Contribution of beta-glucuronidase to the degradation of chondroitin 4-sulfate by canine liver lysosomal enzymes.
Contribution of beta-glucuronidase to the degradation of chondroitin 4-sulfate by canine liver lysosomal enzymes.
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β-葡萄糖醛酸酶对犬肝溶酶体酶降解 4-硫酸软骨素的贡献。
DOI：
10.1620/tjem.127.317
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
K. Tsurumi
中科院分区：
文献类型：
--
作者：
S. Hayashi;A. Kimura;K. Tsurumi
在酸性条件下，犬肝溶酶体对源自硫酸软骨素4 - 硫酸盐（Ch4 - S）和软骨素的寡糖进行消化。根据消化产物的类型，研究了透明质酸酶和β - 葡萄糖醛酸酶对Ch4 - S的消化程度。源自Ch4 - S和软骨素的十四糖和十二糖首先被透明质酸酶消化，而八糖则被β - 葡萄糖醛酸酶水解。十糖被透明质酸酶和β - 葡萄糖醛酸酶两者降解。结果表明，与透明质酸（HA）的消化研究结果相反，在溶酶体酶对Ch4 - S的降解中，来自Ch4 - S的十糖是β - 葡萄糖醛酸酶的最大分子量底物。在反应混合物中存在β - 葡萄糖醛酸酶的特异性抑制剂糖 - 1,4 - 内酯的情况下，研究了β - 葡萄糖醛酸酶对透明质酸酶降解软骨素和HA的作用。添加糖 - 1,4 - 内酯显著降低了透明质酸酶对软骨素的解聚作用。从这些结果来看，提示β - 葡萄糖醛酸酶有助于降解抑制透明质酸酶对Ch4 - S解聚作用的偶数寡糖。
Oligosaccharides derived from chondroitin 4-sulfate (Ch4-S) and chondroitin were digested by canine liver lysosomes under acidic conditions. The degree of digestion of Ch4-S by hyaluronidase and beta-glucuronidase was examined on the basis of types of the digestion products. Tetradeca- and dodecasaccharides derived from Ch4-S and chondroitin were first digested by hyaluronidase, while the octasaccharide was hydrolyzed by beta-glucuronidase. Decasaccharide was degraded by both hyaluronidase and beta-glucuronidase. The results showed that decasaccharide from Ch4-S served as the largest-molecular-weight substrate for beta-glucuronidase in the degradation of Ch4-S by the enzymes of lysosomes in contrast to the results of the digestion studies of hyaluronic acid (HA). The contribution of beta-glucuronidase to the depolymerization of chondroitin and HA by hyaluronidase was examined in the presence of saccharo-1,4-lactone, a specific inhibitor of beta-glucuronidase, in the reaction mixture. The depolymerization of chondroitin by hyaluronidase was significantly reduced by the addition of saccharo-1,4-lactone. From the results, it is suggested that beta-glucuronidase contributes to the degradation of the even-numbered oligosaccharides which inhibit the action of hyaluronidase in the depolymerization of Ch4-S.