Isolation and sequence of the vitamin K-dependent matrix Gla protein from the calcified cartilage of the soupfin shark.
Isolation and sequence of the vitamin K-dependent matrix Gla protein from the calcified cartilage of the soupfin shark.
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从汤鳍鲨钙化软骨中分离维生素 K 依赖性基质 Gla 蛋白并进行测序。
DOI：
10.1002/jbmr.5650090417
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Price,PA
中科院分区：
文献类型：
--
作者：
Rice,JS;Williamson,MK;Price,PA
在牛的钙化肋软骨和汤鳍鲨 (Galeorhinus galeus) 的钙化椎软骨中发现了高水平的维生素 K 依赖性基质 Gla 蛋白 (MGP)。在这两个物种中，MGP 占钙化软骨酸脱矿提取物总蛋白质的 35-40%，钙化软骨的矿物质含量与牛皮质骨相当。鲨鱼和牛的 MGP 几乎不溶于中性缓冲液，这是一种保守的特性，表明自聚集对于 MGP 的未知功能可能很重要。确定了鲨鱼 MGP 的完整氨基酸序列，以将软骨鱼类蛋白的结构与目前已知的几种哺乳动物 MGP 序列进行比较。鲨鱼 MGP 在其 102 个残基序列中含有 4 个维生素 K 依赖性氨基酸 γ-羧基谷氨酸残基，计算得出的分子量 = 12,770 道尔顿。鲨鱼MGP的前76个残基与哺乳动物MGP在序列上同源，序列同一性为37%，但鲨鱼蛋白的C端23个残基在哺乳动物MGP中没有对应物。鲨鱼 MGP 的 C 端片段包含 8 个碱性残基，不含酸性残基。鲨鱼 MGP、所有哺乳动物 MGP 以及所有其他目前已知的维生素 K 依赖性哺乳动物蛋白中保守的特征之一是序列同源性的 15 个残基区域，该区域已被证明充当 γ-羧化酶识别序列和未知功能的不变序列 Gla-Xaa-Xaa-Xaa-Gla-Xaa-Cys。
High levels of the vitamin K‐dependent matrix Gla protein (MGP) have been found in the calcified costal cartilage of the cow and the calcified vertebral cartilage of the soupfin shark (Galeorhinus galeus). In both species, MGP accounts for 35–40% of the total protein in the acid demineralization extract of calcified cartilage, and the mineral content of calcified cartilage is comparable to that of bovine cortical bone. Shark and bovine MGP are both nearly insoluble in neutral buffers, a conserved property that indicates that self‐aggregation could be important to the as yet unknown function of MGP. The complete amino acid sequence of shark MGP was determined to compare the structure of the elasmobranch protein to the several currently known mammalian MGP sequences. Shark MGP contains 4 residues of the vitamin K‐dependent amino acid γ‐carboxyglutamic acid in its 102 residue sequence and has a calculated molecular weight = 12,770 daltons. The first 76 residues of shark MGP are homologous in sequence to mammalian MGPs, with 37% sequence identity, but the C‐terminal 23 residues of the shark protein have no counterpart in the mammalian MGPs. This C‐terminal segment of shark MGP contains 8 basic residues and no acidic residues. Among the features conserved in shark MGP, in all mammalian MGPs, and in all other currently known vitamin K‐dependent mammalian proteins are a 15‐residue region of sequence homology that has been shown to function as the γ‐carboxylase recognition sequence and an invariant sequence of unknown function, Gla‐Xaa‐Xaa‐Xaa‐Gla‐Xaa‐Cys.