Characterization of serum immunoglobulin M of grouper and cDNA cloning of its heavy chain
Characterization of serum immunoglobulin M of grouper and cDNA cloning of its heavy chain
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DOI：
10.1016/j.vetimm.2005.08.029
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发表时间：
2006-02-15
影响因子：
1.8
通讯作者：
Chang, CY
中科院分区：
文献类型：
--
作者：
Cheng, CA;John, JAC;Chang, CY
用Protein A-Sepharose柱亲和层析纯化斜带石斑鱼全血清中的免疫球蛋白M(IgM)。还原条件下的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(SDS-PAGE)显示，等摩尔重链和轻链的相对分子质量分别为78,000和27,000。用抗体筛选的方法从石斑鱼肾脏cDNA文库中克隆了编码IgM重链的可变区(V-H区)和恒定区(C-H区)的cDNAs。共鉴定出5个V-H(130-142个氨基酸)和4个C-H(450-454个氨基酸)家族。可变区和恒定区与其推定的结构域是保守的。所有四个恒定区(C-H1-C(H)2-C(H)3-C(H)4)都含有三个保守的半胱氨酸残基，它们被认为形成了链内和链间的二硫键。恒定区有3个碳水化合物受体位点。总体而言，IgM基因的组织模式似乎与其他硬骨鱼相似。此外，石斑鱼IgM中的C-H基因与已报道的大西洋鲑鱼和鲤鱼中的C-H基因一样，是一个多家族。(C)2005 Elsevier B.V.保留所有权利。
Immunoglobulin M (IgM) from the whole serum of grouper fish, Epinephelus coioides was purified by affinity chromatography using protein A-Sepharose column. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions revealed that the relative molecular masses (M,) of the equimolar heavy and light chains of IgM were 78,000 and 27,000, respectively. The cDNAs encoding IgM heavy chain comprising its variable (V-H) and constant (C-H) regions have been cloned and sequenced from a grouper kidney cDNA library by antibody screening method. Five V-H (130-142 amino acids) and four C-H (450-454 amino acids) families were identified. The variable and constant regions were conserved with their putative domains. All the four constant region domains (C-H 1-C(H)2-C(H)3-C(H)4) contained each three conserved cysteine residues, which are considered to form the inter- and intra-chain disulfide bridges. There were three carbohydrate acceptor sites in the constant region. In general, the pattern of IgM gene organization seems to resemble that of other teleosts. Moreover, the C-H genes in grouper IgM occur as multifamily as reported in Atlantic salmon and common carp. (C) 2005 Elsevier B.V. All rights reserved.