The action of trypsin and chymotrypsin on the reserve proteins of some leguminous seeds

Abstract

The action of trypsin on the reserve proteins of the leguminous seeds belonging to Vicieae and Phaseoleae tribes was investicated. The hydrolysis of11S and 7S proteins of Vicieae proceeds relatively fast and some of the proteins are hydrolyzed practically completely. The hydrolysis of most of the investigated reserve proteins of the Phaseoleae tribe proceeds much slower, while that of 7S proteins of four Phaseolus species of American origin stops after the cleavage of only 10-20% of peptide bonds capable of reacting. Analogous results were obtained studying the action of chymotrypsin on a more restricted number of proteins. Both trypsin and chymotrypsin hydrolyze the same parts of Ph. vulgaris 7S protein, splitting off peptides which can be separated on a Sephadex G-50 column. The nonhydrolyzable high molecular weight core has a slightly smaller sedimentation coefficient and a higher elelctrophoretic mobility than the native protein and is able to dimerize at high ionic strength. Urea does not alter the hydrolyzability of the core butt the latter is partially hydrolyzed after the action of urea or guanidine hydrocholoride in the presence of mercaptoethanol.

Comparative effects of limited tryptic hydrolysis on physicochemical and structural features of seed 11S globulins

“…The lower speed of the extensive cooperative proteolysis of helianthinin in comparison with that of broad bean legumin correlates with the difference in the stability of their structure determined by calorimetry. In a previous semiquantitative comparative study on a number of leguminous seed storage proteins, it was shown that the trypsinolysis of glycinin is also considerably slower than that of the other legumins [19]. More extensive protein degradation during the non-cooperative stage of helianthinin hydrolysis in comparison with broad bean legumin is most likely due to different course of their limited proteolysis.…”

Effect of temperature and enzyme/substrate ratio on the hydrolysis of pea protein isolates by trypsin

“…VAINTRAUB et al (1976) reported a different efficiency of hydrolysis of 11S and 7S globulins of Pisum sativum. BHATTY (1988) found that trypsin hydrolysed the albumin fraction of pea protein much faster than that of the globulin fraction.…”

Comparative digestibility of legume storage proteins

“…One research group (Vaintraub et al, 1976(Vaintraub et al, ,1979 that native glycinin is more readily hydrolyzed by trypsin, chymotrypsin, or pepsin than is native phaseolin. However, results from studies that report the degradation of legume storage proteins by proteinases generally cannot be compared since digestion conditions differ.…”