Fransson L A, Cöster L, Carlstedt I, Malmström A
Biochem J. 1985 Nov 1;231(3):683-7. doi: 10.1042/bj2310683.
Radiolabelled proteoheparan sulphates were isolated from confluent monolayers of fibroblasts and from their spent media. The cell-surface-associated proteoglycan (Mr 350 000) has a core protein of Mr 180 000 that is cleaved by reduction of disulphide bonds into polypeptides of Mr 90 000, both of which can bind transferrin [Fransson, Carlstedt, Cöster & Malmström (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 5657-5661]. Thrombin digestion of the proteoglycan yielded two major fragments. The larger one contained the heparan sulphate chains and glycoprotein-type oligosaccharides, whereas the smaller one contained interchain disulphide bond(s) and had affinity for transferrin as well as for octyl-Sepharose. The larger thrombic fragment was cleaved by trypsin into fragments containing the heparan sulphate chains and the oligosaccharides respectively. The smaller proteoheparan sulphate derived from the culture medium (Mr 150 000) had a core protein of Mr 30 000, which contained heparan sulphate-attachment and oligosaccharide-attachment regions, but no domains for binding of transferrin or for hydrophobic interactions.
从成纤维细胞汇合单层及其用过的培养基中分离出放射性标记的蛋白聚糖硫酸乙酰肝素。细胞表面相关蛋白聚糖（分子量350000）有一个分子量180000的核心蛋白，该核心蛋白通过二硫键还原被切割成分子量90000的多肽，这两种多肽都能结合转铁蛋白[弗兰松、卡尔施泰特、科斯特和马尔姆斯特伦（1984年）《美国国家科学院院刊》81，5657 - 5661]。凝血酶消化该蛋白聚糖产生两个主要片段。较大的片段包含硫酸乙酰肝素链和糖蛋白型寡糖，而较小的片段包含链间二硫键，对转铁蛋白以及辛基琼脂糖有亲和力。较大的凝血酶片段被胰蛋白酶切割成分别包含硫酸乙酰肝素链和寡糖的片段。源自培养基的较小蛋白聚糖硫酸乙酰肝素（分子量150000）有一个分子量30000的核心蛋白，该核心蛋白包含硫酸乙酰肝素连接区和寡糖连接区，但没有转铁蛋白结合结构域或疏水相互作用结构域。
