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Demonstration of frequent occurrence of oligosialic acid units in various glycoproteins

证明寡唾液酸单元在各种糖蛋白中频繁出现

基本信息

批准号：
10680581
负责人：
KITAJIMA Ken
金额：
$ 1.98万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

The objective of this research project were to demonstrate frequent ocurrence of oligosialic acid structure in glycoproteins and to elucidate their biological functions. The results follow :1. Development of specific probes for detecting various oligosialyl glycan structures : Three monoclonal antibodies were newly prepared (3G9 recognizing 8-O-sulfated Neu5Ac-containing oligosialic acid structures, 2A11 recognizing Neu5Acα→8Neu5Acα→6Glc, AC-1 (originally established by Dr. Keiko Nohara) recognizing oligo-N-glycolylneuraminic acid. Based on inhibition experiments and immunohistochemistry using these antibodies, a 2A11 epitope on sea urchin sperm was shown to mediate sperm-egg interaction.2. Identification and structural and biosynthetic studies of oligosialic acid-containing glycoproteins : Calf fetal serum fetuin, αィイD22ィエD2-macroglobulin and calf and murine Adipo Q (an adipocyte specific protein) were first identified as si/oligosialic acid glycoproteins. Expression of the oligosialyl structures Adipo Q in an adipocyte differentiating cell line increased as the cells were differentiated. Thus, oligosialic acid expression depends on differentiation.3. Examination of differentiation-dependent change of expression of oligosialic acid structures : Expression of oligosialic acid-containing glycoproteins in human premyelocytoma cell line HL60 was shown to change before and after differentiation. The expression of the oligosialyl epitope was also shown to change in adipose cell line before and after differentiation. Northern blot analysis using known α2,8-sialyltransferases cDNAs showed that no of these cDNAs were expressed in the cells, suggesting that novel member of the α2,8-sialyltransferases is expressed in the cell line.

本研究项目的目的是证明低聚硅酸结构在糖蛋白中的常见存在，并阐明其生物学功能。研究结果如下：1。新制备了3种单克隆抗体(3G9识别含有8- o-硫酸盐neu5ac的低聚糖酸结构，2A11识别Neu5Acα→8Neu5Acα→6Glc， AC-1（最初由Keiko Nohara博士建立）识别低聚n -糖基神经氨酸。基于这些抗体的抑制实验和免疫组化，发现海胆精子上的2A11表位介导了精卵相互作用。低聚硅酸糖蛋白的鉴定、结构和生物合成研究：犊牛胎儿血清胎蛋白、α γ γ γ γ γ γ γ -巨球蛋白、犊牛和小鼠Adipo Q（一种脂肪细胞特异性蛋白）首次被鉴定为si/低聚硅酸糖蛋白。脂肪细胞分化细胞系中寡聚结构Adipo Q的表达随着细胞的分化而增加。因此，低聚硅酸的表达依赖于分化。分化依赖性低聚硅酸结构表达变化的检测：人前髓细胞瘤细胞株HL60中含低聚硅酸糖蛋白的表达在分化前后发生变化。脂肪细胞系分化前后寡聚表位的表达也发生了变化。用已知的α2,8-唾液基转移酶cdna进行Northern blot分析，发现这些cdna在细胞中均未表达，提示在细胞系中表达了α2,8-唾液基转移酶的新成员。