Separation of two PZ-peptidases from bovine dental follicle

Two PZ-peptidases (EC 3.4.-) (A and B) cleaving a synthetic substrate for collagenase, 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg (PZ-peptide) have been separated from the particulate fraction of bovine dental follicle. PZ-peptidase A had a molecular weight of 220 000, an optimum pH at 8.0-8.5, and a Km value of 67 muM toward PZ-peptide at pH 7.1, whereas PZ-peptidase B had a molecular weight of 20 000, an optimum pH at 6.5-6.7, and a Km value of 400 muM toward PZ-peptide at pH 7.1. Two similar enzymes were also isolated from the soluble fraction. Since the pH-activity curve of the crude tissue preparations such as homogenate, microsomes and soluble supernatant had two peaks at 6.5-6.7 and 8.0-8.5, both PZ-peptidase A and B may exist in situ as two independent active enzymes.