Endo M, Yamamoto M, Munakata H, Yamamoto R, Namiki O, Yosizawa Z
Tohoku J Exp Med. 1980 Aug;131(4):355-61. doi: 10.1620/tjem.131.355.
To elucidate precise chemical nature of urinary glycosaminoglycans (GAG), GAG in the seven major acidic subfractions in a previous paper (Endo et al. 1980a) were analyzed for the chemical compositions and studied on the linkage between carbohydrate and peptide. All the subfractions examined contained galactosamine, hexuronic acid as the major constituent sugars, and xylose, galactose, L-fucose as the minor ones. Some of the subfractions contained additional glucosamine. Sulfate was also found in all the subfractions as their major constituent. The contents of total amino acids ranged from 1.20 to 17.9%. Serine, threonine, aspartic acid, glutamic acid, glycine, alanine and leucine were found as major amino acids. Pronase digestion did not significantly change their molecular size. The presence of O-xylosyl-serine linkage between carbohydrate chains and peptide moieties ws verified byan alkali treatment. Nevertheless, the presence of small portions of galactose and xylose residues at the reducing ends of the carbohydrate chains suggested a possibility of exertion of endo-beta-galactosidase and endo-beta-xylosidase activities for the linkage regions.
为阐明尿糖胺聚糖（GAG）的确切化学性质，对前文（Endo等人，1980a）中七个主要酸性亚组分中的GAG进行了化学组成分析，并研究了碳水化合物与肽之间的连接。所有检测的亚组分均含有半乳糖胺、己糖醛酸作为主要组成糖，木糖、半乳糖、L-岩藻糖作为次要组成糖。一些亚组分还含有额外的葡萄糖胺。所有亚组分中也均发现有硫酸盐作为其主要成分。总氨基酸含量在1.20%至17.9%之间。丝氨酸、苏氨酸、天冬氨酸、谷氨酸、甘氨酸、丙氨酸和亮氨酸为主要氨基酸。链霉蛋白酶消化并未显著改变其分子大小。通过碱处理证实了碳水化合物链与肽部分之间存在O-木糖基丝氨酸连接。然而，碳水化合物链还原端存在少量半乳糖和木糖残基，这表明连接区域可能存在内切β-半乳糖苷酶和内切β-木糖苷酶活性。
