title: Hirulog peptides with scissile bond replacements resistant to thrombin cleavage.
abstract: Using the natural protein hirudin as a model, a novel class of synthetic peptide inhibitors were recently designed. These inhibitors, 'hirulogs', retain the carboxy terminal Hir53-64 domain that interacts with the anion binding exosite of thrombin, connected via an oligoglycyl spacer unit to a catalytic site-directed moiety modeled on the sequence [D]Phe-Pro-Arg-X. The scissile Arg-X bond bond of substrate-like inhibitors has been modified to the proteolytic-resistant functions as beta-homo amino acids Arg psi [CH2CONH] X (2) and reduced bond analogues Arg psi [CH2N]X (3). Both classes of compounds demonstrate inhibition of thrombin amidolytic activity, and this active-site inhibition is highly sensitive to the P1' residue X. Thus these hirulog derivatives are resistant to thrombin proteolysis while maintaining substrate-like interactions with the active center. Finally, hirulog derivatives with non-cleavable replacements of the scissile bond are found to be effective anticoagulant agents.
authors.affiliation: BIOGEN, Inc., Cambridge, Massachusetts 02142.
authors.forename: T
authors.initials: T
authors.lastname: Kline
authors.forename: C
authors.initials: C
authors.lastname: Hammond
authors.forename: P
authors.initials: P
authors.lastname: Bourdon
authors.forename: J M
authors.initials: JM
authors.lastname: Maraganore
mesh_terms: D000595:Amino Acid Sequence; D006629:Hirudins / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D006801:Humans; D007202:Indicators and Reagents; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013917:Thrombin / Q000037:antagonists & inhibitors*
chemical_list: D006629:Hirudins; D007202:Indicators and Reagents; D009842:Oligopeptides; D013917:Thrombin