Exotic collagen gradients in the byssus of the mussel Mytilus edulis.
Exotic collagen gradients in the byssus of the mussel Mytilus edulis.
复制标题
贻贝足丝中的外来胶原蛋白梯度。
DOI：
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发表时间：
1995
影响因子：
2.8
通讯作者：
J. Waite
中科院分区：
文献类型：
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作者：
Xiaoxia Qin;J. Waite
紫贻贝（Mytilus edulis）的深海丝含有胶原分子，从其中分离出两个抗胃蛋白酶片段并进行了表征。这些显示出沿着线的长度沿着互补分布，使得一个在远端（Col-D）占优势，另一个在近端（Col-P）占优势。两个片段均含有三个相同的α-样链，分子量为50 kDa（Col-P）和60 kDa（Col-D），并具有典型的胶原氨基酸组成;例如，35%甘氨酸和几乎20%脯氨酸加4-反式-羟脯氨酸。不存在羟赖氨酸和3-羟脯氨酸。Col-P序列也是胶原蛋白的典型序列，由三联体Gly-X-Y的串联重复组成，其中X和Y通常代表任何氨基酸。当脯氨酸出现时，它仅在Y位置被羟基化为4-反式-羟基脯氨酸。七个实例，其中X是甘氨酸已被检测到Col-P。特定的多克隆抗Col抗体被用来分离前体的Col-P和Col-D的贻贝脚。PreCol-P的分子量为95 kDa，含有36%的甘氨酸，但亚氨基酸含量较低（13%）。它与另一种前体（preCol-D，97 kDa）沿足的长度沿着具有互补分布。这两种前体组合物分别在preCol-P和preCol-D的非胶原结构域中提示节枝弹性蛋白样和丝素蛋白样结构。免疫金标记研究表明，Col-P与螺纹近端部分内芯的盘绕纤维相关，而Col-D则定位于远端螺纹的直纤维束以及近端螺纹的外芯。
Byssal threads of the common mussel Mytilus edulis contain collagenous molecules from which two pepsin-resistant fragments have been isolated and characterized. These show a complementary distribution along the length of the thread, such that one predominates distally (Col-D) and the other proximally (Col-P). Both fragments contain three identical alpha-like chains with molecular masses of 50 kDa (Col-P) and 60 kDa (Col-D) and have typically collagenous amino acid compositions; for example, 35% glycine and almost 20% proline plus 4-trans-hydroxyproline. Hydroxylysine and 3-hydroxyproline were absent. Col-P sequences are also typical of collagen in consisting of tandem repeats of the triplet Gly-X-Y in which X and Y generally represent any amino acid. When proline occurs, it is hydroxylated to 4-trans-hydroxyproline only in the Y position. Seven instances where X is glycine have been detected in Col-P. Specific polyclonal anti-Col antibodies were used to isolate the precursors of Col-P and Col-D from the mussel foot. PreCol-P has a molecular mass of 95 kDa and contains 36% glycine but a lower imino acid content (13%). It has a complementary distribution with another precursor (preCol-D, 97 kDa) along the length of the foot. The two precursor compositions suggest resilin-like and silk-fibroin-like structures, respectively, in the noncollagenous domains of preCol-P and preCol-D. Immunogold labelling studies indicate that Col-P is associated with the coiled fibers of the inner core in the proximal portion of the thread, whereas Col-D is localized to the straight fiber bundles of the distal thread as well as to the outer core of the proximal thread.