title: Inhibition of serine proteinases by squash inhibitors.
abstract: The squash inhibitors of serine proteinases have been discovered as proteins, which inhibit the catalytic activity of bovine trypsin. In this report we show, that three human enzymes of trypsin-like specificity - i.e. plasmin, plasma kallikrein and thrombin - are also inhibited by squash inhibitors. Moreover, rather strong inhibition was demonstrated for human cathepsin G. Lower association constants were found for Streptomyces griseus proteinase B (SGPB) and subtilisin BPN'. No association was detected for bovine chymotrypsin, even at millimolar concentrations of the inhibitors. Porcine pancreatic elastase showed extremely weak inhibition by squash inhibitors. Most of the enzymes examined did not exhibit a clear discrimination between P1 Arg and P1 Lys inhibitors. However, human plasma kallikrein and human thrombin formed much stronger complexes with CMTI I (P1-Arg) than with CPTI II (P1-Lys).
authors: Instytut Biochemii, Uniwersytet Wrocławski, Poland.
authors: J
authors: J
authors: Otlewski
authors: T
authors: T
authors: Zbyryt
authors: I
authors: I
authors: Krokoszyńska
authors: T
authors: T
authors: Wilusz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D005341:Fibrinolysin / Q000037:antagonists & inhibitors*; D006801:Humans; D007610:Kallikreins / Q000037:antagonists & inhibitors* / Q000097:blood; D007700:Kinetics; D008969:Molecular Sequence Data; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D013917:Thrombin / Q000037:antagonists & inhibitors*; D014675:Vegetables
chemical_list: D015842:Serine Proteinase Inhibitors; D007610:Kallikreins; D013917:Thrombin; D005341:Fibrinolysin