KINETIC PROPERTIES OF &β-GLUCOSIDASE FROM CASSAVA

Article abstract of DOI:10.1016/0031-9422(89)80101-3

Key Word Index--Manihot esculenta; cassava; β-glucosidase; linamarase; K_m values; inhibition kinetics.Abstract--β-Glucosidases from the leaf, peel and tuber cortex of cassava cv.Merah Jambu exhibited linamarase activity and had in common many kinetic properties.They were also capable of hydrolysing p-nitrophenyl-β-D-monoglycosides and cyanogenic β-monoglucosides but lacked activity towards the p-nitrophenyl-β-D-diglycosides, a cyanogenic diglucosides, and other β- or α-linked disaccharides.The K_m values for p-nitrophenyl-β-D-monoglycosides were generally lower than those for linamarin, prunasin and salicin.Ag(2+) inhibited both β-glucosidase and linamarase activities.Glucono-1,5-lactone inhibited the enzyme competitively, irrespective of the substrates used, while imidazole showed competitive inhibition with linamarin but non-competitive (mixed) inhibition with p-nitrophenyl-β-D-glucoside.The enzym was unaffected by glucose.