Robertson A M, Wright D P
School of Biological Sciences, University of Auckland, New Zealand.
Can J Gastroenterol. 1997 May-Jun;11(4):361-6. doi: 10.1155/1997/642360.
The presence of a high bacterial population in a region of the gastrointestinal tract is usually associated with the secretion of sulphomucins into the mucus gel covering that region. The term 'sulphomucin' is a histochemical description of the staining properties of mucin. At present this term can only be qualitatively related to the percentage of sulphate in the mucin molecule, which makes the term difficult to use in a biochemical and functional sense. Sulphomucins are thought to carry out the normal functions attributed to mucins; in addition, heavy sulphation rate-limits the degradation of mucins by bacterial mucin-degrading glycosidases. A number of mucin-specific glycosulphatases have been reported in bacteria, although only two such enzymes have been purified. These enzymes remove part of the sulphate content from sulphomucins and make them more susceptible to further enzymic degradation. The variety of chain locations and sugar attachment sites of sulphate esters on the mucin oligosaccharides, taken together with the data on the enzymes, suggest there will be a spectrum of bacterial glycosulphatases, with different properties, cellular locations and substrate specificities. Bacterial glycosulphatases have the potential to modify sulphated glycoconjugates at mucosal surfaces and should prove useful as biochemical tools for the study of sulphated glycoconjugates.
胃肠道某一区域存在高细菌数量通常与硫酸黏蛋白分泌到覆盖该区域的黏液凝胶中有关。术语“硫酸黏蛋白”是对黏蛋白染色特性的组织化学描述。目前，该术语仅能在质量上与黏蛋白分子中硫酸盐的百分比相关，这使得该术语在生化和功能意义上难以使用。硫酸黏蛋白被认为执行归因于黏蛋白的正常功能；此外，高硫酸化速率限制了细菌黏蛋白降解糖苷酶对黏蛋白的降解。细菌中已报道了多种黏蛋白特异性糖硫酸酯酶，尽管仅纯化了两种此类酶。这些酶从硫酸黏蛋白中去除部分硫酸盐含量，使其更易受到进一步的酶促降解。黏蛋白寡糖上硫酸酯的链位置和糖连接位点的多样性，连同有关这些酶的数据表明，将会有一系列具有不同特性、细胞定位和底物特异性的细菌糖硫酸酯酶。细菌糖硫酸酯酶有可能修饰黏膜表面的硫酸化糖缀合物，并且应被证明是研究硫酸化糖缀合物的有用生化工具。
