The human immunodeficiency virus type 1 (HIV-1) exploits a large number of host cellular proteins in its life cycle. Among the more prominent proteins is the human cyclophilin A (CypA) which is utilized by the virus for optimal infectivity and viral replication. A number of putative functions have been postulated for CypA but our understanding of its precise role within HIV-1 life cycle is still rudimentary. In response to the PA-06-388 announcement, a combined solution NMR and biophysical simulation investigation is proposed in the current R21/R33 application to determine the detailed three dimensional structure of the HIV-1 capsid protein (CA) bound to cyclophilin A. Because of its inherent flexibility, tendency to oligomerize, and its monomer-dimer equilibrium in solution, a structural study of the wild type full-length CA bound to CypA has frustrated attempts by crystallography and NMR spectroscopy. Thus in this investigation we will study the CypA/CA complex using a double mutant CA that exists as a monomer in solution, and retains all the critical properties of the wild type CA including assembly activity. Utilizing 3D/4D-NMR spectroscopy, residual dipolar coupling measurements and biophysical simulations, we will determine the detailed solution structure of the double mutant CA, and of its complex with human CypA. A knowledge of the detailed structure of the CypA/CA complex will provide a structural biology basis in enhancing our understanding of the precise role of CypA within the life cycle of the virus. Such a structure is also likely to contribute to the development of new inhibitors of CypA-CA interaction with therapeutic potential.

Public Health Relevance

This investigation is aimed at the determination of the detailed three dimensional structure of the human Cyclophilin A bound to a mutant capsid protein of HIV-1 virus using a combined solution NMR and biophysical simulation approach.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI081591-02
Application #
7779460
Study Section
AIDS Discovery and Development of Therapeutics Study Section (ADDT)
Program Officer
Salzwedel, Karl D
Project Start
2009-03-05
Project End
2012-02-28
Budget Start
2010-03-01
Budget End
2012-02-28
Support Year
2
Fiscal Year
2010
Total Cost
$194,347
Indirect Cost
Name
University of Alabama Birmingham
Department
Biochemistry
Type
Schools of Medicine
DUNS #
063690705
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Shin, Ronald; Tzou, Ywh-Min; Wong, Hing C et al. (2012) 1H, 15N, and 13C resonance assignments for a monomeric mutant of the HIV-1 capsid protein. Biomol NMR Assign 6:131-4
Shin, Ronald; Tzou, Ywh-Min; Krishna, N Rama (2011) Structure of a monomeric mutant of the HIV-1 capsid protein. Biochemistry 50:9457-67