A NEW HIGH MOLECULAR WEIGHT EXTRACELLULAR MATRIX PROTEIN

在研究细胞外基质合成的过程中， 儿童肿瘤，我们遇到了一种以前无法确定的，兴奋的 分泌到条件培养液中的分子量(500,000 D)蛋白质 几种肿瘤细胞系。这种蛋白质的分泌与 层粘连蛋白、IV型胶原和纤维连接蛋白，但在免疫学上是不同的 从那以后。它也不与基底膜抗体发生反应。 蛋白多糖。它没有用放射性标记的硫酸钠或 糖基前体，这进一步区分了它与传统的 蛋白多糖。选择性酶降解研究表明， 蛋白质对胰酶和胃酶敏感，但胶原酶和GAG降解 酶不敏感。旋转遮蔽、纯化的超微结构研究 分子显示出一条长度超过700纳米的单一的无支链。这个 正常情况下与层粘连蛋白和IV型胶原的分子共纯化 情况。目前的努力旨在设计准备工作 允许提纯数量的提纯技术 足以启动产生单抗和生物 机能研究。

In the course of studying extracellular matrix synthesis by various childhood tumors, we have encounterd 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 radiolabeled 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.