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α 醇溶蛋白不仅与小麦面粉的加工品质密切相关，也是诱发乳糜泻（celiac disease，CD）的主要活力蛋白。为了解强筋优质小麦济麦20的α 醇溶蛋白组成及其CD毒性，利用1对α 醇溶蛋白特异引物，采用基因组PCR法，从济麦20中扩增、克隆了27个具有独特编码区的核苷酸序列(命名为：JM20A 1~ JM20A 27，GenBank注册号为：JN831386~JN831392和JX828280~JX828311)。其中，18个核苷酸序列（ JM20A 1~ JM20A 18）具有完整的开放阅读框, 可编码280~313个氨基酸残基组成的α 醇溶蛋白。这18个基因的氨基酸序列除JM20A 1和JM20A 2在特征II区含有1个额外的半胱氨酸外，其他16个均具有α 醇溶蛋白的典型结构特点，含有6个保守的半胱氨酸。对CD免疫肽的分布分析发现，这18个基因的编码蛋白均符合D基因组来源的α 醇溶蛋白的特点，以不同的组合含有2~4种主要的T细胞免疫优势多肽，定位于6D染色体。与来源于栽培一粒小麦（Triticum monococcu）、拟斯脾尔脱山羊草（Aegilops speltoides）和粗山羊草（Aegilops tauschii）的92个α 醇溶蛋白的氨基酸序列的同源性分析表明，这18个基因均与来源于粗山羊的α 醇溶蛋白基因的同源性最高，进一步说明这些基因很可能来源于6D染色体。

英文摘要:

The α gliadins not only play a major role in the gluten quality but also are the most active proteins in triggering celiac disease (CD).In order to reveal the composition of α gliadin genes and have a overview on its CD toxicity, a total of 27 unique clones (designated as JM20A 1~ JM20A 27, GenBank No. JN831386~ JN831392 and JX828280~JX828311), including 18 (designated as JM20A 1~ JM20A 18）novel full ORF of α gliadin genes and 9 pseudogenes, were amplified and cloned from common wheat cultivar Jimai 20 using a PCR based strategy. Comparative analysis on the deduced amino acids showed that the 18 α gliadin genes with full ORF had the typical structures of α gliadin genes reported previously except that 2 genes (JM20A 1, JM20A 2）possessed an additional cysteine residue in the unique domain II. By analysis on the four major immunodominant epitopes, all the 18 novel genes were assigned on chromosome 6D based on the presence of 2~4 major T cell peptides with different combinations. Homological analysis on the deduced amino acid sequences among the 18 novel genes and other 92 genes derived from Triticum monococcum, Aegilops speltoides and Aegilops tauschii showed that all the 18 genes in this work had a relatively high homology with the genes derived from Aegilops tauschi, which further confirmed that the cloned 18 α gliadin genes most likely originated from 6D chromosome.

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