Funderburgh J L, Caterson B, Conrad G W
J Biol Chem. 1987 Aug 25;262(24):11634-40.
Three antibodies reacting with corneal keratan sulfate proteoglycan were used to detect antigenically related molecules in 11 bovine and 13 embryonic chick tissues. Two monoclonal antibodies recognized sulfated epitopes on the keratan sulfate chain and a polyclonal antibody bound antigenic sites on the core protein of corneal keratan sulfate proteoglycan. Competitive immunoassay detected core protein and keratan sulfate antigens in guanidine HCl extracts of most tissues. Keratan sulfate antigens of most bovine tissues were only partially extracted with guanidine HCl, but the remainder could be solubilized by CNBr treatment of the guanidine-extracted residue. Keratan sulfate and core protein antigens co-eluted with purified corneal keratan sulfate proteoglycan on ion exchange high-performance liquid chromatography (HPLC). Endo-beta-galactosidase digestion of the HPLC-purified keratan sulfate antigens eliminated the binding of monoclonal anti-keratan sulfate antibodies in enzyme-linked immunosorbent assay. Extracts of all 11 bovine tissues, except those from brain and cartilage, could bind both anti-keratan sulfate monoclonal antibodies and anti-core protein polyclonal antibody simultaneously. Binding was sensitive to competition with keratan sulfate and to digestion with endo-beta-galactosidase. These results suggest widespread occurrence of a proteoglycan or sulfated glycoprotein bearing keratan sulfate-like carbohydrate and a core protein resembling that of corneal keratan sulfate proteoglycan.
使用三种与角膜硫酸角质素蛋白聚糖发生反应的抗体，检测11种牛组织和13种鸡胚胎组织中的抗原相关分子。两种单克隆抗体识别硫酸角质素链上的硫酸化表位，一种多克隆抗体结合角膜硫酸角质素蛋白聚糖核心蛋白上的抗原位点。竞争性免疫测定法在大多数组织的盐酸胍提取物中检测到核心蛋白和硫酸角质素抗原。大多数牛组织的硫酸角质素抗原仅部分能用盐酸胍提取，但其余部分可通过对胍提取残渣进行溴化氰处理来溶解。在离子交换高效液相色谱（HPLC）上，硫酸角质素和核心蛋白抗原与纯化的角膜硫酸角质素蛋白聚糖共洗脱。对HPLC纯化的硫酸角质素抗原进行内切β-半乳糖苷酶消化，消除了酶联免疫吸附测定中抗硫酸角质素单克隆抗体的结合。除了来自脑和软骨的组织外，所有11种牛组织的提取物都能同时结合抗硫酸角质素单克隆抗体和抗核心蛋白多克隆抗体。这种结合对与硫酸角质素的竞争和内切β-半乳糖苷酶的消化敏感。这些结果表明，广泛存在一种带有硫酸角质素样碳水化合物和类似于角膜硫酸角质素蛋白聚糖核心蛋白的核心蛋白的蛋白聚糖或硫酸化糖蛋白。
