1964 Volume 28 Issue 12 Pages 884-895
Proteolytic enzymes derived from thermophilic streptomyces sp. strain 1689 were purified and some properties were studied. A 8-fold purification was obtained from the culture supernatant by ammonium sulfate fractionation, acetone precipitation, and chromatography on CM-Sephadex. Two proteinases of almost identical properties were fractionated on CM-Sephadex chromatography. The purified preparations appeared to be homogeneous on ultracentrifugation. The optimum pH for proteolytic activity on casein was found to be pH 10.6_??_10.8. The stability was considerably increased by the addition of Ca++, and the proteinases exhibited a relatively high thermal stability. Enzyme activity was inhibited by oxidizing agents, PCMB, potato inhibitor, DFP, and heavy metal ions. Na+, K+, Mg++, and Fe++ showed an activating effect.
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