Isolation of a thiol-dependent acid kininogenase from rat spleen.

The enzyme which could produce kinin-like peptides from rat plasma at acidic condition and at coexistence of thiol compound was separated from acid extract of rat spleen. The isolation procedure of this enzyme was established. Substrate specificity was examined against fluologenic substrates and two types of collagen. The purified enzyme was proved to have kinin-forming activity and also collagenlytic activity.