Purification and characterization of benzoyl-L-tyrosine ethyl ester hydrolase from the yolk sac membrane of chicken egg.
Purification and characterization of benzoyl-L-tyrosine ethyl ester hydrolase from the yolk sac membrane of chicken egg.
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鸡蛋卵黄囊膜苯甲酰-L-酪氨酸乙酯水解酶的纯化和表征。
DOI：
10.1139/o86-076
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
M. Yamada
中科院分区：
文献类型：
--
作者：
Y. Sugimoto;M. Yamada
从18日龄鸡胚卵黄囊膜中分离纯化了一种水解苯甲酰-L-酪氨酸乙酯（BTEE）的酶。纯化的BTEE水解酶具有110，000的分子量，由70，000和40，000个亚基组成，并且胰凝乳蛋白酶的合成底物优选于胰蛋白酶的合成底物。该酶的最适pH为6.5-7.0，最适温度为40 ℃。在pH 6.5和30 ℃下，该酶的BTEE的Km值为16 mM。胰蛋白酶抑制剂对该酶几乎没有抑制作用，而胰凝乳蛋白酶抑制剂对该酶有明显的抑制作用。镁离子对酶的活性有激活作用，其激活作用与酶的纯度和浓度有关，而对氯汞苯甲酸盐和锌离子则使酶的活性明显失活。发现BTEE水解酶水解蛋白质如酪蛋白和血红蛋白。这些数据表明，该酶是一种类似胰凝乳蛋白酶的蛋白酶。该蛋白酶可作用于卵黄蛋白，提示其在卵黄囊膜层的卵黄代谢中起重要作用。
An enzyme which hydrolyzes benzoyl-L-tyrosine ethyl ester (BTEE) was purified from yolk sac membranes of day-18 chick embryos. The purified BTEE hydrolase has a molecular weight of 110,000, being composed of 70,000 and 40,000 subunits, and preferred synthetic substrates for chymotrypsin to those for trypsin. The optimum pH and temperature of this enzyme were 6.5-7.0 and 40 degrees C, respectively. The Km value for BTEE of the enzyme was 16 mM at pH 6.5 and 30 degrees C. The enzyme was inhibited markedly by some chymotrypsin inhibitors but scarcely inhibited by trypsin inhibitors. Magnesium ion acted as potent activator, depending on the enzyme purity and its concentration, whereas p-chloromercuribenzoate and zinc ion inactivated the activity markedly. The BTEE hydrolase was found to hydrolyze proteins such as casein and hemoglobin. These data indicated that the enzyme is a proteinase similar to chymotrypsin. This proteinase could act on yolk proteins, suggesting that it plays an important role in the metabolism of yolk at the yolk sac membrane layer.