2010 Fiscal Year Final Research Report

Analysis on the storage protein composition of common buckwheat

Research Project

Project/Area Number	20580013
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Crop science/Weed science
Research Institution	Kyoto University
Principal Investigator	TANAKA Tomouyuki (勝部朋之) Kyoto University, 大学院・農学研究科, 准教授 (50224473)
Project Period (FY)	2008 – 2010
Keywords	ソバ / アレルゲン / 貯蔵タンパク質
Research Abstract	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.