The preparation and chemical composition of the multiple forms of beta-glucuronidase from the female rat preputial gland.
The preparation and chemical composition of the multiple forms of beta-glucuronidase from the female rat preputial gland.
复制标题
雌性大鼠包皮腺多种形式β-葡萄糖醛酸酶的制备及其化学成分。
DOI：
10.1016/s0021-9258(19)41369-0
复制
发表时间：
1975
期刊：
影响因子：
--
通讯作者：
O. Touster
中科院分区：
文献类型：
--
作者：
Preputial;Gland;Ronald K. Keller;O. Touster
从雌性大鼠包皮腺中分离出来的β-葡萄糖醛酸酶先前已被证明是一种四聚体糖蛋白。现在，我们通过羟基磷灰石柱色谱法将酶分离成几种分子形式。三种主要形式（A、B 和 C）具有非常相似或相同的氨基酸组成，并且对 B 和 C 形式的动力学和稳定性研究表明这两种形式之间没有差异。然而，C 型比 A 型和 B 型含有更多的碳水化合物，而 A 型和 B 型的碳水化合物组成非常相似。 A型和B型的糖是甘露糖(2.8%)、葡萄糖胺(1.9%)、岩藻糖(0.2%)、半乳糖(0.16%)和葡萄糖(0.17%)。 C 型的甘露糖含量稍高，但更独特的是，岩藻糖 (0.6%)、半乳糖 (1.1%) 和葡萄糖 (1.5%) 含量更丰富。通过纸色谱法和气液色谱法确定了葡萄糖的存在，并进行了一些特殊实验以排除这种己糖存在于持久性污染物中的可能性。对唾液酸的直接化学分析一致表明酶中不存在这种糖。碳水化合物-蛋白质键对碱稳定的事实表明该键涉及天冬酰胺酰-N-乙酰葡糖胺残基。多肽链中的NH2末端氨基酸是亮氨酸。
Beta-Glucuronidase isolated from the preputial gland of the female rat has previously been shown to be a tetrameric glycoprotein. We have now separated the enzyme into several molecular forms by chromatography on hydroxylapatite columns. The three major forms (A, B, and C) have a very similar or identical amino acid composition, and kinetic and stability studies on forms B and C disclosed no differences between these two forms. However, from C contained much more carbohydrate than forms A and B, which were very similar in carbohydrate composition. The sugars in forms A and B are mannose (2.8%), glucosamine (1.9%), fucose (0.2%), galactose (0.16%), and glucose (0.17%). Form C is a little higher in mannose content, but, more distinctively, is much richer in fucose (0.6%), galactose (1.1%), and glucose (1.5%). The presence of glucose was established by paper chromatography as well as by gas-liquid chromatography, and several special experiments were performed to rule out the possibility that this hexose was present in a persistent contaminant. Direct chemical analysis for sialic acid consistently showed the absence of this sugar in the enzyme. The fact that the carbohydrate-protein linkage is alkali-stable suggests that the linkage involves an asparaginyl-N-acetylglucosamine residue. The NH2-terminal amino acid in the polypeptide chain is leucine.