Expression of Human Thyrotropin in Cell Lines with Different Glycosylation Patterns Combined with Mutagenesis of Specific Glycosylation Sites CHARACTERIZATION OF A NOVEL ROLE FOR THE OLIGOSACCHARIDES IN THE IN VITRO AND IN VIVO BIOACTIVITY

摘要: We used a novel approach to study the role of Asn-linked oligosaccharides for human thyrotropin (hTSH) activity. Mutagenesis Asn (N) within individual glycosylation recognition sequences Gln (Q) was combined with expression wild type and mutant hTSH in cell lines different patterns. The vitro activity lacking alpha 52 oligosaccharide (alpha Q52/TSH beta) expressed CHO-K1 cells (sialylated oligosaccharides) increased 6-fold compared type, whereas activities Q78/TSH beta alpha/TSH Q23 were 2-3-fold. Deletion also thyrotropic chorionic gonadotropin, contrast previous findings at its native receptor. CHO-LEC2 (sialic acid-deficient oligosaccharides), CHO-LEC1 (Man5GlcNAc2 intermediates), 293 (sulfated 5-8-fold higher than from cells. In cells, there no difference between selectively deglycosylated mutants these lines. Thus, hTSH, and, specifically, terminal sialic acid residues attenuate activity, previously reported stimulatory this chain gonadotropin follitropin Q52/CG suggests that receptor-related mechanisms may be responsible differences among glycoprotein hormones. Despite their beta, had faster serum disappearance rate decreased effect on T4 production mice. These highlight importance maintaining circulatory half-life hence vivo hTSH.