Abstract
Isolation and purification procedures of yeast pro-proteinase C are described. In order to obtain a good yield of the proenzyme, it was necessary to repeat the inactivating treatment of coexisting yeast proteinase A and to perform purification procedures as rapidly as possible at low temperature. The purified protein was homogeneous with respect to chromatographic, electrophoretic and sedimentation criteria. The proenzyme possessed no inherent activity for acetyl-L-tyrosine ethylester but a slight activation seemed to occur during the activity assay. The molecular weight of the proenzyme was 79, 200 as determined by the sedimentation and diffusion methods. Its other physicochemical properties were compared with those of proteinase C. The proenzyme as well as proteinase C was shown to be a glycoprotein which contains 8_??_12% true sugars.
