Fabbi M, Acuto O, Smart J E, Reinherz E L
Nature. 1984;312(5991):269-71. doi: 10.1038/312269a0.
Human T-cell receptors for antigen and major histocompatibility complex (MHC) determinants have now been defined on inducer, suppressor, and class 1 and class 2 MHC-specific cytotoxic T lymphocytes as T3-associated clonotypic molecules (Ti) of relative molecular mass 90,000 (90K) composed of one 49-54K alpha- and one 43K beta-subunit which are disulphide-linked. In the case of the Ti beta-subunit, N-terminal amino acid sequencing and molecular cloning techniques led recently to identification of the Ti beta-gene and showed that T-specific V, D, J and C segments fuse to form an active beta-gene. So far, however, there have been little structural data available on the Ti alpha-subunit. Here we have derived the amino acid sequence of a portion of the Ti alpha-subunit by CNBr fragmentation. Sequence analysis reveals approximately 40% homology between the Ti alpha-subunit fragment and the third framework of the variable region of immunoglobulin light and heavy chains, supporting the notion that the Ti alpha-subunit is a member of the immunoglobulin-Ti beta-gene family.
现已确定，在诱导性、抑制性以及1类和2类MHC特异性细胞毒性T淋巴细胞上，针对抗原和主要组织相容性复合体（MHC）决定簇的人类T细胞受体是与T3相关的克隆型分子（Ti），其相对分子质量为90,000（90K），由一个49 - 54K的α亚基和一个43K的β亚基通过二硫键连接而成。就Tiβ亚基而言，N端氨基酸测序和分子克隆技术最近导致了Tiβ基因的鉴定，并表明T特异性V、D、J和C片段融合形成一个活性β基因。然而，到目前为止，关于Tiα亚基几乎没有可用的结构数据。在这里，我们通过CNBr裂解获得了Tiα亚基一部分的氨基酸序列。序列分析揭示了Tiα亚基片段与免疫球蛋白轻链和重链可变区的第三个构架之间约40%的同源性，支持了Tiα亚基是免疫球蛋白 - Tiβ基因家族成员的观点。
