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牛胰脂肪酶。I. 分离、均一性及特性鉴定。

Bovine pancreatic lipase.I.Isolation, homogeneity, and characterization.

作者信息

Shahani K M, Khan I M, Chandan R C

出版信息

J Dairy Sci. 1976 Mar;59(3):369-75. doi: 10.3168/jds.S0022-0302(76)84214-2.

Abstract

Bovine pancreatic lipase was isolated in pure form by lyophilization of fresh bovine pancreas, extraction of the enzyme with sucrose solution, fractional precipitation with ammonium sulfate and acetone, followed by chromatography on Sephadex G-100. The specific activity of the purest lipase fraction was 1750 micromoles fatty acid, liberated in 30 min per milligram of protein, indicating a purification of approximately 473-fold, with an overall yield of about 42%. Homogeneity of the enzyme was confirmed by rechromatography on Sephadex G-100 as well as with the gel electrophoretic and ultracentrifugal techniques. The purified enzyme gave a typical protein ultraviolet absorption spectrum with maximum absorption at 276 nm and minimum at 252 nm. The purified enzyme exhibited a single pH optimum of 8.8 and an isoelectric point near pH 5.5. Its optimum temperature was 37 C, and its optimum substrate concentration was 10%. These properties resembled those of milk lipase.

摘要

通过对新鲜牛胰腺进行冻干、用蔗糖溶液提取酶、用硫酸铵和丙酮分级沉淀,然后在葡聚糖凝胶G - 100上进行色谱分离,以纯形式分离出牛胰脂肪酶。最纯的脂肪酶组分的比活性为每毫克蛋白质在30分钟内释放1750微摩尔脂肪酸,表明纯化了约473倍,总产率约为42%。通过在葡聚糖凝胶G - 100上重新色谱分离以及凝胶电泳和超速离心技术证实了酶的同质性。纯化后的酶给出了典型的蛋白质紫外吸收光谱,在276 nm处有最大吸收,在252 nm处有最小吸收。纯化后的酶表现出单一的最适pH值为8.8,等电点接近pH 5.5。其最适温度为37℃,最适底物浓度为10%。这些性质与乳脂肪酶的性质相似。

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