Structural transitions of sword bean canavalin in response to different salt concentrations
Structural transitions of sword bean canavalin in response to different salt concentrations
复制标题
DOI：
10.1016/j.heliyon.2019.e03037
复制
发表时间：
2019-12-01
期刊：
影响因子：
4
通讯作者：
Arii, Yasuhiro
中科院分区：
文献类型：
--
作者：
Nishizawa, Kaho;Arii, Yasuhiro
刀豆蛋白是刀豆（Canavalia gladiata）中的主要贮藏蛋白，属于7S种子球蛋白类。刀豆球蛋白的溶解度可以通过添加不同浓度的MgCl 2和CaCl 2而可逆地改变;具体地说，它在较低浓度下不溶，而在较高浓度下可溶。然而，NaCl的加入并不诱导刀豆球蛋白的不溶解。在这项研究中，它被确定，NaCl的加入导致几乎完全溶解的MgCl 2沉淀的刀豆球蛋白在高浓度的存在下。此外，使用凝胶过滤，我们研究了可溶性刀豆球蛋白在豆类提取物和高浓度盐的存在下的四级结构。结果表明，在蒸馏水粗提物中，刀豆球蛋白以单体形式存在。或者，我们确定了三聚体可溶性刀豆球蛋白在高浓度的NaCl或MgCl 2的存在下。我们的研究表明，刀豆可溶性蛋白质的四级结构不同，在粗提物相比，在高浓度的盐溶液。β-伴大豆球蛋白是大豆中典型的7S-种子球蛋白，其三维结构在高浓度NaCl存在下具有三聚体形式。然而，目前还不清楚β-伴大豆球蛋白是否以三聚体形式存在于大豆种子中。我们的研究结果为分析7S球蛋白特性提供了重要参考。
Canavalin is the major storage protein in sword beans (Canavalia gladiata) and belongs to the 7S seed globulin class. Canavalin solubility can be reversibly altered via the addition of MgCl2 and CaCl2 at different concentrations; specifically, it is insoluble at lower concentrations and soluble at higher concentrations. However, the addition of NaCl does not induce the insolubilization of canavalin. In this study, it was determined that the addition of NaCl causes the nearly complete solubilization of MgCl2-precipitated canavalin in the presence of high concentrations. Moreover, using gel filtration we examined the quaternary structures of soluble canavalin in the bean extract and in the presence of high-concentration salts. Results indicated that canavalin was present in the monomer form within crude extracts with distilled water. Alternatively, we identified trimeric soluble canavalin in the presence of high concentrations of NaCl or MgCl2. Our study revealed that the quaternary structures of sword bean soluble proteins differ in crude extract compared to those in high-concentration salt solutions. The three-dimensional structure of beta-conglycinin, which is a typical 7S-seed globulin in soybean, has a trimer form in the presence of high concentrations of NaCl. However, it remains unclear whether beta-conglycinin is present as trimers in soybean seed. Our findings serve as an important reference to analyze 7S globulin characteristics.