Macromolecular insoluble cold globulin (MICG): a novel protein from mouse lymphocytes. IV. Evidence for the plasma membrane distribution of MICG.
Macromolecular insoluble cold globulin (MICG): a novel protein from mouse lymphocytes. IV. Evidence for the plasma membrane distribution of MICG.
复制标题
大分子不溶性冷球蛋白（MICG）：一种来自小鼠淋巴细胞的新型蛋白质。
作者：
S. Hauptman;E. Kansu;S. Godfrey
大分子不溶性冷球蛋白是主要由小鼠T淋巴细胞合成的糖蛋白。本报告详细介绍了证明 MICG 在 T 淋巴细胞质膜上分布的实验。利用免疫荧光技术表明，MICG位于98%的胸腺淋巴细胞和60%的脾淋巴细胞的外细胞表面。此外，在脾细胞中，已证明 T 细胞而非 B 细胞表面 MICG 呈阳性。 MICG 抗体能够覆盖所有免疫荧光阳性 (60%) 的脾细胞。相反，抗MICG抗体不诱导胸腺细胞上帽的形成。仅当使用稀释的抗体溶液时，MICG 才会覆盖胸腺细胞。通过对胸腺和脾细胞进行有限的蛋白水解，MICG 可在 T 细胞表面再生，半衰期为 3.5 小时。 MICG 的分布和细胞表面特征根据该蛋白质的“受体样”功能进行讨论。
Macromolecular insoluble cold globulin is a glycoprotein synthesized predominantly by T lymphocytes in the mouse. The present report details experiments demonstrating the plasma membrane distribution of MICG on T lymphocytes. By utilizing immunofluorescent techniques it was shown that MICG was located in the external cell surface of 98% of thymic lymphocytes and 60% of splenic lymphocytes. Furthermore, in spleen cells, it was demonstrated that T cells and not B cells were surface MICG positive. Antibody to MICG was able to cap all of the immunofluorescent-positive (60%) spleen cells. In contrast, anti-MICG antibody did not induce cap formation on thymus cells. Only when dilute solutions of antibody were used did MICG cap on the thymus cells. Employing limited proteolysis of thymus and spleen cells MICG was shown to be regenerated on the surface of T cells with a half-life of 3.5 hr. The distribution and cell surface characteristics of MICG are discussed in terms of a "receptor-like" function for this protein.