Structure-quality relationships at molecular level of soybean major storage proteins

大豆主要贮藏蛋白分子水平的结构-质量关系

• 批准号: 12460058
• 负责人: UTSUMI Shigeru
• 金额: $ 7.36万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12460058/
• 关键词: soybean proteins; glycinin; conglycinin; physicochemical function; X-ray crystallography; bile acid-binding ability; 肝汁酸結合能; 乳化性; アレルゲン性

Soybean proteins have cholesterol-lowering ability as well as physicochemical functions. Moreover, their nutritional value is superior among those of plant proteins. Therefore, it is desired to enlarge the usage of soybean proteins. For this, we have to elucidate the structure-quality (physicochemical and physiological functions) relationships at molecular level of soybean proteins. We approached to the elucidation of them as follows.(1) X-ray crystallography of the constituent subunits of glycinin and conglycininThe three dimensional structure of conglycinin α'core was solved at 2.3Å resolution. Bases for crystallography of proglycinin A2B1a and conglycinin αcore were established.(2) Structure-physicochemical function relationships at subunit level of glycinin and conglycininMolecular species composed of a single subunit and restricted subunits were purified from mutant soybean cultivars containing such species. Analyses of their structural features and physiological functions demonstrated that they exhibit the characteristic structure-physicochemical function relationships.(3) Identification of peptide regions contributing bile acid-binding ability of glycininWe identified the most important region responsible for bile acid binding ability of glycinin A1aB1b by using E. coli expression system.(4) Structure-quality relationships at molecular level of glycinin and conglycininWe could understand deeply structure-quality relationships at molecular level of glycinin and conglycinin by protein engineering based on the results obtained by the investigations (1), (2) and (3).

大豆蛋白具有降胆固醇的功能和理化功能。此外，它们的营养价值在植物蛋白中是上级的。因此，希望扩大大豆蛋白的使用。为此，我们必须从分子水平上阐明大豆蛋白质的结构-品质（理化和生理功能）关系。我们对它们的解释如下。(1)大豆球蛋白和伴大豆球蛋白组成亚基的X射线晶体学在2.3 nm分辨率下，解析了伴大豆球蛋白的β '核的三维结构。为前大豆球蛋白A2 B1 a和伴大豆球蛋白α核心的晶体学研究奠定了基础。(2)大豆球蛋白和伴大豆球蛋白亚基水平的结构-理化功能关系从含有单一亚基和限制性亚基的突变大豆品种中分离纯化了由单一亚基和限制性亚基组成的分子物种。通过对它们的结构特征和生理功能的分析，表明它们具有独特的结构-理化功能关系。(3)大豆球蛋白与胆汁酸结合的肽段的鉴定我们利用E. coli表达系统。(4)大豆球蛋白和伴大豆球蛋白分子水平上的结构-质量关系基于（1）、（2）和（3）的研究结果，我们可以通过蛋白质工程深入理解大豆球蛋白和伴大豆球蛋白分子水平上的结构-质量关系。