白芸豆球蛋白的提取及其氨基酸组成研究

Study on the Extraction and Amino Acid Composition of White Kidney Bean Globulin

本文研究了白芸豆球蛋白的提取工艺、分子量和氨基酸组成。结果表明,白芸豆球蛋白最佳提取工艺为NaCl浓度2.5 g/100 mL,料液比1∶22(g/mL),提取温度55℃,提取时间5 h,在此条件下的球蛋白提取率为31.46%;用60%的硫酸铵,在4℃下盐析1 h,球蛋白的盐析得率为73.55%;球蛋白的SDS-PAGE电泳图谱中有6条蛋白亚基条带,其相对分子质量分别为97.52、47.35、33.84、29.62、26.28和21.99 ku,其中有5条与白芸豆分离蛋白的亚基条带相吻合;球蛋白的氨基酸组成种类齐全,必需氨基酸含量接近FAO/WHO推荐模式,是一种优质植物蛋白质资源。

Extraction technology, molecular weight and amino acid composition of white kidney bean globulin were stud- ied. The result showed that ：the optimized extraction technology of globulin was as foUows ：concentration of NaCI 2.5 g/ 100 mL,solid-liquid ratio 1：22 （g/mL）,extraction temperature 55℃ ,extraction time 5 h,and the extraction yield of globulin was 31.46% under the above conditions. The salting-out rate of globulin was 73.55% ,when globulin was salted out at 4℃ for one hour by 60% ammonium sulphate saturation. Six protein subunit bands were detected in the SDSPAGE electrophoretogram of globulin, their relative molecular weights were 97.52,47.35,33.84,29.62,26.28 and 21. 99 ku, respectively. Five bands were consistent with the subunlt bands of isolated white kidney bean protein. In conclusion, globulin contained abundant amino acids, and the essential amino acid content was close to the FAO/WHO recom- mended pattern. It was a kind of high quality plant protein resource.