Schmidt G, Robenek H, Harrach B, Glössl J, Nolte V, Hörmann H, Richter H, Kresse H
J Cell Biol. 1987 Jun;104(6):1683-91. doi: 10.1083/jcb.104.6.1683.
Immunogold labeling was used to localize the core protein of small dermatan sulfate proteoglycan (DS-PG) on the surface of cultured human fibroblasts. At 4 degrees C, DS-PG core protein was uniformly distributed over the cell surface. At 37 degrees C, gold particles either became rearranged in form of clusters or remained associated with fibrils. Double-label immunocytochemistry indicated the co-distribution of DS-PG core protein and fibronectin in the fibrils. In an enzyme-linked immunosorbent assay, binding of DS-PG from fibroblast secretions and of its core protein to fibronectin occurred at pH 7.4 and at physiological ionic strength. Larger amounts of core protein than of intact proteoglycan could be bound. Fibronectin peptides containing either the heparin-binding domain near the COOH-terminal end or the heparin-binding NH2 terminus were the only fragments interacting with DS-PG and core protein. Competition and replacement experiments with heparin and dermatan sulfate suggested the existence of adjacent binding sites for heparin and DS-PG core protein. It is hypothesized that heparan sulfate proteoglycans and DS-PG may competitively interact with fibronectin.
免疫金标记法用于在培养的人成纤维细胞表面定位小硫酸皮肤素蛋白聚糖（DS-PG）的核心蛋白。在4℃时，DS-PG核心蛋白均匀分布于细胞表面。在37℃时，金颗粒要么以簇的形式重新排列，要么仍与原纤维相关联。双标记免疫细胞化学表明DS-PG核心蛋白和纤连蛋白在原纤维中共分布。在酶联免疫吸附测定中，来自成纤维细胞分泌物中的DS-PG及其核心蛋白与纤连蛋白的结合发生在pH 7.4和生理离子强度条件下。能结合的核心蛋白量比完整蛋白聚糖更多。含有COOH末端附近肝素结合结构域或肝素结合NH2末端的纤连蛋白肽是与DS-PG和核心蛋白相互作用的唯一片段。用肝素和硫酸皮肤素进行的竞争和置换实验表明存在肝素和DS-PG核心蛋白相邻的结合位点。据推测，硫酸乙酰肝素蛋白聚糖和DS-PG可能与纤连蛋白发生竞争性相互作用。
