Electrophoretical analysis of bovine whey hydrolyzates produced by plant endopeptidases

PARDO M.F., BRUNO M.A., LAZZA C.M., TORRES M.J., ERRASTI M.E., CAFFINI,N.O.

Rosario

Congreso; XLII Reunión Anual de la SAIB; 2006

Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular

Enzymatic hydrolysis of proteins allows to eliminate unwanted fractions or to modify functional properties. Three cysteine plant endopeptidases with basic optima pH isolated by us were used to partially hydrolyze bovine whey proteins and their peptide patterns are reported. Plant proteases were isolated from fruits of Bromelia hieronymi Mez (Bromeliaceae) (I), fruits of Bromelia balansae (Bromeliaceae) (II) and latex of Carica quercifolia (Caricaceae) (III). Hydrolysis was carried out at different temperatures and pH 6.6. Hydrolysates were subjected to denaturing electrophoresis in tricine gels composed of a stacking gel (4 %T), a separating gel (10 %T) and a resolution gel (16,5 %T), which is especially suitable to resolve the mixture of peptides produced. The electrophoretic profiles were analyzed by densitography. Characteristic and differential proteolytic patterns on the main Whey components were obtained for each protease. After 60 minutes maximum degradation rate is observed for â- lactoglobulin (I, II, II), and a partial degradation for á-lactalbumin (I, II, III). New peptides appeared in all hydrolysates in a range of 5-15 kDa. The patterns can be correlated with the modification of functional properties in several industrial processes.