The structure/activity relationship in glyceraldehyde-3-phosphate dehydrogenase of pig muscle

The macromolecular digestion product obtained on limited proteolysis of glyceraldehyde-3-phosphate dehydrogenase (GPDH, EC 1.2.1.12) was fractionated into seven polypeptides. Their position in the known sequence of GPDH was established. The sites of chymotrypsin action at Phe-34, Tyr-91, Val-116, Leu-154, Leu-221 and Leu-246 were identified on the basis of N-terminal sequence and molecular weight of the peptides isolated. Cleavage of particular peptide bonds was related to the enzymatic activity.