Axial structure of the heterotypic collagen fibrils of vitreous humour and cartilage
Axial structure of the heterotypic collagen fibrils of vitreous humour and cartilage
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DOI：
10.1006/jmbi.2000.4429
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发表时间：
2001-03-09
影响因子：
5.6
通讯作者：
Bishop, PN
中科院分区：
文献类型：
--
作者：
Bos, KJ;Holmes, DF;Bishop, PN
我们将阴性染色的异型II型胶原原纤维的轴向结构与计算机生成的染色模式进行了比较。理论上的阴性染色模式是基于初级序列中单个氨基酸侧链的“体积”和三螺旋的d -交错排列而创建的。将II型胶原蛋白的理论染色模式与重建的II型胶原原纤维以及从成人和胎儿软骨和玻璃体中分离的原纤维的实验染色模式进行比较并相互关联。分离的原纤维在直径和组成上都有明显的不同。当应用一定程度的理论羟基赖氨酸糖基化时，相关性显着改善，这是第一次表明这种糖基化影响胶原原纤维的阴性染色模式。当V/XI型和IX型胶原蛋白的贡献包括在模拟模型中时，获得了增加的相关性。V/XI型胶原蛋白的n-前肽和TX型胶原蛋白的NC2结构域都在间隙区形成了明显的不染峰。随着原纤维直径的减小，这两个峰均有所增加。用II型、V/XI型和IX型胶原比例组成的理论模式模拟原纤维衍生的染色模式，证实了最薄的原纤维（即玻璃体幽默胶原原纤维）具有最高的次要胶原含量。染色模式的比较表明，胶原蛋白分子在玻璃体和软骨原纤维的组织是相同的。然而，玻璃体幽默的模拟模型并没有考虑到在染色模式中观察到的所有不含染色的肿块；这种额外的质量可能是由胶原蛋白相关的大分子造成的。(C) 2001学术出版社。
We have compared the axial structures of negatively stained heterotypic, type II collagen-containing fibrils with computer-generated staining patterns. Theoretical negative-staining patterns were created based upon the "bulkiness" of the individual amino acid side-chains in the primary sequence and the D-staggered arrangement of the triple-helices. The theoretical staining pattern of type II collagen was compared and cross-correlated with the experimental staining pattern of both reconstituted type II collagen fibrils, and fibrils isolated from adult and foetal cartilage and vitreous humour. The isolated fibrils differ markedly in both diameter and composition. Correlations were significantly improved when a degree of theoretical hydroxylysine glycosylation was applied, showing for the first time that this type of glycosylation influences the negative-staining pattern of collagen fibrils. Increased correlations were obtained when contributions from types V/XI and IX collagen were included in the simulation model. The N-propeptide of collagen type V/XI and the NC2 domain of type TX collagen both contribute to prominent stain-excluding peaks in the gap region. With decreasing fibril diameter, an increase of these two peaks was observed. Simulations of the fibril-derived staining patterns with theoretical patterns composed of proportions of types II, V/XI and IX collagen confirmed that the thinnest fibrils (i.e. vitreous humour collagen fibrils) have the highest minor collagen content. Comparison of the staining patterns showed that the organisation of collagen molecules within vitreous humour and cartilage fibrils is identical. The simulation model for vitreous humour, however, did not account for all stain-excluding mass observed in the staining pattern; this additional mass may be accounted for by collagen-associated macromolecules. (C) 2001 Academic Press.