白鼠 大腦組織의 Alkaline Ribonuclease 의 部分精製 및 特性에 關한 硏究

PARTIAL PURIFICATION RIBONUCLEASE FROM AND CHARACTERIZATION OF AIKALINE GEREBRAL TISSUES OF ALBINO RATS

The alkaline RNase was partially purified from the cerebral tissues of albino rats and its characteristics influenced by numerous ions, changes of temperature, sulfhydryl reagent and several kinds of surfactants were observed. The following results were obtained. 1) The alkaline RNase was about 1200-fold purified by the consecutive processes of heating, salting- out and DEAE-Cellulose Column Chromatography. 2) The Km value of alkaline RNase, treated with the substrate of repurified yeast RNA, was 568/ig/ml. and followed the kinetics of Michaelis- Menten. 3) The optimal pH of alkaline RNase was 7.8 and the activities of alkaline RNase were maintained in a relatively broad range of pH. 4) The alkaline RNase was resistant to heat,especially more resistant in a homogenate and was stable in the presence of the substrates or other proteins. 5) The alkaline RNase was not significantly influenced by low concentration of pHMB (parahydroxy mercuribenzoate). 6) The activities of alkaline RNase were inhibited by divalent cations and slightly accelerated by Na+ and K+ in the range of 0. IM. and inhibited markedly by Li+. 7 ) Sodium dodecyl sulfate inhibited the activities of alkaline RNase markedly, but Tween-80 and Cetyltrimethylammouium chloride not change its activities.