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Biomedical subjects

H Holzer

Publications and source records attributed to H Holzer.

At least 181 records · Page 10Linked to original sources
PubMed1975

Formation of a complex between yeast proteinases A and B.

Sephadex G-100 gel filtration of a purified mixture of tryptophan-synthase-inactivating enzymes I and II from Saccharomyces cerevisiae, which had previously been identified as yeast proteinases A and B, yields two coincident peaks of tryptophan-synthase-inactivating activity and proteinase A and B activities. The peaks correspond to molecular weights of approximately 100 000 and 50 000. It could be demonstrated, with purified proteinases A and B, that the high molecular weight peaks is due to the formation of a stoichiometric complex between proteinases A and B. The AB complex can easily be separated into its constituent enzymes by DEAE-Sephadex chromatography. When in the AB complex, proteinase B molecules still bind the specific proteinase B inhibitor from yeast.

Macromolecular Substances↗
PubMed1974

Isolation and characterization of the carboxypeptidase Y inhibitor from yeast.

Rapid acetone fractionation of crude yeast extract at low temperature separates carboxypeptidase Y inhibitor from the carboxypeptidase Y-inhibitor complex. On a protein basis the inhibitor has been purified 890-fold, resulting in homogeneity as determined by disc electrophoresis and filtration on Sephadex G-75. The molecular weight was calculated to be about 25,000. The inhibitor is heat-labile in crude extracts, whereas in the purified form it loses only 11% of its activity when it is heated at 100 degrees for 5 min. The inhibitor is inactivated by the yeast proteinases A (EC 3.4.23.8) and B (EC 3.4.22.9), respectively, but not by carboxypeptidase Y (EC 3.4.12.8). The inhibitor inhibits carboxypeptidase Y at a 1.5:1.0 protein-based weight ratio by 80%. At the same concentration ratios, proteinases A and B from yeast, as well as bovine pancreas carboxypeptidases A and B, are not inhibited.

Acetone↗