Stevens R L, Austen K F
J Biol Chem. 1982 Jan 10;257(1):253-9.
Rat serosal mast cells cultured in the presence of heat-inactivated fetal calf serum incorporated (35S) sulfate into heparin proteoglycan of approximately Mr = 750,000 after a 3-h pulse and a 2-h chase. beta-D-Xyloside (0.1 mM) treatments of cultures of rat mast cells resulted in an insignificant increase in total (35S) sulfate incorporation and the appearance of free glycosaminoglycans without a change in proteoglycan size. At higher beta-D-xyloside concentrations, total (35S)sulfate incorporation was inhibited and an increase in the relative glycosaminoglycan content was observed concomitant with a reduction in proteoglycan amount and size. As assessed by susceptibility to digestion by chondroitinase ABC, hydrolysis by nitrous acid, [3H]hexosamine content, and electrophoretic mobility, only heparin chains were polymerized onto the proteoglycan core in all cultures. In contrast, individual glycosaminoglycans which appeared only after beta-D-xyloside treatment were predominantly chondroitin sulfate rather than heparin, indicating that the beta-D-xyloside acceptor supported polymerization of chondroitin sulfate but not of heparin glycosaminoglycan. Thus, the peptide core is an important determinant for the synthesis of heparin glycosaminoglycan by rat peritoneal mast cells.
在热灭活胎牛血清存在的情况下培养的大鼠浆膜肥大细胞，经过3小时脉冲标记和2小时追踪后，将（35S）硫酸盐掺入到分子量约为750,000的肝素蛋白聚糖中。用β-D-木糖苷（0.1 mM）处理大鼠肥大细胞培养物，导致总（35S）硫酸盐掺入量无显著增加，且出现游离糖胺聚糖，而蛋白聚糖大小未改变。在较高的β-D-木糖苷浓度下，总（35S）硫酸盐掺入受到抑制，观察到糖胺聚糖相对含量增加，同时蛋白聚糖数量和大小减少。通过对软骨素酶ABC消化的敏感性、亚硝酸水解、[3H]己糖胺含量和电泳迁移率评估，在所有培养物中只有肝素链聚合到蛋白聚糖核心上。相比之下，仅在β-D-木糖苷处理后出现的单个糖胺聚糖主要是硫酸软骨素而非肝素，这表明β-D-木糖苷受体支持硫酸软骨素的聚合，但不支持肝素糖胺聚糖的聚合。因此，肽核心是大鼠腹膜肥大细胞合成肝素糖胺聚糖的重要决定因素。
