ANALYSIS OF MANDELONITRILE LYASE AND BETA-GLUCOSIDASE FROM SWEET ALMONDS BY COMBINED ELECTROPHORETIC TECHNIQUES

Almonds are a rich source of mandelonitrile lyase (oxynitrilase) and b eta-glucosidase. The isolation of these two enzymes from sweet almonds requires fractional ammonium sulfate precipitation followed by ion-ex change chromatography on diethylaminoethyl-(DEAE) and carboxymethylcel lulose (CMC) columns. In the present investigation different electroph oretic techniques such as sodium dodecyl sulfate-polyacrylamide gel el ectrophoresis (SDS-PAGE), isoelectric focusing in immobilized pH gradi ents (IEF-IPG), and capillary electrophoresis were used to characteriz e these two enzymes. For the first time, beta-glucosidase and oxynitri lase were separated in an immobilized pH gradient of one pH unit. Capi llary zone electrophoresis (CZE) was an excellent tool for analysis of the purity of enzyme preparations, achieving complete separation of v arious protein constituents in only 15 min. CZE showed a resolving cap acity for the separation of enzyme forms comparable to that of isoelec tric focusing in an immobilized pH gradient.