LIQUID CRYSTALLINITY IN CONDENSED TYPE-I COLLAGEN SOLUTIONS - A CLUE TO THE PACKING OF COLLAGEN IN EXTRACELLULAR MATRICES
LIQUID CRYSTALLINITY IN CONDENSED TYPE-I COLLAGEN SOLUTIONS - A CLUE TO THE PACKING OF COLLAGEN IN EXTRACELLULAR MATRICES
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DOI：
10.1016/0022-2836(92)90567-4
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发表时间：
1992-04-05
影响因子：
5.6
通讯作者：
GIRAUDGUILLE, MM
中科院分区：
文献类型：
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作者：
GIRAUDGUILLE, MM
我们最近描述了一种新型的胶原蛋白分子组装，在超声处理后的高浓度溶液中形成典型的液晶相。目前的工作表明，完整的300 nm长的胶原蛋白分子也可以形成胆固醇液晶域，但所需的时间要长得多，需要几周而不是几天。差热法和x射线衍射表明超声不改变胶原蛋白片段的三螺旋结构。在粘性溶液中，在光学显微镜下观察到交叉极性之间的织构随浓度的变化而变化。分子首先在盖盖边缘的空气界面附近排列，然后随着溶剂缓慢蒸发浓度的增加，双折射向内延伸，液晶域逐渐出现。当浓度高于100 mg/ml时，可以得到胆甾相的典型结构和缺陷，在较低浓度时，可以观察到锯齿形消光图案和带状图案；所有这些纹理都被描述和解释。胶原原纤维在各种细胞外基质中的胆固醇堆积是已知的，并且可以在体外获得胶原分子的有序相与在体内观察到的纤维蛋白之间的相关几何结构之间建立关系。
We recently described a new type of assembly of collagen molecules, forming typical liquid crystalline phases in highly concentrated solutions after sonication. The present work shows that intact 300 nm long collagen molecules also form cholesteric liquid crystalline domains, but the time required is much longer, several weeks instead of several days. Differential calorimetry and X-ray diffraction show that sonication does not alter the triple-helical structure of the collagen fragments. In the viscous solutions, observed between crossed polars in optical microscopy, the textures vary as a function of the concentration. Molecules first align near the air interface at the coverslip edge, then as the concentration increases by slow evaporation of the solvent, the birefringence extends inwards and liquid crystalline domains progressively appear. For concentrations estimated to be above 100 mg/ml, typical textures and defects of cholesteric phases are obtained, at lower concentrations zig-zag extinction patterns and banded patterns are observed; all these textures are described and interpreted. The cholesteric packing of collagen fibrils in various extracellular matrices is known, and the relationship that can be made between the ordered phases obtained with collagen moleculesin vitroand the related geometrical structures observed between fibrilsin vivois thoroughly discussed.