文献类型： 外文期刊

作者： Wang, Jin-Mei ¹ ; Yang, Xiao-Quan ¹ ; Yin, Shou-Wei ¹ ; Yuan, De-Bao ² ; Xia, Ning ¹ ; Qi, Jun-Ru ¹ ;

作者机构： 1.S China Univ Technol, Dept Food Sci & Technol, Guangzhou 510640, Guangdong, Peoples R China

2.Chinese Acad Trop Agr Sci, Inst Banana & Plantain, Haikou 570102, Peoples R China

3.Guangxi Univ, Sch Light Ind & Food Engn, Nanning 530004, Peoples R China

关键词： beta-conglycinin;individual subunits;polypeptide hydrolysis;conformational changes;assembly;amyloid fibril

期刊名称：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY （ 影响因子：5.279； 五年影响因子：5.269 ）

ISSN： 0021-8561

年卷期： 2011 年 59 卷 20 期

页码：

收录情况： SCI

摘要： The amyloid-like fibrillation of soy beta-conglycinin subunits (alpha, alpha', and beta) upon heating (0-20 h) at 85 degrees C and pH 2.0 was characterized using dynamic light scattering, circular didiroism (CD), binding to amyloid dyes (Thioflavin T and Congo red), and atomic force microscopy. The fibrillation of all three subunits was accompanied by progressive polypeptide hydrolysis. The hydrolysis behaviors, fibrillation kinetics, and morphologies of amyloid-like fibrils considerably varied among alpha, alpha', and beta subunits. Faster hydrolysis rates and special fragments were observed for the alpha and alpha' subunits compared to the beta subunit. However, the order of the fibrillation rate and capacity to form beta-sheets was alpha' > beta > alpha, as evidenced by CD and Thioflavin T data. Moreover, sequential growth of twisted screw-structure fibrils, leading to macroscopic fibrils with distinct morphological characteristics, was observed for beta-conglycinin and individual subunits. The different fibrillation kinetics and morphologies of alpha, alpha', and beta subunits appear to be associated with the differences in the amino acid composition and typical sequence of peptides. Besides, the disruption of ordered structure of fibrils occurred upon further heating (6-20 h) due to extensive hydrolysis. These results would suggest that all subunits are involved in the fibrillation of beta-conglycinin, following multiple steps including polypeptide hydrolysis, assembly to amyloid structure, and growth into macroscopic fibrils with a fibril shaving process.