Sakurai S, Fogelfeld L, Ries A, Schneider A B
Department of Medicine, Michael Reese Hospital and Medical Center, University of Illinois, Chicago 60616.
Endocrinology. 1990 Nov;127(5):2056-63. doi: 10.1210/endo-127-5-2056.
Human thyroglobulin (hTG) contains sulfate in chondroitin 6-sulfate chains and in complex carbohydrates. In this study the sulfate-containing complex carbohydrates were characterized by the number of sulfate and sialic acid residues that they contain. Samples of normal and nodular thyroid tissue were incubated for 16 h in [35S]sulfate-containing medium, and hTG was purified from the tissues and the media. Complex carbohydrates were enzymatically removed from hTG. Subsequent analysis on an HPLC anion exchange column at pH 2.2 separated the carbohydrate units according to their number of negative charges. Sulfate-containing peaks were monitored by radioactivity, and sialic acid-containing peaks were identified by their shift to lower charge after treatment with neuraminidase. Peaks corresponding to sialic acid-free carbohydrate units with one to four sulfates were identified. Also, carbohydrate units with two and three negative charges containing both sulfate and sialic acid were present. In the nodular tissue of one patient there were more sulfated units with higher charge, especially units containing sialic acid. In this patient the proportion of sulfated polyvalent units with sialic acid was 22.4% for normal and 64.6% for nodular tissue. No difference in the composition of the charged units between the tissues and their corresponding media was seen, making it unlikely that the sulfate-containing carbohydrates play a role in hTG release. It is concluded that hTG contains complex carbohydrate units with up to four sulfate groups and units with both sulfate and sialic acid. In some patients, the sulfate-containing anionic carbohydrate units of hTG from normal and nodular thyroid tissue are different.
人甲状腺球蛋白（hTG）在硫酸软骨素6 - 硫酸酯链和复合碳水化合物中含有硫酸盐。在本研究中，含硫酸盐的复合碳水化合物通过其所含硫酸盐和唾液酸残基的数量来表征。将正常和结节性甲状腺组织样本在含[35S]硫酸盐的培养基中孵育16小时，然后从组织和培养基中纯化hTG。通过酶法从hTG中去除复合碳水化合物。随后在pH 2.2的HPLC阴离子交换柱上进行分析，根据碳水化合物单元的负电荷数量将其分离。通过放射性监测含硫酸盐的峰，并用神经氨酸酶处理后，根据其电荷向更低值的移动来鉴定含唾液酸的峰。鉴定出对应于不含唾液酸且含有一至四个硫酸盐的碳水化合物单元的峰。此外，还存在同时含有硫酸盐和唾液酸且带有两个和三个负电荷的碳水化合物单元。在一名患者的结节组织中，带有更高电荷的硫酸化单元更多，尤其是含有唾液酸的单元。在该患者中，含唾液酸的硫酸化多价单元在正常组织中的比例为22.4%，在结节组织中的比例为64.6%。未观察到组织与其相应培养基中带电单元组成的差异，这使得含硫酸盐的碳水化合物不太可能在hTG释放中起作用。结论是，hTG含有多达四个硫酸基团的复合碳水化合物单元以及同时含有硫酸盐和唾液酸的单元。在一些患者中，来自正常和结节性甲状腺组织的hTG的含硫酸盐阴离子碳水化合物单元有所不同。
