title: Identification of novel mutations responsible for resistance to MK-2048, a second-generation HIV-1 integrase inhibitor.
abstract: MK-2048 represents a prototype second-generation integrase strand transfer inhibitor (INSTI) developed with the goal of retaining activity against viruses containing mutations associated with resistance to first-generation INSTIs, raltegravir (RAL) and elvitegravir (EVG). Here, we report the identification of mutations (G118R and E138K) which confer resistance to MK-2048 and not to RAL or EVG. These mutations were selected in vitro and confirmed by site-specific mutagenesis. G118R, which appeared first in cell culture, conferred low levels of resistance to MK-2048. G118R also reduced viral replication capacity to approximately 1% that of the isogenic wild-type (wt) virus. The subsequent selection of E138K partially restored replication capacity to approximately 13% of wt levels and increased resistance to MK-2048 to approximately 8-fold. Viruses containing G118R and E138K remained largely susceptible to both RAL and EVG, suggesting a unique interaction between this second-generation INSTI and the enzyme may be defined by these residues as a potential basis for the increased intrinsic affinity and longer "off" rate of MK-2048. In silico structural analysis suggests that the introduction of a positively charged arginine at position 118, near the catalytic amino acid 116, might decrease Mg(2+) binding, compromising enzyme function and thus leading to the significant reduction in both integration and viral replication capacity observed with these mutations.
authors.affiliation: McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada.
authors.forename: Tamara
authors.initials: T
authors.lastname: Bar-Magen
authors.forename: Richard D
authors.initials: RD
authors.lastname: Sloan
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Donahue
authors.forename: Björn D
authors.initials: BD
authors.lastname: Kuhl
authors.forename: Alexandra
authors.initials: A
authors.lastname: Zabeida
authors.forename: Hongtao
authors.initials: H
authors.lastname: Xu
authors.forename: Maureen
authors.initials: M
authors.lastname: Oliveira
authors.forename: Daria J
authors.initials: DJ
authors.lastname: Hazuda
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wainberg
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D004252:DNA Mutational Analysis; D024882:Drug Resistance, Viral; D019427:HIV Integrase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D019428:HIV Integrase Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D017434:Protein Structure, Tertiary; D011760:Pyrrolidinones / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology; D012367:RNA, Viral / Q000235:genetics; D000068898:Raltegravir Potassium; D014779:Virus Replication / Q000187:drug effects
chemical_list: D019428:HIV Integrase Inhibitors; D011760:Pyrrolidinones; D015363:Quinolones; D012367:RNA, Viral; D000068898:Raltegravir Potassium; C509700:elvitegravir; D019427:HIV Integrase; C514801:p31 integrase protein, Human immunodeficiency virus 1