THE ANIONIC PROTEASE INHIBITOR BWI-1 FROM BUCKWHEAT SEEDS - KINETIC-PROPERTIES AND POSSIBLE BIOLOGICAL ROLE

Kinetic characteristics and effects on the growth of filamentous fungi of one of the main anionic protease inhibitors, BWI-1, isolated from buckwheat seeds, have been studied. The inhibition constants of bovine trypsin, chymotrypsin and cathepsin G from human granulocytes with BW I-1 were found to be 1.1, 67 and 200 nM, respectively. Analysis of the amino acid sequence of BWI-1 in the vicinity of the reactive site rev ealed its homology to the potato proteinase inhibitor I family. It is suggested that the inability of BWI-1 to bind elastase of human granul ocytes is due to the basic nature of the amino acid residue (Arg) at t he P-1 position in its reactive site. It was demonstrated that BWI-1 w as able to suppress the germination of the spores and the growth of th e mycelium of two filamentous fungi.