title: Adaptation of the plasma renin radioimmunoassay for use with HIV-1 protease.
abstract: We have demonstrated the use of a radioimmunoassay to quantitate the peptidolytic activity of human immunodeficiency virus, type 1 (HIV-1) protease using a tetradecapeptide substrate of porcine renin, Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-Leu-Val-Tyr-Ser. HIV-1 protease catalyzes cleavage of this substrate at the same Leu-Leu bond as does porcine renin, resulting in the formation of authentic angiotensin-I. The angiotensin-I product is then detected by use of a commercially available renin plasma assay kit, which constitutes the basis of the RIA. The radioimmunoassay provides detection of the protease-catalyzed formation of angiotensin-I at picomolar concentrations in vitro. We demonstrate the use of this assay in determining IC50 values for two HIV-1 protease inhibitors present in cell culture media and in standard assay buffer. An example of the potential development of this assay for the quantitation of these inhibitors present in ex vivo plasma samples is also presented.
authors.affiliation: Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406.
authors.forename: L J
authors.initials: LJ
authors.lastname: Hyland
authors.forename: T D
authors.initials: TD
authors.lastname: Meek
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016333:HIV Protease / Q000097:blood*; D017320:HIV Protease Inhibitors; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology; D011863:Radioimmunoassay / Q000379:methods*; D012083:Renin / Q000097:blood*; D013379:Substrate Specificity; D013552:Swine
chemical_list: D017320:HIV Protease Inhibitors; D010455:Peptides; D011480:Protease Inhibitors; D016333:HIV Protease; D012083:Renin