Identification and partial characterization of three low-molecular-weight collagenous polypeptides synthesized by chondrocytes cultured within collagen gels in the absence and in the presence of fibronectin.
Identification and partial characterization of three low-molecular-weight collagenous polypeptides synthesized by chondrocytes cultured within collagen gels in the absence and in the presence of fibronectin.
复制标题
对在不存在和存在纤连蛋白的情况下在胶原凝胶内培养的软骨细胞合成的三种低分子量胶原多肽的鉴定和部分表征。
作者：
Gary J. Gibson;T. C. M. Kielty;Clare Garner;Seth L. SCHORt;M. E. Grant
三维胶原凝胶内培养鸡胚胸骨软骨细胞促进三种低分子量胶原多肽的合成。血清补充剂中是否存在纤连蛋白显着影响合成并释放到培养基中的这些新型胶原蛋白的比例。在塑料培养皿上培养的软骨细胞似乎只能合成少量的这些低分子量物质。这三个物种（指定为G，H和J）的特点是相对于[14 C]脯氨酸掺入到每种多肽中的羟基[14 C]脯氨酸的比例，并就其对细菌胶原酶的亲和性。根据还原条件下的电泳迁移率，计算出G、H和J多肽的Mr分别为59 000、69 000和84 000。糜蛋白酶消化转化成一个物种的G胶原蛋白含有多肽的Mr 45 000，而H和J多肽产生了一个单一的带的Mr 53 000。发现H和J多肽作为二硫键连接的聚集体出现，胰凝乳蛋白酶消化产物也是如此。肽“图谱”显示G、H和J多肽没有显示共同的同一性，并且与已知的间质胶原不同。天然G胶原蛋白被人胶原酶消化成离散产物，而H和J链在相同条件下不被切割。
Culture of chick-embryo sternal-cartilage chondrocytes within three-dimensional collagen gels promotes the synthesis of three low-molecular-weight collagenous polypeptides. The proportions of these novel collagens synthesized and released into the medium are markedly influenced by the presence or the absence of fibronectin in the serum supplement. Chondrocytes cultured on plastic dishes appear to synthesize only small amounts of these low-molecular-weight species. The three species (designated G, H and J) were characterized with respect to the proportion of [14C]proline incorporated into each polypeptide occurring as hydroxy[14C]proline and with respect to their susceptibilities to bacterial collagenase. On the basis of their electrophoretic mobilities under reducing conditions, the G, H and J polypeptides were calculated to have Mr 59 000, 69 000 and 84 000 respectively. Chymotrypsin digestion converted the G collagen into a species containing polypeptides of Mr 45 000, whereas the H and J polypeptides yielded a single band of Mr 53 000. The H and J polypeptides were found to occur as disulphide-linked aggregates, as was the chymotrypsin-digestion product. Peptide 'mapping' has shown that G, H and J polypeptides show no common identity and are distinct from the known interstitial collagens. Native G collagen was digested by human collagenase to discrete products, whereas H and J chains were not cleaved under identical conditions.