Mannik M, Person R E
Department of Medicine, University of Washington, Seattle 98195.
Rheumatol Int. 1993;13(3):121-9. doi: 10.1007/BF00290300.
The present study was undertaken to identify the cartilage matrix molecules that are bound with intermolecular disulfide bonds to IgG and serum albumin molecules recovered from the articular cartilage of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). The cartilage specimens were extracted sequentially with three changes of neutral buffer, three changes of 6 M guanidine hydrochloride and then partially degraded with bacterial collagenase. The extracted IgG and albumin, along with matrix molecules bound to these proteins, were isolated with affinity chromatography using antibodies to IgG or human serum albumin conjugated to agarose beads. The isolated materials were characterized with sodium dodecyl sulfate polyacrylamide gel electrophoresis and transfer blotting, using specific antibodies to IgG, albumin, and proteoglycans. In the isolated materials, heteropolymers with IgG or albumin were identified. These polymers contained keratan sulfate and less frequently chondroitin-4-sulfate and chondroitin-6-sulfate. These findings identified the keratan sulfate rich proteoglycans, prevalent at the surface of joint cartilage, as the most common cartilage matrix molecules that are covalently bound to IgG or to serum albumin by disulfide bonds in the articular cartilage of patients with RA or OA.
本研究旨在鉴定类风湿性关节炎（RA）或骨关节炎（OA）患者关节软骨中与免疫球蛋白G（IgG）和血清白蛋白分子通过分子间二硫键结合的软骨基质分子。用三种不同的中性缓冲液依次提取软骨标本，再用三种不同的6M盐酸胍提取，然后用细菌胶原酶进行部分降解。使用与琼脂糖珠偶联的抗IgG或人血清白蛋白抗体，通过亲和色谱法分离提取的IgG和白蛋白，以及与这些蛋白质结合的基质分子。使用抗IgG、白蛋白和蛋白聚糖的特异性抗体，通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳和转印杂交对分离出的物质进行表征。在分离出的物质中，鉴定出了与IgG或白蛋白结合的杂聚物。这些聚合物含有硫酸角质素，较少含有硫酸软骨素-4和硫酸软骨素-6。这些发现表明，在关节软骨表面普遍存在的富含硫酸角质素的蛋白聚糖，是RA或OA患者关节软骨中通过二硫键与IgG或血清白蛋白共价结合的最常见软骨基质分子。
