Distinct maturations of N-propeptide domains in fibrillar procollagen molecules involved in the formation of heterotypic fibrils in adult sea urchin collagenous tissues
Distinct maturations of N-propeptide domains in fibrillar procollagen molecules involved in the formation of heterotypic fibrils in adult sea urchin collagenous tissues
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DOI：
10.1074/jbc.m311803200
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发表时间：
2004-03-12
影响因子：
4.8
通讯作者：
Exposito, JY
中科院分区：
文献类型：
--
作者：
Cluzel, C;Lethias, C;Exposito, JY
我们的特点是一个新的海胆纤维胶原蛋白，5 α链，包括9个重复的海胆纤维模块在其N-前肽的一级结构。通过蛋白质印迹和免疫荧光分析，我们已经表明，5 α是共定位于成人胶原韧带与2 α纤维胶原蛋白链和纤维表面蛋白，其他两个细胞外基质蛋白具有海胆纤维模块。在超微结构水平上，5 α N-前肽被检测到在原纤维的表面，这表明在成熟的胶原蛋白分子中保留了这个域。从试验组织（内骨骼）中提取的胃蛋白酶化胶原分子的生物化学表征以及基质辅助激光解吸电离飞行时间分析使我们能够确定与1 α和2 α链相比，5 α是定量上较小的纤维状胶原链。此外，5 α与两个1 α链形成异源三聚体分子。因此，在脊椎动物中，海胆胶原原纤维是由数量上的主要和次要的纤维分子经历不同的成熟，其N-前肽区，并参与异型原纤维的形成。
We have characterized the primary structure of a new sea urchin fibrillar collagen, the 5alpha chain, including nine repeats of the sea urchin fibrillar module in its N-propeptide. By Western blot and immunofluorescence analyses, we have shown that 5alpha is co-localized in adult collagenous ligaments with the 2alpha fibrillar collagen chain and fibrosurfin, two other extracellular matrix proteins possessing sea urchin fibrillar modules. At the ultrastructural level, the 5alpha N-propeptide is detected at the surface of fibrils, suggesting the retention of this domain in mature collagen molecules. Biochemical characterization of pepsinized collagen molecules extracted from the test tissue ( the endoskeleton) together with a matrix-assisted laser desorption ionization time-of-flight analysis allowed us to determine that 5alpha is a quantitatively minor fibrillar collagen chain in comparison with the 1alpha and 2alpha chains. Moreover, 5alpha forms heterotrimeric molecules with two 1alpha chains. Hence, as in vertebrates, sea urchin collagen fibrils are made up of quantitatively major and minor fibrillar molecules undergoing distinct maturation of their N-propeptide regions and participating in the formation of heterotypic fibrils.