Weisz O A, Schnaar R L
Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Biochem Biophys Res Commun. 1990 Feb 28;167(1):67-73. doi: 10.1016/0006-291x(90)91731-7.
Freshly isolated chicken and rat hepatocytes adhere with carbohydrate specificity to surfaces derivatized with N-acetylglucosamine and galactose respectively. Previously (Brandley, B.K. and Schnaar, R.L. (1985) J. Biol. Chem. 260, 12474-12483) we reported that metabolically radiolabeled chicken hepatocytes covalently transferred phosphate radiolabel specifically to N-acetylglucosamine-derivatized surfaces. We now report that rat hepatocytes transfer phosphate radiolabel specifically to galactose-derivatized surfaces. Transferred radiolabel from both species to their appropriate carbohydrate-derivatized surface was identified as CoASH. After specific adhesion via the appropriate carbohydrate, CoASH is apparently released from cells and undergoes disulfide exchange with the cleavable immobilization linker we used to tether the sugars to the artificial surfaces. Although CoASH from lysed cells can undergo similar disulfide exchange, the data suggest that other, perhaps physiological mechanisms may be responsible for the carbohydrate-specific radiolabel transfer.
新鲜分离的鸡和大鼠肝细胞分别以碳水化合物特异性方式粘附于用N-乙酰葡糖胺和半乳糖衍生化的表面。之前（布兰德利，B.K.和施纳尔，R.L.（1985年）《生物化学杂志》260卷，12474 - 12483页）我们报道，经代谢放射性标记的鸡肝细胞将磷酸放射性标记特异性共价转移至N-乙酰葡糖胺衍生化的表面。我们现在报道，大鼠肝细胞将磷酸放射性标记特异性转移至半乳糖衍生化的表面。从这两个物种转移至其相应碳水化合物衍生化表面的放射性标记被鉴定为辅酶A（CoASH）。通过相应碳水化合物进行特异性粘附后，CoASH显然从细胞中释放出来，并与我们用于将糖类连接到人工表面的可裂解固定连接子进行二硫键交换。尽管来自裂解细胞的CoASH可进行类似的二硫键交换，但数据表明其他可能的生理机制或许是碳水化合物特异性放射性标记转移的原因。
