title: 13C- and 1H-NMR studies of oxyanion and tetrahedral intermediate stabilization by the serine proteinases: optimizing inhibitor warhead specificity and potency by studying the inhibition of the serine proteinases by peptide-derived chloromethane and glyoxal inhibitors.
abstract: Catalysis by the serine proteinases proceeds via a tetrahedral intermediate whose oxyanion is stabilized by hydrogen-bonding in the oxyanion hole. There have been extensive (13)C-NMR studies of oxyanion and tetrahedral intermediate stabilization in trypsin, subtilisin and chymotrypsin using substrate-derived chloromethane inhibitors. One of the limitations of these inhibitors is that they irreversibly alkylate the active-site histidine residue which results in the oxyanion not being in the optimal position in the oxyanion hole. Substrate-derived glyoxal inhibitors are reversible inhibitors which, if they form tetrahedral adducts in the same way as substrates form tetrahedral intermediates, will overcome this limitation. Therefore we have synthesized (13)C-enriched substrate-derived glyoxal inhibitors which have allowed us to use (13)C-NMR and (1)H-NMR to determine how they interact with proteinases. It is hoped that these studies will help in the design of specific and highly potent warheads for serine proteinase inhibitors.
authors.affiliation: UCD School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, UCD Conway Institute, University College Dublin, Dublin 4, Ireland. J.Paul.G.Malthouse@ucd.ie
authors.forename: J P G
authors.initials: JP
authors.lastname: Malthouse
mesh_terms: D000595:Amino Acid Sequence; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D004795:Enzyme Stability; D006037:Glyoxal / Q000494:pharmacology; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008737:Methyl Chloride / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D011522:Protons; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D020860:Subtilisin / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D011522:Protons; D015842:Serine Proteinase Inhibitors; D006037:Glyoxal; D008737:Methyl Chloride; D012697:Serine Endopeptidases; D002918:Chymotrypsin; D020860:Subtilisin