Two type XII-like collagens localize to the surface of banded collagen fibrils.
Two type XII-like collagens localize to the surface of banded collagen fibrils.
复制标题
两种类型的XII样胶原蛋白定位于带状胶原纤维的表面。
DOI：
10.1083/jcb.113.4.971
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发表时间：
1991-05
影响因子：
7.8
通讯作者：
Burgeson, R E
中科院分区：
文献类型：
--
作者：
Keene, D R;Lunstrum, G P;Morris, N P;Stoddard, D W;Burgeson, R E
两种最近鉴定的胶原分子，称为十二样A和十二样B（TL-A和TL-B），具有与XII型胶原类似的性质。这些分子已被定位在人类和小牛组织的免疫电镜。观察结果强烈表明，这两种分子位于沿着带状胶原纤维的表面。被抗体识别的表位包含在胶原蛋白螺旋一端的大的非三螺旋结构域中。的表位是可视化的距离约等于长度的非螺旋结构域的带状纤维的表面，这表明非螺旋结构域从原纤维延伸，而三螺旋结构域可能直接结合到原纤维表面。有时，TL-A和TL-B都表现出沿着原纤维表面的周期性分布。该周期对应于带状原纤维的初级带间距离。并非纤维束中的所有原纤维都被标记，标记也不是沿标记的原纤维的长度沿着连续的。TL-A和VI型胶原的同时标记很少显示共定位，表明TL-A和TL- B不介导VI型胶原珠状细丝和带状胶原原纤维之间的相互作用。此外，纤维间的距离在这些XII型样分子的存在和不存在下大致相等。虽然结果并不直接表明这些分子的特定功能，但在原纤维表面的定位表明它们介导原纤维与其他基质大分子或与细胞之间的相互作用。
Two recently identified collagen molecules, termed twelve-like A and twelve-like B (TL-A and TL-B) have properties similar to type XII collagen. These molecules have been localized in human and calf tissues by immunoelectron microscopy. The observations strongly suggest that both molecules are located along the surface of banded collagen fibers. The epitopes recognized by the antibodies are contained in large, nontriple-helical domains at one end of the collagen helix. The epitopes are visualized at a distance from the surface of the banded fibers roughly equal to the length of the nonhelical domains, suggesting that the nonhelical domains extend from the fibril, while the triple-helical domains are likely to bind directly to the fibril surface. Occasionally, both TL-A and TL-B demonstrate periodic distribution along the fibril surface. The period corresponds to the primary interband distance of the banded fibrils. Not all fibrils in a fiber bundle are labeled, nor is the labeling continuous along the length of labeled fibrils. Simultaneous labeling of TL-A and type VI collagen only rarely shows colocalization, suggesting that TL-A and TL- B do not mediate interactions between the type VI collagen beaded filaments and banded collagen fibrils. Also, interfibrillar distances are approximately equivalent in the presence and absence of these type XII-like molecules. While the results do not directly indicate a specific function for these molecules, the localization at the fibril surface suggests that they mediate interactions between the fibrils and other matrix macromolecules or with cells.