scholarly journals Molecular Basis for Reduced Cleavage Activity and Drug Resistance in D30N HIV-1 protease

2021 ◽  
Author(s):  
Subhash Chandra Bihani ◽  
Madhusoodan V Hosur
Keyword(s):  
Drug Resistance ◽  
Molecular Basis ◽  
Viral Fitness ◽  
Hiv Protease ◽  
Cross Resistance ◽  
Coulombic Interaction ◽  
Cleavage Activity ◽  
Hiv 1 ◽  
Paediatric Formulation ◽  
Haart Therapy

Nelfinavir is one of the FDA approved HIV-1 protease inhibitors and is a part of HAART therapy for the treatment of HIV-AIDS. Nelfinavir was the first HIV-1 protease inhibitor to be approved as a Paediatric formulation. The application of HAART had resulted into significant improvement in the life of AIDS patients. However, emergence of drug resistance in HIV-1 protease limited the use of many of these drugs including nelfinavir. A unique mutation observed frequently in patients treated with nelfinavir is D30N as it is selected exclusively by nelfinavir. It imparts very high resistance to nelfinavir but unlike other primary mutations does not give cross resistance to the majority of other drugs. D30N mutation also significantly reduces cleavage activity of HIV-1 protease and affects the viral fitness. Here, we have determined structures of D30N HIV-1 protease in unliganded form and in complex with the drug nelfinavir. These structures provide rationale for rduced cleavage activity and molecular basis of resistance induced by D30N mutation. The loss of coulombic interaction part of a crucial hydrogen bond between the drug and the enzyme, is a likely explanation for reduced affinity and drug resistance towards nelfinavir. The decreased catalytic activity of D30N HIV protease, due to altered interaction with substrates and reduced stability of folding core may be the reasons for reduced replicative capacity of the HIV harboring D30N HIV-1 protease.

Impact of genotypic diversity on selection of subtype-specific drug resistance profiles during raltegravir-based therapy in individuals infected with B and BF recombinant HIV-1 strains

2020 ◽  
Vol 75 (6) ◽  
pp. 1567-1574
Author(s):  
Daniela Sánchez ◽  
Solange Arazi Caillaud ◽  
Ines Zapiola ◽  
Silvina Fernandez Giuliano ◽  
Rosa Bologna ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Current Knowledge ◽  
Phylogenetic Analyses ◽  
Genotypic Diversity ◽  
Resistance Testing ◽  
Cross Resistance ◽  
Resistance Mutations ◽  
Middle Income ◽  
Subtype B ◽  
Hiv 1

Abstract Background Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate. Materials and methods HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses. Results Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs. Conclusions Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.

scholarly journals Mechanism of Darunavir (DRV)’s High Genetic Barrier to HIV-1 Resistance: A Key V32I Substitution in Protease Rarely Occurs, but Once It Occurs, It Predisposes HIV-1 To Develop DRV Resistance

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Manabu Aoki ◽  
Debananda Das ◽  
Hironori Hayashi ◽  
Hiromi Aoki-Ogata ◽  
Yuki Takamatsu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Amino Acid ◽  
Critical Role ◽  
Viral Fitness ◽  
Single Amino Acid ◽  
Amino Acid Substitutions ◽  
Wild Type ◽  
Genetic Barrier ◽  
High Level ◽  
Hiv 1

ABSTRACTDarunavir (DRV) has bimodal activity against HIV-1 protease, enzymatic inhibition and protease dimerization inhibition, and has an extremely high genetic barrier against development of drug resistance. We previously generated a highly DRV-resistant HIV-1 variant (HIVDRVRP51). We also reported that four amino acid substitutions (V32I, L33F, I54M, and I84V) identified in the protease of HIVDRVRP51are largely responsible for its high-level resistance to DRV. Here, we attempted to elucidate the role of each of the four amino acid substitutions in the development of DRV resistance. We found that V32I is a key substitution, which rarely occurs, but once it occurs, it predisposes HIV-1 to develop high-level DRV resistance. When two infectious recombinant HIV-1 clones carrying I54M and I84V (rHIVI54Mand rHIVI84V, respectively) were selected in the presence of DRV, V32I emerged, and the virus rapidly developed high-level DRV resistance. rHIVV32Ialso developed high-level DRV resistance. However, wild-type HIVNL4-3(rHIVWT) failed to acquire V32I and did not develop DRV resistance. Compared to rHIVWT, rHIVV32Iwas highly susceptible to DRV and had significantly reduced fitness, explaining why V32I did not emerge upon selection of rHIVWTwith DRV. When the only substitution is at residue 32, structural analysis revealed much stronger van der Waals interactions between DRV and I-32 than between DRV and V-32. These results suggest that V32I is a critical amino acid substitution in multiple pathways toward HIV-1’s DRV resistance development and elucidate, at least in part, a mechanism of DRV’s high genetic barrier to development of drug resistance. The results also show that attention should be paid to the initiation or continuation of DRV-containing regimens in people with HIV-1 containing the V32I substitution.IMPORTANCEDarunavir (DRV) is the only protease inhibitor (PI) recommended as a first-line therapeutic and represents the most widely used PI for treating HIV-1-infected individuals. DRV possesses a high genetic barrier to development of HIV-1’s drug resistance. However, the mechanism(s) of the DRV’s high genetic barrier remains unclear. Here, we show that the preexistence of certain single amino acid substitutions such as V32I, I54M, A71V, and I84V in HIV-1 protease facilitates the development of high-level DRV resistance. Interestingly, allin vitro-selected highly DRV-resistant HIV-1 variants acquired V32I but never emerged in wild-type HIV (HIVWT), and V32I itself rendered HIV-1 more sensitive to DRV and reduced viral fitness compared to HIVWT, strongly suggesting that the emergence of V32I plays a critical role in the development of HIV-1’s resistance to DRV. Our results would be of benefit in the treatment of HIV-1-infected patients receiving DRV-containing regimens.

scholarly journals Impact of Primary Elvitegravir Resistance-Associated Mutations in HIV-1 Integrase on Drug Susceptibility and Viral Replication Fitness

2013 ◽  
Vol 57 (6) ◽  
pp. 2654-2663 ◽  
Author(s):  
Michael E. Abram ◽  
Rebecca M. Hluhanich ◽  
Derrick D. Goodman ◽  
Kristen N. Andreatta ◽  
Nicolas A. Margot ◽  
...  
Keyword(s):  
Viral Replication ◽  
Drug Susceptibility ◽  
Viral Fitness ◽  
Cross Resistance ◽  
Replication Capacity ◽  
Strand Transfer ◽  
Recombinant Viruses ◽  
Transfer Inhibitor ◽  
Replication Fitness ◽  
Hiv 1

ABSTRACTElvitegravir (EVG) is an effective HIV-1 integrase (IN) strand transfer inhibitor (INSTI) in advanced clinical development. Primary INSTI resistance-associated mutations (RAMs) at six IN positions have been identified in HIV-1-infected patients failing EVG-containing regimens in clinical studies: T66I/A/K, E92Q/G, T97A, S147G, Q148R/H/K, and N155H. In this study, the effect of these primary IN mutations, alone and in combination, on susceptibility to the INSTIs EVG, raltegravir (RAL), and dolutegravir (DTG); IN enzyme activities; and viral replication fitness was characterized. Recombinant viruses containing the six most common mutations exhibited a range of reduced EVG susceptibility: 92-fold for Q148R, 30-fold for N155H, 26-fold for E92Q, 10-fold for T66I, 4-fold for S147G, and 2-fold for T97A. Less commonly observed primary IN mutations also showed a range of reduced EVG susceptibilities: 40- to 94-fold for T66K and Q148K and 5- to 10-fold for T66A, E92G, and Q148H. Some primary IN mutations exhibited broad cross-resistance between EVG and RAL (T66K, E92Q, Q148R/H/K, and N155H), while others retained susceptibility to RAL (T66I/A, E92G, T97A, and S147G). Dual combinations of primary IN mutations further reduced INSTI susceptibility, replication capacity, and viral fitness relative to either mutation alone. Susceptibility to DTG was retained by single primary IN mutations but reduced by dual mutation combinations with Q148R. Primary EVG RAMs also diminished IN enzymatic activities, concordant with their structural proximity to the active site. Greater reductions in viral fitness of dual mutation combinations may explain why some primary INSTI RAMs do not readily coexist on the same HIV-1 genome but rather establish independent pathways of resistance to EVG.

scholarly journals Molecular Basis for Increased Susceptibility of Isolates with Atazanavir Resistance-Conferring Substitution I50L to Other Protease Inhibitors

2005 ◽  
Vol 49 (9) ◽  
pp. 3825-3832 ◽  
Author(s):  
Joseph Yanchunas ◽  
David R. Langley ◽  
Li Tao ◽  
Ronald E. Rose ◽  
Jacques Friborg ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Hiv Protease ◽  
Cross Resistance ◽  
Titration Calorimetry ◽  
Binding Affinities ◽  
The Novel ◽  
Immunodeficiency Virus ◽  
Effective Drugs ◽  
Hiv 1

ABSTRACT Protease inhibitors (PIs) are highly effective drugs against the human immunodeficiency virus (HIV), yet long-term therapeutic use is limited by emergence of HIV type 1 (HIV-1) protease substitutions that confer cross-resistance to multiple protease inhibitor drugs. Atazanavir is a highly potent HIV protease inhibitor with a distinct resistance profile that includes effectiveness against most HIV-1 isolates resistant to one or two PIs. The signature resistance substitution for atazanavir is I50L, and it is frequently (53%) accompanied by a compensatory A71V substitution that helps restore viability and increases atazanavir resistance levels. We measured the binding affinities of wild-type (WT) and I50L/A71V HIV-1 proteases to atazanavir and other currently approved PIs (ritonavir, lopinavir, saquinavir, nelfinavir, indinavir, and amprenavir) by isothermal titration calorimetry. Remarkably, we find that all of the PIs have 2- to 10-fold increased affinities for I50L/A71V protease, except for atazanavir. The results are also manifested by thermal stability measures of affinity for WT and I50L/A71V proteases. Additional biophysical and enzyme kinetics experiments show I50L/A71V protease is a stable enzyme with catalytic activity that is slightly reduced (34%) relative to the WT. Computational modeling reveals that the unique resistance phenotype of I50L/A71V protease likely originates from bulky tert-butyl groups at P2 and P2′ (specific to atazanavir) that sterically clash with methyl groups on residue L50. The results of this study provide a molecular understanding of the novel hypersusceptibility of atazanavir-resistant I50L/A71V-containing clinical isolates to other currently approved PIs.

scholarly journals Impaired Replication Capacity of Acute/Early Viruses in Persons Who Become HIV Controllers

2010 ◽  
Vol 84 (15) ◽  
pp. 7581-7591 ◽  
Author(s):  
Toshiyuki Miura ◽  
Zabrina L. Brumme ◽  
Mark A. Brockman ◽  
Pamela Rosato ◽  
Jennifer Sela ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Viral Replication ◽  
Acute Infection ◽  
Viral Fitness ◽  
Replication Capacity ◽  
Transmitted Drug Resistance ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Hiv Controllers ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) controllers maintain viremia at <2,000 RNA copies/ml without antiretroviral therapy. Viruses from controllers with chronic infection were shown to exhibit impaired replication capacities, in part associated with escape mutations from cytotoxic-T-lymphocyte (CTL) responses. In contrast, little is known about viruses during acute/early infection in individuals who subsequently become HIV controllers. Here, we examine the viral replication capacities, HLA types, and virus sequences from 18 HIV-1 controllers identified during primary infection. g ag-protease chimeric viruses constructed using the earliest postinfection samples displayed significantly lower replication capacities than isolates from persons who failed to control viremia (P = 0.0003). Protective HLA class I alleles were not enriched in these early HIV controllers, but viral sequencing revealed a significantly higher prevalence of drug resistance mutations associated with impaired viral fitness in controllers than in noncontrollers (6/15 [40.0%] versus 10/80 [12.5%], P = 0.018). Moreover, of two HLA-B57-positive (B57+) controllers identified, both harbored, at the earliest time point tested, signature escape mutations within Gag that likewise impair viral replication capacity. Only five controllers did not express “protective” alleles or harbor viruses with drug resistance mutations; intriguingly, two of them displayed typical B57 signature mutations (T242N), suggesting the acquisition of attenuated viruses from B57+ donors. These data indicate that acute/early stage viruses from persons who become controllers have evidence of reduced replication capacity during the initial stages of infection which is likely associated with transmitted or acquired CTL escape mutations or transmitted drug resistance mutations. These data suggest that viral dynamics during acute infection have a major impact on HIV disease outcome.

Molecular Basis of HIV-1 Protease Drug Resistance:  Structural Analysis of Mutant Proteases Complexed with Cyclic Urea Inhibitors†

Biochemistry ◽  
1997 ◽  
Vol 36 (7) ◽  
pp. 1573-1580 ◽  
Author(s):  
Paul J. Ala ◽  
Edward E. Huston ◽  
Ronald M. Klabe ◽  
Denise D. McCabe ◽  
Jodie L. Duke ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Structural Analysis ◽  
Molecular Basis ◽  
Hiv 1

Molecular basis of bortezomib resistance: proteasome subunit β5 (PSMB5) gene mutation and overexpression of PSMB5 protein

Blood ◽  
2008 ◽  
Vol 112 (6) ◽  
pp. 2489-2499 ◽  
Author(s):  
Ruud Oerlemans ◽  
Niels E. Franke ◽  
Yehuda G. Assaraf ◽  
Jacqueline Cloos ◽  
Ina van Zantwijk ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Drug Resistance ◽  
Molecular Basis ◽  
Proteasome Inhibitor ◽  
Acquired Resistance ◽  
Binding Pocket ◽  
Cross Resistance ◽  
Chemotherapeutic Drugs ◽  
Proteasome Subunits

AbstractThe proteasome inhibitor bortezomib is a novel anticancer drug that has shown promise in the treatment of refractory multiple myeloma. However, its clinical efficacy has been hampered by the emergence of drug-resistance phenomena, the molecular basis of which remains elusive. Toward this end, we here developed high levels (45- to 129-fold) of acquired resistance to bortezomib in human myelomonocytic THP1 cells by exposure to stepwise increasing (2.5-200 nM) concentrations of bortezomib. Study of the molecular mechanism of bortezomib resistance in these cells revealed (1) an Ala49Thr mutation residing in a highly conserved bortezomib-binding pocket in the proteasome β5-subunit (PSMB5) protein, (2) a dramatic overexpression (up to 60-fold) of PSMB5 protein but not of other proteasome subunits including PSMB6, PSMB7, and PSMA7, (3) high levels of cross-resistance to β5 subunit-targeted cytotoxic peptides 4A6, MG132, MG262, and ALLN, but not to a broad spectrum of chemotherapeutic drugs, (4) no marked changes in chymotrypsin-like proteasome activity, and (5) restoration of bortezomib sensitivity in bortezomib-resistant cells by siRNA-mediated silencing of PSMB5 gene expression. Collectively, these findings establish a novel mechanism of bortezomib resistance associated with the selective overexpression of a mutant PSMB5 protein.

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