The results demonstrate that targeting the virus-cell interface with a single molecule can result in improved potencies and also the introduction of new phenotypes to the chimeric inhibitor, such as the irreversible inactivation of HIV-1.
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Affiliation(s)
| | - Li-Rui Song
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China.,College of Pharmaceutical Sciences , Soochow University Medical College , Suzhou 215123 , China.,University of Chinese Academy of Sciences , Number 19A Yuquan Road , Beijing 100049 , China
| | | | | | - Shiyu Zhang
- School of Biomedical Engineering, Science and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Zhi-Long Wang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China
| | | | - Xin Xie
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China
| | | | | | - Ya-Qiu Long
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China.,College of Pharmaceutical Sciences , Soochow University Medical College , Suzhou 215123 , China
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Sepúlveda-Crespo D, de la Mata FJ, Gómez R, Muñoz-Fernández MA. Sulfonate-ended carbosilane dendrimers with a flexible scaffold cause inactivation of HIV-1 virions and gp120 shedding. NANOSCALE 2018; 10:8998-9011. [PMID: 29726564 DOI: 10.1039/c8nr01664j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Infection with human immunodeficiency virus type 1 (HIV-1) continues to be a global public health issue, especially in low-resource countries. Sexual transmission is responsible for the majority of HIV-1 infections worldwide. Women are more susceptible to HIV-1 acquisition than men and represent nearly 50% of the HIV-infected population. Topical vaginal microbicides that act at the earlier stages of infection offer a prevention strategy to reduce the acquisition of HIV-1. Dendrimers are nano-sized, radially symmetric molecules with a well-defined and monodisperse structure consisting of tree-like arms or branches. We perform a TZM.bl cell line-based screening of two families of carbosilane dendrimers (6 nanocompounds: G1-S12P, G2-S24P, G3-S48P, G1-C12P, G2-C24P and G3-C48P) that we have previously synthesized, containing 12, 24 or 48 sulfonate (or carboxylate) end-groups and a polyphenolic core. This work shows that second- and third-generation sulfonate-ended carbosilane dendrimers with a polyphenolic core (G2-S24P and G3-S48P, respectively) display low cytotoxicity (CC50 > 300 μM) with virucidal anti-R5-HIV-1 activity (EC50 < 50 nM; therapeutic index >6000) causing irreversible HIV-1 inactivation (80-90%) by loss of HIV-1 RNA (40%), gp120 shedding (70-80%) and p24 capsid protein release (45-60%). Herein, we demonstrate that sulfonate end-groups and a flexible scaffold from carbosilane dendrimers strongly influence their properties acting as potent virucides.
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Affiliation(s)
- Daniel Sepúlveda-Crespo
- Sección Inmunología, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Madrid 28007, Spain.
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Rashad AA, Acharya K, Haftl A, Aneja R, Dick A, Holmes AP, Chaiken I. Chemical optimization of macrocyclic HIV-1 inactivators for improving potency and increasing the structural diversity at the triazole ring. Org Biomol Chem 2017; 15:7770-7782. [PMID: 28770939 PMCID: PMC5614861 DOI: 10.1039/c7ob01448a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
HIV-1 entry inhibition remains an urgent need for AIDS drug discovery and development. We previously reported the discovery of cyclic peptide triazoles (cPTs) that retain the HIV-1 irreversible inactivation functions of the parent linear peptides (PTs) and have massively increased proteolytic resistance. Here, in an initial structure-activity relationship investigation, we evaluated the effects of variations in key structural and functional components of the cPT scaffold in order to produce a platform for developing next-generation cPTs. Some structural elements, including stereochemistry around the cyclization residues and Ile and Trp side chains in the gp120-binding pharmacophore, exhibited relatively low tolerance for change, reflecting the importance of these components for function. In contrast, in the pharmacophore-central triazole position, the ferrocene moiety could be successfully replaced with smaller aromatic rings, where a p-methyl-phenyl methylene moiety gave cPT 24 with an IC50 value of 180 nM. Based on the observed activity of the biphenyl moiety when installed on the triazole ring (cPT 23, IC50 ∼ 269 nM), we further developed a new on-resin synthetic method to easily access the bi-aryl system during cPT synthesis, in good yields. A thiophene-containing cPT AAR029N2 (36) showed enhanced entropically favored binding to Env gp120 and improved antiviral activity (IC50 ∼ 100 nM) compared to the ferrocene-containing analogue. This study thus provides a crucial expansion of chemical space in the pharmacophore to use as a starting point, along with other allowable structural changes, to guide future optimization and minimization for this important class of HIV-1 killing agents.
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Affiliation(s)
- Adel A. Rashad
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Kriti Acharya
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Ann Haftl
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | | | - Alexej Dick
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Andrew P. Holmes
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Irwin Chaiken
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
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