Engvall E, Bell M L, Carlsson R N, Miller E J, Ruoslahti E
Cell. 1982 Jun;29(2):475-82. doi: 10.1016/0092-8674(82)90164-7.
A novel method of affinity chromatography on insolubilized collagen-binding fragments of fibronectin was utilized to isolate a random-coil collagenous protein from culture media of mouse teratocarcinoma-derived endodermal cells. These cells also produced another collagenous protein, which did not bind to fibronectin but could be isolated by differential salt precipitation. The affinity-purified collagen differs from its conventionally isolated counterpart in that it is not triple-helical in structure, its polypeptides are not disulfide-crosslinked and it has affinity for fibronectin in its native state. Both collagens resemble previously characterized type IV basement-membrane collagens with respect to their amino acid composition, cyanogen bromide peptides, chain size, immunological reactivity and tissue localization. The random-coil collagen is directly active in promoting the attachment of some lines of cells, but for attachment of the endodermal cells addition of fibronectin is required. This suggests that the presence of nonhelical, fibronectin-binding collagen may have biological significance in the interaction of cells with the extracellular matrix.
利用一种新的亲和色谱方法，以固定化的纤连蛋白胶原结合片段为介质，从小鼠畸胎瘤衍生的内胚层细胞培养基中分离出一种无规卷曲的胶原蛋白质。这些细胞还产生了另一种胶原蛋白质，它不与纤连蛋白结合，但可通过分级盐沉淀法分离出来。亲和纯化的胶原与其传统分离的对应物不同，其结构不是三螺旋的，其多肽不是通过二硫键交联的，并且在天然状态下对纤连蛋白具有亲和力。就氨基酸组成、溴化氰肽、链大小、免疫反应性和组织定位而言，这两种胶原均类似于先前鉴定的IV型基底膜胶原。无规卷曲的胶原在促进某些细胞系的附着方面具有直接活性，但对于内胚层细胞的附着，则需要添加纤连蛋白。这表明非螺旋的、与纤连蛋白结合的胶原的存在可能在细胞与细胞外基质的相互作用中具有生物学意义。
