Gkonos P J, Charbonneau H, Lawson P T, Howard G A, Birnbaum R S, Roos B A
Medical Service, American Lake Veterans Administration Medical Center, Tacoma, WA 98493.
Peptides. 1989 Jan-Feb;10(1):137-43. doi: 10.1016/0196-9781(89)90090-9.
The biological significance of peptide hormone glycosylation is uncertain. To examine the effect of Asn-linked glycosylation on calcitonin's bioactivity we purified glycosylated calcitonin from a transplantable rat medullary thyroid carcinoma. Glycosylated calcitonin constituted 2.3% of the total extracted immunoreactive calcitonin. The structure of this peptide differed from nonglycosylated calcitonin only by the oligosaccharide modification of asparagine 3. Affinity of glycosylated calcitonin for lentil lectin indicated that the oligosaccharide was a complex processed form. In a standard in vivo bioassay glycosylated calcitonin had a markedly reduced hypocalcemic activity compared to nonglycosylated calcitonin, an effect most likely due to the presence of the oligosaccharide.
肽激素糖基化的生物学意义尚不确定。为了研究天冬酰胺连接的糖基化对降钙素生物活性的影响，我们从可移植的大鼠甲状腺髓样癌中纯化了糖基化降钙素。糖基化降钙素占总提取免疫反应性降钙素的2.3%。该肽的结构与非糖基化降钙素的不同之处仅在于天冬酰胺3的寡糖修饰。糖基化降钙素对扁豆凝集素的亲和力表明该寡糖是一种复杂的加工形式。在标准的体内生物测定中，与非糖基化降钙素相比，糖基化降钙素的降钙活性明显降低，这种效应很可能是由于寡糖的存在。
