3PWM

HIV-1 Protease Mutant L76V with Darunavir

Summary for 3PWM

• Entry DOI: 10.2210/pdb3pwm/pdb
• Related: 2IEN 3PWR
• Descriptor: Protease, CHLORIDE ION, ACETATE ION, ... (6 entities in total)
• Functional Keywords: hiv-1, protease, mutation l76v, darunavir, hydrolase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Human immunodeficiency virus 1
• Cellular location: Matrix protein p17: Virion (Potential). Capsid protein p24: Virion (Potential). Nucleocapsid protein p7: Virion (Potential). Reverse transcriptase/ribonuclease H: Virion (Potential). Integrase: Virion (Potential): P03367
• Total number of polymer chains: 2
• Total formula weight: 22271.99

Authors

Zhang, Y.,Weber, I.T. (deposition date: 2010-12-08, release date: 2011-04-20, Last modification date: 2023-09-13)

Primary citation

Louis, J.M.,Zhang, Y.,Sayer, J.M.,Wang, Y.F.,Harrison, R.W.,Weber, I.T.
The L76V Drug Resistance Mutation Decreases the Dimer Stability and Rate of Autoprocessing of HIV-1 Protease by Reducing Internal Hydrophobic Contacts.
Biochemistry, 50:4786-4795, 2011

PubMed Abstract: The mature HIV-1 protease (PR) bearing the L76V drug resistance mutation (PR(L76V)) is significantly less stable, with a >7-fold higher dimer dissociation constant (K(d)) of 71 ± 24 nM and twice the sensitivity to urea denaturation (UC(50) = 0.85 M) relative to those of PR. Differential scanning calorimetry showed decreases in T(m) of 12 °C for PR(L76V) in the absence of inhibitors and 5-7 °C in the presence of inhibitors darunavir (DRV), saquinavir (SQV), and lopinavir (LPV), relative to that of PR. Isothermal titration calorimetry gave a ligand dissociation constant of 0.8 nM for DRV, ∼160-fold higher than that of PR, consistent with DRV resistance. Crystal structures of PR(L76V) in complexes with DRV and SQV were determined at resolutions of 1.45-1.46 Å. Compared to the corresponding PR complexes, the mutated Val76 lacks hydrophobic interactions with Asp30, Lys45, Ile47, and Thr74 and exhibits closer interactions with Val32 and Val56. The bound DRV lacks one hydrogen bond with the main chain of Asp30 in PR(L76V) relative to PR, possibly accounting for the resistance to DRV. SQV shows slightly improved polar interactions with PR(L76V) compared to those with PR. Although the L76V mutation significantly slows the N-terminal autoprocessing of the precursor TFR-PR(L76V) to give rise to the mature PR(L76V), the coselected M46I mutation counteracts the effect by enhancing this rate but renders the TFR-PR(M46I/L76V) precursor less responsive to inhibition by 6 μM LPV while preserving inhibition by SQV and DRV. The correlation of lowered stability, higher K(d), and impaired autoprocessing with reduced internal hydrophobic contacts suggests a novel molecular mechanism for drug resistance.

PubMed: 21446746
DOI: 10.1021/bi200033z

Experimental method

X-RAY DIFFRACTION (1.46 Å)