ANALYTIC AND IMMUNOLOGICAL CHARACTERIZATION OF CHICKPEA (CICER-ARIETINUM) PROTEIN HYDROLYSATES OBTAINED BY BROMELAIN AND ALPHA-CHYMOTRYPSIN

A water soluble concentrate of chickpea (Cicer arietinum) proteins was hydrolyzed by bromelain and alpha-chymotrypsn. Hydrolysis was verifie d by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulfate. The use of ELISA in an inhibition system, conducted with chic kpea protein antiserum raised in rabbits, showed that enzymatic hydrol ysis resulted in a considerable reduction in the antigenic character o f the proteins. Thus, the percentage inhibition by the alpha-chymotryp sin of hydrolysate was 58 +/- 2.3% and that by the bromelain hydrolysa te was 45 +/- 4.5%. The peptides were measured by size exclusion chrom atography. Peptides with molar mass lower than 1000 Da could be fracti onated into fraction F1 containing peptides with molar mass higher tha n 500 Da, fraction F2 containing peptides with molar mass included bet ween 200 and 500 Da, essentially small peptides containing 2, 3, or 4 amino acids, and fraction F3 containing free amino acids. The purified fractions were quantified with the TNBS method (2,4,6-trinitrobenzene sulfonic acid). The small peptides in fraction F2 were separated by re verse phase HPLC and were sequenced.