Hydrophobic Core Flexibility Modulates Enzyme Activity in HIV-1 Protease
- 30 January 2012
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 134 (9), 4163-4168
- https://doi.org/10.1021/ja2095766
Abstract
Human immunodeficiency virus Type-1 (HIV-1) protease is crucial for viral maturation and infectivity. Studies of protease dynamics suggest that the rearrangement of the hydrophobic core is essential for enzyme activity. Many mutations in the hydrophobic core are also associated with drug resistance and may modulate the core flexibility. To test the role of flexibility in protease activity, pairs of cysteines were introduced at the interfaces of flexible regions remote from the active site. Disulfide bond formation was confirmed by crystal structures and by alkylation of free cysteines and mass spectrometry. Oxidized and reduced crystal structures of these variants show the overall structure of the protease is retained. However, cross-linking the cysteines led to drastic loss in enzyme activity, which was regained upon reducing the disulfide cross-links. Molecular dynamics simulations showed that altered dynamics propagated throughout the enzyme from the engineered disulfide. Thus, altered flexibility within the hydrophobic core can modulate HIV-1 protease activity, supporting the hypothesis that drug resistant mutations distal from the active site can alter the balance between substrate turnover and inhibitor binding by modulating enzyme activity.Keywords
This publication has 30 references indexed in Scilit:
- Comparing the Accumulation of Active- and Nonactive-Site Mutations in the HIV-1 ProteaseBiochemistry, 2004
- HIV‐1 protease molecular dynamics of a wild‐type and of the V82F/I84V mutant: Possible contributions to drug resistance and a potential new target site for drugsProtein Science, 2004
- Proteins in action: the physics of structural fluctuations and conformational changesCurrent Opinion in Structural Biology, 2003
- A Major Role for a Set of Non-Active Site Mutations in the Development of HIV-1 Protease Drug ResistanceBiochemistry, 2003
- Flap opening and dimer-interface flexibility in the free and inhibitor-bound HIV protease, and their implications for functionStructure, 1999
- Domain Flexibility in Retroviral Proteases: Structural Implications for Drug Resistant Mutations,Biochemistry, 1998
- Active human immunodeficiency virus protease is required for viral infectivity.Proceedings of the National Academy of Sciences of the United States of America, 1988
- Model building of disulfide bonds in proteins with known three-dimensional structureProtein Engineering, Design and Selection, 1988
- HTLV-III gag Protein Is Processed in Yeast Cells by the Virus pol -ProteaseScience, 1986
- Disulphide bridges in globular proteinsJournal of Molecular Biology, 1981