The α1(VIII) and α2(VIII) chains of type VIII collagen can form stable homotrimeric molecules
The α1(VIII) and α2(VIII) chains of type VIII collagen can form stable homotrimeric molecules
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DOI：
10.1074/jbc.273.34.22091
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发表时间：
1998-08-21
影响因子：
4.8
通讯作者：
Shuttleworth, A
中科院分区：
文献类型：
--
作者：
Illidge, C;Kielty, C;Shuttleworth, A
VIII型胶原是一种短链胶原。已经描述了两条链，α 1（VIII）和α 2(VIII)，但VIII型胶原的链组成还远远没有解决。为了解决这个问题，我们在一个半透化细胞的体外翻译系统中表达了全长α 1（VIII）和α 2（VIII）链。两条链的翻译产物约为80 kDa，可产生约60 kDa的凝乳胰蛋白酶/胰蛋白酶抗性产物，表明两条链均可形成同型三聚体。脯氨酸残基的羟基化是稳定三聚体形成的先决条件。α 1（VIII）同型三聚体的熔化温度为45℃，而α 2（VIII）的熔化温度为42℃。8型胶原的两条链都能形成稳定的三螺旋，这表明这种胶原可能有不同的形式，细胞可能会根据不同的生物条件调节链的组成。
Type VIII collagen is a short chain collagen. Two chains have been described, alpha 1(VIII) and alpha 2(VIII), but the chain composition of type VIII collagen is far from resolved. To address this question, we have expressed full-length alpha 1(VIII) and alpha 2(VIII) chains in an in vitro translation system supplemented with semipermeabilized cells. Both chains gave a translation product of similar to 80 kDa that could be shown to produce a chymotrypsin/trypsin-resistant product of similar to 60 kDa, indicating that both chains could form homotrimers. Hydroxylation of proline residues was a prerequisite for stable trimer formation. The melting temperature for the alpha 1(VIII) homotrimer was 45 degrees C, whereas that for alpha 2(VIII) was 42 degrees C. The ability of both chains of type VIII collagen to form stable triple helices suggests that there may be different forms of this collagen and that cells may modulate the chain composition in response to different biological conditions.