THE ISOLATION OF PEPSIN-MODIFIED CATALASE AND ITS CATALYTIC PROPERTIES
1958 年 45 巻 4 号 p. 227-236
詳細
1958 年 45 巻 4 号 p. 227-236
1. From the peptic digest of catalase at pH 1.5 the pepsin-modified catalase (PMC), possessing generalized potential catalytic abilities as hemoprotein, was isolated. The purification of PMC consisted of ammonium sulfate fractionation between 0.40 and 0.85 saturation, precipitation with ammonium sulfate plus trichloracetic acid, and dialysis at pH 5.0, successively.
2. The PMC preparation showed a sole band at the starting line in its paper electrophoretic pattern (veronal buffer, pH 8.6, μ=0.1). PMC demonstrated a peculiar Soret band (the max. at 390 mμ), which was evidently changed on adding KCN or Na2S2O4.
3. PMC exhibited fairly strong activities of the peroxidatic guaiacol oxidation, and the oxidatic Nadi reaction (indophenol oxidase activity). PMC could catalyze aerobic oxidation of L-ascorbic acid (QO2=average 297). These catalytic activities of PMC were strongly inhibited by 10-3M KCN, considerably by 10-3M NaN3, and NaF.
4. PMC still had the protein part of catalase of a high molecular weight, and the loss of protein part in disintegration of catalase to PMC was calculated as about 36 per cent per hematin group from the values of E275/ E390 and E275/405, and 32 per cent from N and Fe contents.
5. Continuous paper electrophoresis of PMC yielded more active PMC fraction, which demonstrated markedly stronger peroxidatic activity and higher hematin content.
The auther wishes to express his thanks for helpful advises of Prof. S. Miyamoto and Prof. K. Kaziro and for technical assistance of Miss H. Suzuki.
