CHAR OF GLYCANS FROM MOUSE & BOVINE UROPLAKINS IA & IB BY MASS SPECTROMETRY

来自小鼠的聚糖的字符

基本信息

批准号：
7722979
负责人：
Tung-Tien Sun
金额：
$ 2.59万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-06-01 至 2009-05-31
项目状态：
已结题

项目摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Although it has been shown that mouse uroplakin (UP) Ia, a major glycoprotein of urothelial apical surface, can serve as the receptor for the FimH lectin adhesin of type 1-fimbriated E. coli, the organism which causes a great majority of urinary tract infections (UTIs), the glycan structure of this native receptor was unknown. Using a sensitive approach that combines in-gel glycosidase and protease digestions, permethylation of released glycans and mass spectrometry, we have elucidated, for the first time, the native glycoform structures of the mouse UPIa receptor and those of its non-binding homolog, UPIb, and have determined the glycosylation site occupancy. UPIa presents a high level of terminally exposed mannose residues (located on Man6GlcNAc2 to Man9GlcNAc2) that are capable of specifically interacting with FimH. We have shown that this property is conserved, not only in the mouse uroplakins, but also in cattle and, even more importantly, in human UPIa, thus establishing the concept that UPIa is a major urothelial receptor in humans and other mammals for the mannose-specific FimH variant. In contrast, our results indicate that most terminally exposed glycans of mouse UPIb are non-mannose residues, thus explaining the failure of FimH to bind to this UPIb. In cattle, on the other hand, complex carbohydrates constituted only about 20% of the UPIb N-linked glycans. Human UPIa contained exclusively high-mannose glycans and human UPIb contained only complex glycans. The drastically different carbohydrate processing of the UPIa and UPIb proteins, two closely related members of the tetraspanin family, may reflect differences in their folding and masking due to their interactions with their associated proteins, UPII and UPIIIa, respectively. Results from this study shed light on the molecular pathogenesis of UTIs and may aid in the design of glyco-mimetic inhibitors for preventing and treating this disease.

该副本是利用众多研究子项目之一由NIH/NCRR资助的中心赠款提供的资源。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此，可以在其他清晰的条目中表示。列出的机构是对于中心，这不一定是调查员的机构。尽管已经表明，小鼠尿布链蛋白（UP）ia是尿路上皮顶表面的主要糖蛋白，可以用作1型1型大肠杆菌的FIMH凝集素粘附蛋白的受体，这是导致绝大多数尿裂纹的生物体感染（UTI），该天然受体的聚糖结构尚不清楚。使用一种敏感的方法，将凝胶内糖苷酶和蛋白酶消化，释放的聚糖和质谱法的苄苄氨基化，我们首次阐明了小鼠UPIA受体的天然糖型结构及其非约束同源物的天然糖型结构，并确定了糖基化位点的占用率。 UPIA提出了能够与FIMH专门相互作用的高末端暴露的甘露糖残基（位于MAN6GLCNAC2上）。我们已经表明，这种特性不仅是保守的，不仅在小鼠乌拉蓝蛋白中，而且在牛，甚至更重要的是在人类的Upia中，因此确定了upia是人类中的主要尿路上皮受体，而其他哺乳动物则是mannose-的其他哺乳动物。特定的FIMH变体。相比之下，我们的结果表明，大多数终末暴露的小鼠UPIB聚糖是非甘露糖残基，因此解释了FIMH与该UPIB结合的失败。另一方面，在牛中，复杂的碳水化合物仅构成约20％的UPIB N连接聚糖。人类UPIA仅包含高甘露糖的聚糖，而人UPIB仅包含复杂的聚糖。 UPIA和UPIB蛋白的碳水化合物加工截然不同，这是四叠腺苷家族的两个密切相关的成员，可能反映出由于它们与相关蛋白，UPII和UPIIIA的相互作用，它们的折叠和掩饰差异差异。这项研究的结果阐明了UTI的分子发病机理，并可能有助于设计用于预防和治疗该疾病的糖仿真抑制剂。