title: Thiol-based inhibitors of mammalian collagenase. Substituted amide and peptide derivatives of the leucine analogue, 2-[(R,S)-mercaptomethyl]-4-methylpentanoic acid.
abstract: To define the inhibitory requirements of mammalian collagenase, several N-substituted amide and peptide derivatives of the mercaptomethyl analogue of leucine, 2-[(R,S)mercaptomethyl]-4-methylpentanoic acid (H psi[SCH2]-DL-leucine), were synthesized and tested as inhibitors of pig synovial collagenase with soluble type I collagen as substrate. H psi[SCH2]-DL-leucine (IC50 = 320 microM) was about 10 times more potent than the beta-mercaptomethyl compound, N-acetylcysteine. The amide of H psi[SCH2]-DL-leucine was six times more potent than the parent thiol acid. Aliphatic N-substituted amides were less potent than the unsubstituted amide, whereas the N-benzyl amide was slightly more potent. Dipeptides, particularly those with an aromatic group at P2', were up to 20-fold more potent, while tripeptides with an aromatic L-amino acid at P2' and Ala-NH2 at P3' were up to 2200 times more potent than H psi[SCH2]-DL-leucine. The resolved diastereomers of H psi[SCH2]-DL-Leu-Phe-Ala-NH2 inhibited by 50% at 0.3 and 0.04 microM, respectively. The most potent inhibitor synthesized, an isomer of H psi[SCH2]-DL-Leu-L-3-(2'-naphthyl)alanyl-Ala-NH2, exhibited an IC50 of 0.014 microM, a value about 300 times less than similar thiol-based analogues of the P'-cleavage sequence of type I collagen, H psi[SCH2]-DL-Leu-Ala-Gly-Gln-. These structure-function studies establish within the present series of compounds that the most effective inhibitors of mammalian collagenase are not closely related to the P2'-P3' elements of the cleavage site of the natural substrate but rather have an aromatic group at the P2' position and Ala-NH2 at the P3' position.
authors.affiliation: Department of Biochemistry, University of Louisville, Kentucky 40292.
authors.forename: K
authors.initials: K
authors.lastname: Darlak
authors.forename: R B
authors.initials: RB
authors.lastname: Miller
authors.forename: M S
authors.initials: MS
authors.lastname: Stack
authors.forename: A F
authors.initials: AF
authors.lastname: Spatola
authors.forename: R D
authors.initials: RD
authors.lastname: Gray
mesh_terms: D000577:Amides / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D004151:Dipeptides / Q000138:chemical synthesis / Q000494:pharmacology; D007700:Kinetics; D007930:Leucine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology*; D003012:Microbial Collagenase / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D013552:Swine; D013583:Synovial Membrane / Q000201:enzymology
chemical_list: D000577:Amides; D004151:Dipeptides; D009842:Oligopeptides; C063490:2-(mercaptomethyl)-4-methylpentanoic acid; D003012:Microbial Collagenase; D007930:Leucine