Inclusion of full length human immunodeficiency virus type 1 (HIV-1) gag sequences in viral recombinants applied to drug susceptibility phenotyping.
PMID: 12088824
2002
Journal of virological methods
Abstract: Mutations known to cause retarded viral growth kinetics (RT M184V and PR I50V) were introduced and analyzed in parallel using both the new Five Prime HIV assay (FPH) and a standard recombinant virus assay (RVA).
Abstract: The M184V and I50V mutants produced up to 4.8- and 5.9-fold higher p24 antigen levels, respectively, with the FPH when compared to the cultures containing RVA-derived viruses.
A Comparative Insight into Amprenavir Resistance of Mutations V32I, G48V, I50V, I54V, and I84V in HIV-1 Protease Based on Thermodynamic Integration and MM-PBSA Methods.
Abstract: In both single- and multiple-cycle assay systems and in the context of I50V, the L449F and P453L changes consistently increased the 50% inhibitory concentration of APV, while the CS changes alone had no measurable effect on inhibitor sensitivity.
Abstract: In population-based sequence analyses the I50V mutant was invariably linked to either L449F or P453L.
Abstract: Purified I50V protease catalyzed cleavage of decapeptides incorporating the L449F or P453L change 10-fold and 22-fold more efficiently than cleavage of the wild-type substrate, respectively.
Abstract: Sequential plasma samples from one patient reveale
Overcoming drug resistance in HIV-1 chemotherapy: the binding thermodynamics of Amprenavir and TMC-126 to wild-type and drug-resistant mutants of the HIV-1 protease.
Abstract: Biochemical and clinical studies have shown that, unlike other inhibitors, Amprenavir is severely affected by the protease mutation I50V, located in the flap region of the enzyme.
Abstract: In this paper, we have studied the thermodynamic and molecular origin of the response of these two inhibitors to the I50V mutation and the double active-site mutation V82F/I84V that affects all existing clinical inhibitors.
Abstract: The mutations I50V and V82F/I84V lower the bin
Abstract: The mutations I50V and V82F/I84V lower the binding affinity of Amprenavir by a factor of 147 and 104, respectively.
Human immunodeficiency virus type 1 genotypic and pharmacokinetic determinants of the virological response to lopinavir-ritonavir-containing therapy in protease inhibitor-experienced patients.
PMID: 12183249
2002
Antimicrobial agents and chemotherapy
Abstract: Additional PI resistance mutations, including primary mutation I50V, could be selected in patients failing on LPV/r.
[Pharmacological study and clinical effect of HIV protease inhibitor amprenavir].
Abstract: One of the major concerns associated with anti-HIV agents is the resistance mutation development, and the presence of I50V, M46I/L, I47V, I54L/V and I84V genotype has been observed in amprenavir therapy experienced subjects.
A phase II trial of dual protease inhibitor therapy: amprenavir in combination with indinavir, nelfinavir, or saquinavir.
PMID: 11391165
2001
Journal of acquired immune deficiency syndromes (1999)
Abstract: The protease I50V mutation characteristic of APV resistance was not observed, although other key PI mutations were selected in 4 patients failing therapy, 2 of whom had PI resistance at baseline.
Structural and kinetic analyses of the protease from an amprenavir-resistant human immunodeficiency virus type 1 mutant rendered resistant to saquinavir and resensitized to amprenavir.
Abstract: Passage of the triple-mutant APV-resistant HIV-1 strain in MT4 cells, in the presence of increasing concentrations of saquinavir (SQV), gave rise to a new variant containing M46I, G48V, I50V, and I84L mutations in the protease and a resulting phenotype that was resistant to SQV and, unexpectedly, resensitized to APV.
Abstract: The protease inhibitor amprenavir (APV) generates a signature set of HIV type 1 (HIV-1) protease mutations associated with in vitro resistance (M46I/L, I47V, and I50V [triple mutant]).
Abstract: The switch in protease inhibitor sensitivities resulted from (i) the
In vitro selection and characterization of VX-478 resistant HIV-1 variants.
PMID: 9561202
1998
Advances in experimental medicine and biology
Abstract: By direct PCR analysis of selected viruses, a number of mutations were identified (L10F, M46I, I47V, I50V and I84V) in the protease gene.
Abstract: For VX-478, significant increases in IC90 and Ki were observed for virus or protease, respectively, containing I50V single mutation or an M46I/I47V/I50V triple mutation.
Kinetic characterization of human immunodeficiency virus type-1 protease-resistant variants.
PMID: 8663409
1996
The Journal of biological chemistry
Abstract: For the I50V mutant, the efficiency (kcat/Km) of processing peptides designed to mimic cleavage junctions in the HIV-1 gag-pol polypeptide was decreased up to 25-fold.
Abstract: The triple mutant had a 2-fold higher processing efficiency than the I50V single mutant for peptide substrates with Phe/Pro and Tyr/Pro cleavage sites, suggesting that the M46I and I47V mutations are compensatory.
Abstract: These analyses support the virological observation that the addition of M46I and I47V mutations on the I50V mutant background enables increased survival of the HIV-1 virus as it replicates in the presence of VX-478.
Abstract: We have characterized recombinant HIV-1
In vitro selection and characterization of human immunodeficiency virus type 1 (HIV-1) isolates with reduced sensitivity to hydroxyethylamino sulfonamide inhibitors of HIV-1 aspartyl protease.
Abstract: The mutant protease Ile-50-->Val displays a much lower affinity for the inhibitors than the parent enzyme (< or = 80-fold).
Abstract: This is the first observation in HIV protease resistance studies of an Ile-50-->Val mutation, a mutation that appears to arise uniquely against the sulfonamide inhibitor class.
Abstract: When the substitutions observed were introduced as single mutations into an HIV-1 infectious clone (HXB2), only the Ile-50-->Val mutant showed reduced sensitivity (two- to threefold) to VB-11,328 and VX-478.