title: Chromophoric peptide substrates for the spectrophotometric assay of HIV-1 protease.
abstract: Purified HIV-1 protease hydrolyzes H-Ser-Gln-Asn-Leu-Phe(NO2)-Leu-Asp-Gly-NH2 (Peptide 1) and acetyl-Arg-Lys-Ile-Leu-Phe(NO2)-Leu-Asp-Gly-NH2 (Peptide 2) between the (p-nitro)phenylalanyl and leucyl residues. The cleavage of Peptides 1 and 2 resulted in a decrease in uv absorbance at 310 nm. The HIV-1 protease-catalyzed peptidolysis of Peptides 1 and 2 was characterized by a linear time course at substrate turnover of less than 20%. The solubilities of these substrates at pH 5.0 were sufficient to provide initial rate measurements over a concentration range of 0.05-0.5 mM. Steady-state kinetic data and inhibition constants using both spectrophotometric and high performance liquid chromatography (HPLC) analysis of the peptidolysis of these substrates resulted in comparable values.
authors.affiliation: Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406.
authors.forename: T A
authors.initials: TA
authors.lastname: Tomaszek
authors.forename: V W
authors.initials: VW
authors.lastname: Magaard
authors.forename: H G
authors.initials: HG
authors.lastname: Bryan
authors.forename: M L
authors.initials: ML
authors.lastname: Moore
authors.forename: T D
authors.initials: TD
authors.lastname: Meek
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D010450:Endopeptidases / Q000032:analysis*; D015684:Gene Products, pol / Q000032:analysis*; D016333:HIV Protease; D015497:HIV-1 / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides; D011994:Recombinant Proteins; D013053:Spectrophotometry / Q000379:methods
chemical_list: D015684:Gene Products, pol; D009842:Oligopeptides; D011994:Recombinant Proteins; D010450:Endopeptidases; D016333:HIV Protease