Proteases occurring in the cell membrane: a possible cell receptor for the Bowman-Birk type of protease inhibitors.
The legume-derived Bowman-Birk trypsin and chymotrypsin protease inhibitors (BBI) are effective anticarcinogens in vivo and in vitro. The chymotrypsin-inhibitory domain has been shown to be responsible for this anticarcinogenic action. In this study we identify hydrolytic enzymes by their ability to hydrolyze the relatively specific chymotrypsin substrate succinyl-Ala-Ala-Pro-Phe-aminomethyl coumarin. Results presented in this study show: there is an approximately 2-fold increase in the activity of these enzyme(s) between normal and transformed C3H/10T1/2 cells; there are five such enzymes associated with transformed cells (separated by diethylaminoethyl-cellulose chromatography); only two of these enzymes are inhibited by BBI; the BBI-inhibitable enzymes are membrane associated; the BBI-inhibitable enzymes are similar to each other but different from pancreatic chymotrypsin. BBI has thus distinguished a subpopulation of enzymes capable of hydrolyzing succinyl-Ala-Ala-Pro-Phe-aminomethyl coumarin which may mediate the transformation of C3H/10T1/2 cells.
D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D010447:Peptide Hydrolases / Q000032:analysis*; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors; D010447:Peptide Hydrolases