Quill H, Hoffman M D, Thomas D W, Schwartz B D
Mol Immunol. 1982 Dec;19(12):1587-1602. doi: 10.1016/0161-5890(82)90270-x.
A xenoantiserum raised in rabbits by immunization with strain 13 guinea-pig antigen-activated T-lymphocytes was previously found to recognize a non-immunoglobulin, 75,000 mol. wt glycoprotein synthesized by guinea-pig T-cells. This protein, p75, has been further characterized to determine its biochemical properties and its expression by various cell types. p75 was found to be a single-chain protein which could be bound by the lectin Lens culinaris hemagglutinin. It has an apparent mol. wt slightly greater than mu-chain as assessed by SDS-polyacrylamide gel electrophoresis and could not be precipitated by anti-guinea-pig immunoglobulin reagents. It exhibited considerable charge heterogeneity during isoelectric focusing and was not affected by neuraminidase treatment, p75 was synthesized by thymus, spleen and lymph node cells, by antigen-stimulated T-cells from strain 13 and strain 2 guinea-pigs, and by guinea-pig B-cell L2C leukemia lines, but not by normal B-lymphocytes or macrophages. No differences between the isoelectric focusing patterns of p75 molecules isolated from different cell types could be demonstrated. The chemical properties of p75 and its expression by the cell types so far examined indicate that p75 is a possible candidate for the guinea-pig homologue of the murine Lyt-1 antigen.
先前发现，用13型豚鼠抗原激活的T淋巴细胞免疫家兔所产生的异种抗血清能识别一种由豚鼠T细胞合成的非免疫球蛋白、分子量为75,000的糖蛋白。这种蛋白，即p75，已进一步进行特性分析，以确定其生化特性以及在各种细胞类型中的表达情况。发现p75是一种单链蛋白，可被凝集素扁豆血凝素结合。通过SDS-聚丙烯酰胺凝胶电泳评估，其表观分子量略大于μ链，且不能被抗豚鼠免疫球蛋白试剂沉淀。在等电聚焦过程中，它表现出相当大的电荷异质性，且不受神经氨酸酶处理的影响。p75由胸腺、脾脏和淋巴结细胞、来自13型和2型豚鼠的抗原刺激T细胞以及豚鼠B细胞L2C白血病系合成，但正常B淋巴细胞或巨噬细胞不合成。从不同细胞类型分离的p75分子的等电聚焦图谱之间未显示出差异。p75的化学特性及其在目前所检测细胞类型中的表达表明，p75可能是小鼠Lyt-1抗原的豚鼠同源物的候选者。
