Analysis on the storage protein composition of common buckwheat

荞麦（Fagopyrum esculentum Moench）的主要过敏原Fage 1是其最丰富的贮藏蛋白13S球蛋白的β多肽。由于13S球蛋白是由多种多样的亚基组成的，因此对13S球蛋白的亚基进行了表征。13S球蛋白α多肽可分为4种类型，并进一步分为贫甲硫氨酸亚基和富甲硫氨酸亚基，分别为主要和次要类型。α多肽之间大小的巨大差异可以用串联重复序列的不同长度来解释。除了三个已知的甲硫氨酸贫亚基的13S球蛋白，四个新的甲硫氨酸贫亚基与0，2，4，和6串联重复似乎存在。由于串联重复区是亲水性的，有许多精氨酸残基，对胰蛋白酶的消化率是不同的亚基之间的串联重复和没有。串联重复插入在甲硫氨酸贫亚基的13S球蛋白可能会降低常见的荞麦过敏原。

The prevalent allergen of common buckwheat (Fagopyrum esculentum Moench), Fage 1, is β polypeptide of the most abundant storage protein, 13S globulin. Because the13S globulin is composed of multiple diversified subunits, the subunits of 13S globulinwere characterized. The 13S globulin α polypeptides were categorized into four typesand were further grouped into methionine-poor and methionine-rich subunits as major andminor types, respectively. The large variation in size among the α polypeptides was explained by the different lengths of the tandem repeats. Beside the three known methionine-poor subunits of 13S globulin, four new methionine-poor subunits with 0, 2, 4, and 6 tandem repeats seemed to exist. Because the tandem repeat region was hydrophilic with many arginine residues, digestibilities against trypsin were different between the subunits with and without the tandem repeat. The tandem repeat insertion in the methionine-poor subunits of the 13S globulin may reduce common buckwheat allergenicity.