Charonis A S, Tsilibary E C, Yurchenco P D, Furthmayr H
J Cell Biol. 1985 Jun;100(6):1848-53. doi: 10.1083/jcb.100.6.1848.
A mixture of laminin and type IV collagen was analyzed by rotary shadowing using carbon/platinum and electron microscopy. Laminin was found to form distinct complexes with type IV collagen: one site of interaction is located 140 nm from the COOH-terminal, noncollagenous (NC1) domain and the other is located within the NH2-terminal region. The isolated NC1 fragment of type IV collagen does not appear to interact with laminin, while pepsin-treated type IV collagen, which lacks the NC1 domain, retains its ability to form complexes with laminin. Analysis of the laminin-type IV complexes indicates that laminin binds to type IV collagen via the globular regions of either of its four arms. This finding is supported by experiments using fragment P1 of laminin which lacks the globular regions and which does not bind to type IV collagen in a specific way. In addition, after heat-denaturation of laminin no specific binding is observed.
使用碳/铂旋转阴影法和电子显微镜对层粘连蛋白和IV型胶原蛋白的混合物进行了分析。发现层粘连蛋白与IV型胶原蛋白形成了不同的复合物：一个相互作用位点位于距COOH末端非胶原蛋白（NC1）结构域140nm处，另一个位于NH2末端区域内。IV型胶原蛋白的分离NC1片段似乎不与层粘连蛋白相互作用，而缺乏NC1结构域的经胃蛋白酶处理的IV型胶原蛋白保留了其与层粘连蛋白形成复合物的能力。对层粘连蛋白-IV型复合物的分析表明，层粘连蛋白通过其四条臂中任何一条的球状区域与IV型胶原蛋白结合。使用缺乏球状区域且不以特定方式与IV型胶原蛋白结合的层粘连蛋白片段P1进行的实验支持了这一发现。此外，层粘连蛋白热变性后未观察到特异性结合。
