title: Aldehyde and ketone substrate analogues inhibit the collagenase of Clostridium histolyticum.
abstract: The collagenase from Clostridium histolyticum is a mixture of several collagenases, all of which are zinc metalloproteases. This enzyme catalyzes the cleavage of the X-Gly peptide bond in the repeating sequence of collagen: -Gly-Pro-X-Gly-Pro-X-. Thus the S3, S2, and S1 subsites on the enzyme appear to be occupied by the sequence -Gly-Pro-X- and the S1', S2', and S3' subsites also by -Gly-Pro-X-. Short peptides up to and including N alpha-acyltetrapeptides containing the repeat sequence do not detectably inhibit the enzyme (IC50 greater than 10 mM). However, peptide aldehydes of the form aminoacyl-X-glycinal, presumably occupying the S1, S2, ..., Sn subsites, are inhibitors. The most potent of these was Pro6-Gly-Pro-glycinal, with an IC50 of 340 +/- 70 microM. The single peptide aldehyde investigated, which could occupy the S1' and S2' subsites, 4-oxobutanoyl-L-proline, did not inhibit collagenase (IC50 greater than 20 mM). The peptide ketone 5-benzamido-4-oxo-6-phenylhexanoyl-Pro-Ala (XXV), which could occupy the S1-S3' subsites, inhibits collagenase with an IC50 of 120 +/- 50 microM, over 80-fold more potently than its parent peptide analogue benzoyl-Phe-Gly-Pro-Ala (XXIII). The alcohol analogue of XXV, 5-benzamido-4-hydroxy-6-phenylhexanoyl-Pro-Ala (XXVI), is over 60-fold less potent with an IC50 of 8 +/- 2mM. Extending the peptide ketone XXV to occupy the S2-S3' subsites gave 5-(N alpha-carbobenzoxy-L-prolinamido)-4-oxo-6-phenylhexanoyl-Pro -Ala (XXVII). Surprisingly, XXVII had an IC50 of only 5.2 +/- 2 mM.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000447:Aldehydes / Q000494:pharmacology*; D003013:Clostridium / Q000201:enzymology*; D007202:Indicators and Reagents; D007659:Ketones / Q000494:pharmacology*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D003012:Microbial Collagenase / Q000037:antagonists & inhibitors*; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D000447:Aldehydes; D007202:Indicators and Reagents; D007659:Ketones; D009842:Oligopeptides; D003012:Microbial Collagenase