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

来自小鼠的聚糖的字符

• 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
• 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
• 来源: https://reporter.nih.gov/project-details/7722979
• 关键词: Apical; Bacterial Adhesins; Binding; Bos taurus; Carbohydrates; Cattle; Complex; Computer Retrieval of Information on Scientific Projects Database; Digestion; Disease; Endopeptidases; Escherichia coli; Failure; Family; Funding; Gel; Glycoproteins; Glycoside Hydrolases; Grant; Hand; Homologous Gene; Human; Institution; Lectin; Light; Link; Mammals; Mannose; Masks; Mass Spectrum Analysis; Molecular; Mus; Organism; Pathogenesis; Peptide Hydrolases; Polysaccharides; Process; Property; Proteins; Research; Research Personnel; Resources; Site; Source; Structure; Surface; Time; United States National Institutes of Health; Urinary tract infection; Variant; concept; design; glycosylation; human PHEMX protein; inhibitor/antagonist; mannosyl(6)-N-acetyl(2)glucose; mannosyl(9)-N-acetylglucosamine2; member; mimetics; prevent; receptor

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.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 虽然已经证明，小鼠尿斑蛋白（UP）Ia，尿路上皮顶端表面的主要糖蛋白，可以作为1型菌毛大肠杆菌FimH凝集素粘附素的受体。大肠杆菌是引起大多数尿路感染（UTIs）的生物体，这种天然受体的聚糖结构是未知的。使用一个敏感的方法，结合凝胶内糖苷酶和蛋白酶diglysine，permethylation释放的聚糖和质谱，我们已经阐明，第一次，小鼠UPIA受体的天然糖型结构和其非结合同系物，UPIB，并已确定的糖基化位点占用。UPIa呈现高水平的末端暴露的甘露糖残基（位于Man 6 GlcNAc 2至Man 9 GlcNAc 2上），其能够与FimH特异性相互作用。我们已经表明，这种性质是保守的，不仅在小鼠尿斑蛋白，而且在牛，甚至更重要的是，在人的UPIA，从而建立的概念，UPIA是一个主要的尿路上皮受体在人类和其他哺乳动物的甘露糖特异性FimH变体。相比之下，我们的结果表明，小鼠UPIb的大多数末端暴露的聚糖是非甘露糖残基，从而解释了FimH未能结合该UPIb。另一方面，在牛中，复合碳水化合物仅占UPIb N-连接聚糖的约20%。人UPIa仅含高甘露糖聚糖，人UPIb仅含复合聚糖。非常不同的碳水化合物处理的UPIa和UPIb蛋白，两个密切相关的四跨膜蛋白家族的成员，可能反映了他们的折叠和掩蔽的差异，由于其相互作用与其相关的蛋白质，UPII和UPIIIa，分别。这项研究的结果揭示了尿路感染的分子发病机制，并可能有助于设计糖模拟抑制剂预防和治疗这种疾病。