The viral envelope glycoprotein gpl20 is responsible for the initial events in HIV-1 infection. In its unliganded state, gpl20 is characterized by the presence of intrinsically disordered domains. In particular, the residues that define the co-receptor binding epitope are disordered and only become binding competent when CD4 binds gp 120. The rational design and optimization of inhibitors require a precise knowledge ofthe contribution of each residue at the gp120/CD4 interface to the binding affinity and to the allosteric structuring process. These issues are addressed in terms of the following specific aims: 1. Thermodynamic characterization of the structural stability and cooperative linkage between binding sites in trimeric (solution and membrane bound) and monomeric gp 120 by utilizing a combination of microcalorimetric and structure-based thermodynamic studies. How do intersubunit interactions within the trimer modulate the functional behavior of gp 120? 2. Thermodynamic characterization of conformational changes associated with receptor, co-receptor and inhibitor binding in trimeric (solution and membrane bound) gp 120. These studies will utilize differential scanning calorimetry, isothermal titration calorimetry and spectroscopic probes. 3. CD4 binding allosterically activates gp 120 by triggering a major conformational change. What are the binding hotspots within the CD4/gp120 binding footprint? Do they overlap with the residues that initiate the allosteric cascade? Themodynamic-based alanine scanning mutagenesis will be used to identify binding and allosteric hotspots. Can we inhibit gp120 binding without triggering the allosteric activation cascade? Are the binding and allosteric hotspots the same in the monomer and trimer? Does the membrane affect the interactions? This fundamental information will drive the computational and synthetic components of the POI. 4. Development of thermodynamic guidelines for the design of highly potent, energy efficient gp 120 inhibitors. The thermodynamic signature of all inhibitor candidates will be determined calorimetrically as it captures the essential properties of inhibitors and can be used for further inhibitor optimization. 5. Development of thermodynamic guidelines for gp120 inhibitors that are effective against different HIV-1 subtypes and exhibit low susceptibility to potential drug resistant mutants.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
2P01GM056550-17A1
Application #
8603513
Study Section
Special Emphasis Panel (ZRG1-AARR-E (43))
Project Start
Project End
Budget Start
2013-09-30
Budget End
2014-08-31
Support Year
17
Fiscal Year
2013
Total Cost
$305,624
Indirect Cost
$116,967
Name
Drexel University
Department
Type
DUNS #
002604817
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Ross, Patrick; Weihofen, Wilhelm; Siu, Fai et al. (2015) Isothermal chemical denaturation to determine binding affinity of small molecules to G-protein coupled receptors. Anal Biochem 473:41-5
Madani, Navid; Princiotto, Amy M; Schön, Arne et al. (2014) CD4-mimetic small molecules sensitize human immunodeficiency virus to vaccine-elicited antibodies. J Virol 88:6542-55
Herschhorn, Alon; Gu, Christopher; Espy, Nicole et al. (2014) A broad HIV-1 inhibitor blocks envelope glycoprotein transitions critical for entry. Nat Chem Biol 10:845-52
Kwon, Young Do; LaLonde, Judith M; Yang, Yongping et al. (2014) Crystal structures of HIV-1 gp120 envelope glycoprotein in complex with NBD analogues that target the CD4-binding site. PLoS One 9:e85940
Miura, Takuya; Hidaka, Koushi; Azai, Yukiko et al. (2014) Optimization of plasmepsin inhibitor by focusing on similar structural feature with chloroquine to avoid drug-resistant mechanism of Plasmodium falciparum. Bioorg Med Chem Lett 24:1698-701
Munro, James B; Mothes, Walther (2014) The HIV-1 Env trimer in HD. Structure 22:935-6
Emileh, Ali; Duffy, Caitlin; Holmes, Andrew P et al. (2014) Covalent conjugation of a peptide triazole to HIV-1 gp120 enables intramolecular binding site occupancy. Biochemistry 53:3403-14
Evans, Sean L; Schön, Arne; Gao, Qimeng et al. (2014) HIV-1 Vif N-terminal motif is required for recruitment of Cul5 to suppress APOBEC3. Retrovirology 11:4
Afanador, Gustavo A; Matthews, Krista A; Bartee, David et al. (2014) Redox-dependent lipoylation of mitochondrial proteins in Plasmodium falciparum. Mol Microbiol 94:156-71
Courter, Joel R; Madani, Navid; Sodroski, Joseph et al. (2014) Structure-based design, synthesis and validation of CD4-mimetic small molecule inhibitors of HIV-1 entry: conversion of a viral entry agonist to an antagonist. Acc Chem Res 47:1228-37

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