NEW HIGH MOLECULAR WEIGHT EXTRACELLULAR MATRIX PROTEIN

在研究细胞外基质合成的过程中， 儿时的肿瘤，我们曾经遇到过一种以前无法确定的， 高分子量(500,000 D)蛋白质分泌到细胞内 几种肿瘤细胞系的条件培养液。这种蛋白质是 与层粘连蛋白、IV型胶原有关的分泌，以及 纤维连接蛋白，但在免疫学上与之不同。它也是 与基底膜蛋白多糖抗体无反应。它失败了 用放射性标记的硫酸钠或糖基前体标记， 这进一步将其与传统的蛋白多糖区分开来。 选择性酶降解研究表明，这种蛋白质 对胰酶和胃酶敏感，但胶原酶和GAG降解 酶不敏感。旋转阴影的超微结构研究， 纯化的分子揭示了一个单一的，超过700个分支的链 NM长度。该分子与层粘连蛋白和IV型蛋白共同纯化 正常情况下的胶原蛋白。目前的努力旨在 设计制备性提纯技术，使 提纯足以启动发电的数量 克隆抗体和生物功能研究。

In the course of studying extracellular matrix synthesis by various childhood tumors, we have encountered a previously unidentified, high molecular weight (500,000 D) protein secreted into the conditioned medium of several tumor cell lines. This protein is secreted in connection with laminin, type IV collagen, and fibronectin, but is immunologically distinct therefrom. It is also nonreactive with antibodies to basal lamina proteoglycan. It fails to label with radiolabelled sodium sulfate or glycosyl precursors, which further distinguishes it from conventional proteoglycans. Selective enzymatic degradation studies indicate that the protein is trypsin and pepsin sensitive, but collagenase and GAG degrading enzyme insensitive. Ultrastructural studies of rotary shadowed, purified molecules reveal a single, unbranched chain of over 700 nm length. The molecule co-purifies with laminin and type IV collagen under normal circumstances. Current efforts are aimed at devising preparative purification techniques which will allow purification of quantities sufficient to initiate the generation of monoclonal antibodies and biologic function studies.