Crystalline ribonuclease
Crystalline ribonuclease
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DOI：
10.1085/jgp.24.1.15
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发表时间：
1940-01-01
期刊：
影响因子：
--
通讯作者：
KUNITZ, M.
中科院分区：
文献类型：
--
作者：
KUNITZ, M.
从新鲜牛肉胰腺中分离出一种能消化酵母核酸的结晶酶。这种酶被称为“核糖核酸酶”，是一种可溶性的白蛋白型蛋白质。它的分子质量大约是15000。等电点在pH 8.0附近。核糖核酸酶将酵母核酸分裂成足够小的片段，以便轻易地通过胶膜或玻璃纸膜扩散。与未消化的酵母核酸不同，消化的分裂产物不能用冰醋酸或稀盐酸沉淀。酵母核酸的消化伴随着游离酸基团的逐渐形成，而没有任何显著的游离磷酸的解放。即使在100cC下加热短时间，核糖核酸酶在很宽的pH范围内也是稳定的。其最大稳定性在pH 2.0 ~ 4.5范围内。热或碱使核糖核酸酶的蛋白质变性，或胃蛋白酶对蛋白质的消化，会使该物质的酶活性相应下降%。摘要作者：Auth。夏
A crystalline enzyme capable of digesting yeast nucleic acid was isolated from fresh beef pancreas. The enzyme called "ribonuclease" was a soluble protein of albumin type. Its molecular wt. was about 15,000. Its isoelectric point was in the region of pH 8.0. Ribonuclease split yeast nucleic acid into fragments small enough to diffuse readily through collodion or cellophane membranes. The split products of digestion, unlike the undigested yeast nucleic acid, were not precipitable with glacial acetic acid or dilute hydrochloric acid. The digestion of yeast nucleic acid was accompanied by a gradual formation of free acid groups without any significant liberation of free phosphoric acid. Ribonuclease was stable over a wide range of pH even when heated for a short time at 100cC. Its maximum stability was in the range of pH 2.0 to 4.5. Denaturation of the protein of ribonuclease by heat or alkali, or digestion of the protein by pepsin, caused a corresponding % loss in the enzymatic activity of the material. || ABSTRACT AUTHORS: Auth. summ