SWAP & SR PROTEIN REGULATION OF ALTERNATIVE SPLICING

糖基转移酶似乎具有高度的特异性，并且 结构特异性主要由低聚糖保留。 Tbus，从所描述的有限研究来看，残留物的 定位和连接遵循特定的模式和糖蛋白 异构性表示缺乏模式完备性。基础到 了解多聚糖的功能意义是一个详细的 场地特定的结构分析。为了解决第一个问题，我们 已经对蛋白质进行了葡聚糖相对分子质量分析 构建了LFA3和Ig G。LFA3TIP由第一个 淋巴细胞功能相关分子胞外区3 (LFA3)与人IgG1的铰链、CH2和CH3区融合。 通过N-连接的糖链的内切糖苷酶释放获得分析， 甲基化、电喷雾电离质量法提取 光谱和碰撞诱导分解(CID)。为了 测定神经氨基连接(例如，2-+3，与2-+6)，乳糖基 延伸，以及三天线分支位置，氧化，还原， 并对释放的多糖进行了甲基化(ORM) 转到ES-MS和CID酶促释药的初步评价 策略、甲基化和提取用电喷雾质谱(ESI MS)进行了评价 样品LFA3-A、LFA3-Al、LFA3113和LFA3 Pg (TS95RO275)和LFA3-B(TS95RO275)。这些研究表明， 末端糖不是随机分布在不同的 触角，但优先连接到特定的 N-乙酰乳糖胺残留量。此ESI MS质量配置文件包含所有 结构可以是信息量最大的，并且可以作为 结构查询，类似于碳水化合物组成分析。

Glycosyltransferases appear to be highly specific and the structural specificity is primarily retained by the oligosaccharide. Tbus, from the limited studies described, it appears that a residue's position and linkage follows a specific pattern and glycoprotein heterogeneity represents a lack of pattern completion. Fundamental to understanding glycan functional significance is a detailed site-specific structural analysis. To approach this first problem, we have undertaken glycan molecular weight profiles on the protein constructs LFA3 and IgG. LFA3TIP wasconstructed with the first extracellular domain of lymphocyte function-associated molecule 3 (LFA3) fused to the hinge, CH2, and CH3 regions of a human IgGl. Analyses were acquired by endoglycosidase release of N-linked glycans, methylation, and extraction using electrospray ionization mass spectrometry and collision-induced decomposition (CID). In order to determine neuraminyl linkages (e.g., 2-+3, vs. 2-+6), lactosyl extensions, and triantennary branched positions, oxidation, reduction, and methylation (ORM) were carried out on the released glycans prior to ES-MS and CID. Preliminary assessment of enzymatic release strategies, methylation and extraction were evaluated by ESI MS on samples LFA3-A, LFA3-Al, LFA3113, and LFA3 pg of sample each of LFA3-A (TS95RO275) and LFA3-B (TS95RO275). These studies have shown that the terminating sugars are not randomly distributed over the various antennae, but occur preferentially attached to specific N-acetyllactosamine residues. This ESI MS mass profile of all structures can be most informative and serves as a first level of structural inquiry, akin to carbohydrate composition analysis.