Raspanti Mario, Viola Manuela, Sonaggere Myriam, Tira Maria Enrica, Tenni Ruggero
Department of Human Morphology, Insubria University, Varese, Italy.
Biomacromolecules. 2007 Jul;8(7):2087-91. doi: 10.1021/bm070091t. Epub 2007 May 27.
Collagen fibrils were obtained in vitro by aggregation from acid-soluble type I collagen at different initial concentrations and with the addition of decorin core or intact decorin. All specimens were observed by scanning electron microscopy and atomic force microscopy. In line with the findings of other authors, lacking decorin, collagen fibrils undergo an extensive lateral association leading to the formation of a continuous three-dimensional network. The addition of intact decorin or decorin core was equally effective in preventing lateral fusion and restoring the normal fibril appearance. In addition, the fibril diameter was clearly dependent on the initial collagen concentration but not on the presence/absence of proteoglycans. An unusual fibril structure was observed as a result of a very low initial collagen concentration, leading to the formation of huge, irregular superfibrils apparently formed by the lateral coalescence of lesser fibrils, and with a distinctive coil-structured surface. Spots of incomplete fibrillogenesis were occasionally found, where all fibrils appeared made of individual, interwined subfibrils, confirming the presence of a hierarchical association mechanism.
通过在不同初始浓度下从酸溶性I型胶原蛋白聚集，并添加核心饰胶蛋白或完整饰胶蛋白，在体外获得了胶原纤维。所有标本均通过扫描电子显微镜和原子力显微镜进行观察。与其他作者的研究结果一致，缺乏饰胶蛋白时，胶原纤维会发生广泛的横向缔合，导致形成连续的三维网络。添加完整的饰胶蛋白或饰胶蛋白核心在防止横向融合和恢复正常纤维外观方面同样有效。此外，纤维直径明显取决于初始胶原蛋白浓度，而不取决于蛋白聚糖的存在与否。由于初始胶原蛋白浓度非常低，观察到一种不寻常的纤维结构，导致形成巨大的、不规则的超级纤维，显然是由较小纤维的横向合并形成的，并且具有独特的螺旋结构表面。偶尔会发现不完全纤维形成的斑点，其中所有纤维似乎都是由单独的、相互缠绕的亚纤维组成，证实了存在分级缔合机制。
