Moseley J M, Findlay D M, Gorman J J, Michelangeli V P, Martin T J
Biochem J. 1983 Jun 15;212(3):609-16. doi: 10.1042/bj2120609.
The glycosyl nature of the receptor for the peptide hormone calcitonin has been investigated in a human breast cancer cell line, T 47D. Studies have been carried out to assess the ability of various lectins and of the antibiotic tunicamycin to inhibit specific binding of calcitonin to the cells, to reduce cross-linking of photoactive calcitonin to a macromolecular receptor component and to influence calcitonin stimulation of cyclic AMP. Pre-incubation of cells with low concentrations of tunicamycin for 72 h resulted in a reduction of total specific binding by approx. 80% and a 40% reduction in calcitonin-stimulated adenylate cyclase; formation of the cross-linked receptor component was also inhibited. Wheat-germ lectin showed the most marked inhibition of total specific binding and cyclic AMP production. However, cross-linking of photoactive calcitonin to receptor component was totally inhibited by this lectin. Soya-bean lectin brought about very little reduction in total specific binding but had more profound effects on calcitonin-stimulated cyclic AMP production and cross-linking of photoactive calcitonin. Concanavalin A and lentil lectin showed some inhibition of all parameters. The data indicate that the calcitonin receptor in T 47D cells is associated with glycosyl moieties, the major contributors of which are N-acetyl-D-glucosamine residues, but N-acetyl-D-galactosamine and mannose residues are also associated.
在人乳腺癌细胞系T 47D中，对肽激素降钙素受体的糖基性质进行了研究。已开展多项研究，以评估各种凝集素和抗生素衣霉素抑制降钙素与细胞特异性结合的能力、减少光活性降钙素与大分子受体成分的交联以及影响降钙素对环磷酸腺苷（cAMP）的刺激作用。用低浓度衣霉素对细胞进行72小时预孵育，导致总特异性结合减少约80%，降钙素刺激的腺苷酸环化酶减少40%；交联受体成分的形成也受到抑制。麦胚凝集素对总特异性结合和cAMP产生的抑制作用最为显著。然而，这种凝集素完全抑制了光活性降钙素与受体成分的交联。大豆凝集素对总特异性结合的降低作用很小，但对降钙素刺激的cAMP产生和光活性降钙素的交联有更显著的影响。伴刀豆球蛋白A和扁豆凝集素对所有参数均有一定程度的抑制作用。数据表明，T 47D细胞中的降钙素受体与糖基部分相关，其中主要贡献者是N-乙酰-D-葡萄糖胺残基，但N-乙酰-D-半乳糖胺和甘露糖残基也与之相关。
