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α 醇溶蛋白是人们生活中消费最多的蛋白，由于含有引起乳糜泻（CD）的主要毒性肽成分，也是引起CD的最活跃的蛋白。为了解一粒小麦在小麦品质育种中的潜力，利用1对α 醇溶蛋白的特异引物，采用基因组PCR法从栽培一粒小麦中克隆α 醇溶蛋白新基因，共获得片段大小为856～882 bp的4个基因序列，分别命名为AA 6、AA 8、AA 9和AA 21(GenBank登录号为JN831382～JN831385）。其中，AA 8、AA 9和AA 21均在102位因C→T替换而导致TAG终止子出现成为假基因；AA 6由882个核苷酸构成，可编码293个氨基酸，与已知基因的最高同源性为99%，推断氨基酸序列具有α 醇溶蛋白的典型结构，是α 醇溶蛋白家族的新成员。AA 6的CD毒性肽分析表明，除不含A基因组所没有的glia α和glia α2毒性肽外，其他已知的7种毒性肽均有分布。AA 6和86个来源于小麦及其祖先供体种的α 醇溶蛋白的同源性分析表明，α 醇溶蛋白基因存在基因组来源的差异性，其中，A、D基因组来源的α 醇溶蛋白基因的相似性较高。

英文摘要:

The α gliadins were typically the most consumed storage proteins in human life, however, owing to the main toxic components they contained causing celiac disease (CD), the α gliadins were also the most active proteins in triggering CD. So the objective of this study was to estimate the potential value in wheat quality breeding of the cloned α gliadin sequences from the genomic DNA and to analyze the CD epitopes among them. One new α gliadin gene with full ORF (named as AA 6, GenBank accession No. JN831382) and three pseudogenes (named as AA 8, AA 9, AA 21, GenBank accession No. JN831383, JN831384 and JN831385, respectively) were cloned and sequenced. The three pseudogenes resulted from C to T base transitions, which leading to the alternative of a CAG codon for glutamine into a TAG stop codon at the position of 102 bp.Analysis on the deduced amino acid sequences of AA 6 revealed that AA 6 was characterized with the typical structure of α gliadins,with the highest homology of 99%. Analysis on its CD epitops demonstrated that seven toxic peptides of the nine known epitops were present in AA 6 except for the absence of Glia α2 and Glia α in the A genome. Phylogenetic analysis among AA 6 and 86 genes from common wheat and its ancestral species showed that a clear cluster can be observed according to the origin of their genome. The homology of A genome and D genome was more close than that of B genome.

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