MHCL RESTRICTED TCR RECOGNITION--STRUCTURAL BASIS

描述（改编自研究者摘要）：可溶性T细胞 受体（TCR）已经被工程化以用于由Lec3.2.8.1 CHO细胞分泌 其合成均质聚糖;亮氨酸拉链用于促进 A-B链关联 两种小鼠TCR，N15和N26，特异于囊泡 口腔炎病毒八肽（VSV 8）在Kb I类背景下 分子，已经通过这种方法表达。 N15和N26的晶体 与抗-Cb单克隆抗体（FabH 57）的Fab复合， 获得了N15-VSV_8/Kb和N26-VSV_8/Kb复合物。 的结构 N15-FabN 15复合物已通过分子解析法解析至2.8 A分辨率 与硒代甲硫氨酸/MAD定相结合的替换。 结构 将N15 TCR与其他IG超家族成员的TCR进行比较， 包括抗体、CD 4、VCAM-1和CD 2。 通过比较两个 在N15-FabH 57晶体的不对称单元中的复合物， 以确定V-V、V-C和/或C-C之间是否存在本征迁移率 TCR域。 将解析N15-VSV 8/Kb复合物的结构 通过使用分辨率为3 A的晶体进行分子置换。 将确定单个CDR在肽/MHC识别中的作用 并且通过比较结构分析抗原结合后的任何诱导的拟合 TCR-VSV 8/Kb与TCR-Fab复合物中CDR的差异。 结构分析 还将进行与VSV 8/Kb复合的N26 TCR的分析， 确定两种不同的TCR如何结合相同的肽/MHC配体。 这 应确定对接模式是固定的还是可变的，以及 特异性CDR和MHC之间的相互作用受到限制， 肽残基。

DESCRIPTION (Adapted from Investigator's abstract): Soluble T cell receptors (TCRs) have been engineered for secretion by Lec3.2.8.1 CHO cells which synthesize homogeneous gylcans; a leucine zipper is used to facilitate a-b chain association. Two mouse TCRs, N15 and N26, specific for vesicular stomatitis virus octapeptide (VSV8) in the context of the Kb class I molecule, have been expressed by this method. Crystals of N15 and N26 complexed with the Fab of an anti-Cb monoclonal antibody (FabH57) and of the N15-VSV8/Kb and N26-VSV8/Kb complexes have been obtained. The structure of the N15-FabN15 complex has been solved to 2.8 A resolution by molecular replacement in conjunction with selenomethionine/MAD phasing. The structure of the N15 TCR will be compared with that of other Ig superfamily members, including antibodies, CD4, VCAM-1 and CD2. By comparing each of two complexes in the asymmetric unit of N15-FabH57 crystals, it may be possible to ascertain whether there is intrinsic mobility between V-V, V-C and/or C-C domains of the TCR. The structure of the N15-VSV8/Kb complex will be solved by molecular replacement using crystals which diffract to 3 A resolution. The role of individual CDRs in peptide/MHC recognition will be determined and any induced fit upon antigen binding analyzed by comparing the structure of the CDRs in the TCR-VSV8/Kb versus TCR-Fab complex. Structure analysis of the N26 TCR complexed with VSV8/Kb will also be carried out in order to determine how two different TCRs bind the same peptide/MHC ligand. This should establish whether the docking mode is fixed or variable and whether there are restricted interactions between specific CDRs and MHC versus peptide residues.