NEW HIGH MOLECULAR WEIGHT EXTRACELLULAR MATRIX PROTEIN

在研究细胞外基质合成的过程中 儿童时期的各种肿瘤，我们以前都遇到过 分泌的未知高分子量(500,000 D)蛋白质 进入几个肿瘤细胞系的条件培养液中。这 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。它是 对基底膜蛋白多糖抗体也无反应。它 未能用放射性标记的硫酸钠或糖基标记 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 这种蛋白质对胰酶和胃酶敏感，但胶原酶 GAG降解酶不敏感。超微结构研究 旋转阴影，纯化的分子揭示了一个单一的， 长度超过700纳米的无支链。分子共- 正常情况下用层粘连蛋白和IV型胶原纯化 情况。目前的努力旨在设计出 制备性纯化技术，将允许纯化 具有足够的数量以启动单克隆体的产生 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.