Effects of Microbiol polysaccharides on cancer metastasis

我们正在研究糖的生物学功能及其与疾病的关系。聚唾液酸除了作为N-CAM的一个组成部分的功能外，还被认为与癌症转移有关。因此，我们从大肠杆菌噬菌体中纯化了唾液酸化酶，并克隆了该酶的基因。该酶是一种独特的内切唾液酸酶，其最小底物为唾液酸三聚体，聚唾液酸的最终产物为唾液酸二聚体。该酶为同四聚体，由120 Kd亚基组成。我们还研究了具有唾液酸乳糖胺聚合物的无乳链球菌的芙膜多糖。唾液酸乳糖胺是结合L-选择的唾液酸刘易斯糖的类似物。因此，我们研究了这种糖的功能，通过使用抗L-选择抗体。我们发现该抗体通过升高细胞内钙离子浓度诱导T淋巴细胞聚集。我们还发现，通过葡萄球菌超抗原刺激的T细胞生长被抗选择素抗体增强。

We are studying biological functions of sugar and its relation to disease. Polysialic acid is suggested to relate cancer-metastasis in addition to the function as a component of N-CAM.We therefore purified sialydase from a coliphage and cloned the enzyme gene. This sialydase was unique as endosialydase, since minimun substrate size was sialyltrimer and the final product from polysialic acid was sialyldimer. The enzyme was homotetramer and composed of 120 Kd subunit.We also studied the capsular polysaccharide of Streptococcus agalactiae which has sialyl lactosamine polymer. Sialyl lactosamine is an analog of sialyl Lewis sugar which binds L-selection. We therefore studied the function of this sugar by using anti-L-selection antibody. We found that the antibody induced the aggregation of T-lymphocytes by elevating intracellular calcium concentration. We also found that T-cell growth by the stimulation of staphyrococcul superantigen was enhanced by anti-selectin antibody.