Yurchenco P D, Furthmayr H
Biochemistry. 1984 Apr 10;23(8):1839-50. doi: 10.1021/bi00303a040.
The in vitro self-assembly of murine type IV collagen was examined by using biochemical and morphological techniques. Dimeric collagen undergoes a rapid and reversible thermal gelation at neutral pH without an appreciable lag period. The process is seen to be concentration dependent and inhibited by 2 M urea. The formed complex can be visualized by electron microscopy rotary shadowing as an irregular polygonal lattice network with extensive side by side associations within the collagenous triple-helical part of the molecules, two and three strands thick. Measurements on the matrix suggest a median stagger dimension of 170 nm, one-fifth the length of a dimer. The conversion of pepsin-generated monomers into N-terminally bound tetramers can also be demonstrated in vitro. This process is also concentration dependent and inhibited and reversed by 2 M urea but is thermally irreversible and occurs at a slow rate relative to the lateral associations. These tetramers can be seen by rotary shadowing as four-armed "spider" structures. It is proposed that lateral associations, by virtue of their faster rate of formation, precede 7S bond formation, and several models for the assembly of basement membrane collagen are discussed.
运用生化和形态学技术研究了小鼠IV型胶原的体外自组装过程。二聚体胶原在中性pH条件下经历快速且可逆的热凝胶化，无明显延迟期。该过程呈浓度依赖性，且受2M尿素抑制。通过电子显微镜旋转投影可观察到，形成的复合物为不规则多边形晶格网络，在分子的胶原三螺旋部分内存在广泛的并排缔合，厚度为两到三条链。对基质的测量表明，中位交错尺寸为170nm，是二聚体长度的五分之一。在体外也可证明胃蛋白酶产生的单体转化为N端结合的四聚体。该过程同样呈浓度依赖性，受2M尿素抑制并可逆转，但热不可逆，且相对于横向缔合发生速率较慢。通过旋转投影可将这些四聚体视为四臂“蜘蛛”结构。有人提出，由于横向缔合形成速率更快，其先于7S键形成，并讨论了基底膜胶原组装的几种模型。
