X-RAY STRUCTURE OF LECTIN-GLYCAN COMPLEXES

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 来自蘑菇多孔菌（Polyporus squamosus）的多孔菌（Polyporus squamosus）凝集素（PSA）是一种28 kDa凝集素，其凝集人A、B和O以及兔红细胞。它绑定了- D-半乳糖苷，对N-聚糖的非还原末端Neu 5Ac-<$-（2，6）-Gal-<$-（1，4）-Glc/GlcNac（6-唾液酸化II型链）具有高特异性和亲和力。PSA对<$-（2，6）连接的唾液酸残基的严格特异性使其成为生物医学和糖生物学研究中有价值的工具。 PSA的结构及其与其配体的结合相互作用是未知的。PSA与已知蛋白质结构具有非常低的序列同源性。天然PSA晶体与配体6-唾液酸乳糖胺一起生长，X射线数据以1.7“分辨率收集。PSA的衍生重原子晶体正在生长，以帮助解决PSA的晶体结构。为了获得更多关于PSA糖识别结构域的信息，已经构建了截短的、活性的、C-末端缺失突变体（PSA-D1）。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Polyporus squamosus agglutinin (PSA) from mushroom Polyporus squamosus is a 28 kDa lectin which agglutinates human A, B, and O and rabbit red blood cells. It binds ¿-D-galactosides and exhibits high specificity and affinity towards nonreducing terminal Neu5Ac-¿-(2,6)-Gal-¿-(1,4)-Glc/GlcNac (6-sialylated type II chain) of N-glycans. The strict specificity of PSA for ¿-(2,6) linked sialic acid residues makes it a valuable tool in biomedical and glycobiological studies. The structure of PSA and its binding interaction with its ligand is unknown. PSA shares very low sequence homology with known protein structures. Native PSA crystals were grown with the ligand 6-sialyllactosamine and X-ray data were collected at 1.7 ¿ resolution. Derivative heavy atom crystals of PSA are being grown to help solve the crystal structure of PSA. To obtain more information about the carbohydrate recognition domain of PSA, a truncated, active, C-terminal deletion mutant (PSA-D1) has been constructed.