PLEOMORPHISM IN TYPE-I COLLAGEN FIBRILS PRODUCED BY PERSISTENCE OF THE PROCOLLAGEN N-PROPEPTIDE
PLEOMORPHISM IN TYPE-I COLLAGEN FIBRILS PRODUCED BY PERSISTENCE OF THE PROCOLLAGEN N-PROPEPTIDE
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DOI：
10.1016/0022-2836(89)90335-5
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发表时间：
1989-11-20
影响因子：
5.6
通讯作者：
PROCKOP, DJ
中科院分区：
文献类型：
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作者：
HULMES, DJS;KADLER, KE;PROCKOP, DJ
使用一种从I型胶原和I型PN-胶原的直接生物合成前体酶促合成这些分子的系统，在体外研究了I型胶原和I型PN-胶原的组装。C-蛋白酶消化PC-胶原生成的胶原形成D-周期性条带状的纤维，基本上呈圆柱形(即横截面为圆形)。相反，C-蛋白酶消化前胶原产生的PN-胶原形成了薄片状结构，纵向呈D-周期，横向宽度不同(最大可达几微米)，厚度均匀(约8 nm)。胶原蛋白和PN-胶原蛋白的混合物聚集在一起，形成各种多形性的纤维。随着PN-胶原蛋白含量的增加，原纤维横截面逐渐由圆形向分叶状逐渐变形，向细小的分枝状结构转变。这些结构中的一些类似于在某些遗传性结缔组织疾病中观察到的纤维，其中N-末端前胶原处理有缺陷。根据N-前肽优先位于不断增长的集合体表面的假设来考虑观察结果。讨论了在体内控制胶原纤维正常直径的意义。
The assembly of type I collagen and type I pN-collagen was studied in vitro using a system for generating these molecules enzymatically from their immediate biosynthetic precursors. Collagen generated by C-proteinase digestion of pC-collagen formed D-periodically banded fibrils that were essentially cylindrical (i.e. circular in cross-section). In contrast, pN-collagen generated by C-proteinase digestion of procollagen formed thin, sheet-like structures that were axially D-periodic in longitudinal section, of varying lateral widths (up to several .mu.m) and uniform in thickness (approximately 8 nm). Mixtures of collagen and pN-collagen assembled to form a varied of pleomorphic fibrils. With increasing pN-collagen content, fibril cross-sections were progressively distorted from circular to lobulated to thin and branched structures. Some of these structures were similar to fibrils observed in certain heritable disorders of connective tissue where N-terminal procollagen processing is defective. The observations are considered in terms of the hypothesis that the N-propeptides are preferentially located on the surface of a growing assembly. The implications of normal diameter control of collagen fibrils in vivo are discussed.