title: Identification of efficiently cleaved substrates for HIV-1 protease using a phage display library and use in inhibitor development.
abstract: The recognition sequences for substrate cleavage by aspartic protease of HIV-1 are diverse and cleavage specificities are controlled by complex interactions between at least six amino acids around the cleavage site. We have identified 45 efficiently cleaved peptide substrates of HIV-1 protease (PR) using substrate phage display, an approach that can elucidate both context-dependent and context-independent preferences at individual subsites of a protease substrate. Many of the selected peptides were cleaved more efficiently and had lower K(m) values than physiologically relevant substrates of HIV-1 PR. Therefore, mutations occurring in the cleavage sites of the Gag and Gag-pol polyproteins of HIV-1 could significantly lower the K(m) values to better compete against drugs for protease binding while maintaining cleavage rates necessary for viral replication. The most efficiently cleaved peptide substrate derived from these phage, Ac-GSGIF*LETSL-NH(2), was cleaved 60 times more efficiently and had a K(m) approximately 260 times lower than a nine-amino-acid peptide based on the natural reverse transcriptase/integrase cleavage site when assayed at pH 5.6, 0.2 M NaCl. The peptide substrates selected served as frameworks for synthesis of tight binding reduced amide inhibitors of HIV-1 PR. The results show that the most efficiently cleaved substrates serve as the best templates for synthesis of the tightest binding inhibitors. Thus, defining changes in substrate preferences for drug-resistant proteases may aid in the development of more efficacious inhibitors.
authors.affiliation: Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Beck
authors.forename: L
authors.initials: L
authors.lastname: Hervio
authors.forename: P E
authors.initials: PE
authors.lastname: Dawson
authors.forename: J H
authors.initials: JH
authors.lastname: Elder
authors.forename: E L
authors.initials: EL
authors.lastname: Madison
mesh_terms: D000577:Amides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D004352:Drug Resistance, Microbial; D019427:HIV Integrase / Q000737:chemistry / Q000378:metabolism; D016333:HIV Protease / Q000378:metabolism*; D017320:HIV Protease Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019151:Peptide Library; D011485:Protein Binding; D019163:Reducing Agents / Q000378:metabolism; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D000577:Amides; D017320:HIV Protease Inhibitors; D010446:Peptide Fragments; D019151:Peptide Library; D019163:Reducing Agents; D019427:HIV Integrase; D054303:HIV Reverse Transcriptase; D016333:HIV Protease