考马斯亮蓝法在茶汤可溶性蛋白含量分析中的应用和改良

Modification of coomassic brilliant blue method and application to protein assay of tea liquor

对考马斯亮蓝 (Coomassie brilliantblue,CBB)染色测定茶汤蛋白含量的方法进行了改良 ,并以牛血清白蛋白 (Bovine serum albumin,BSA)为标准蛋白 ,对影响蛋白分析效果的重要参数进行了研究。结果表明 ,BSA-CBB复合物与茶汤可溶性蛋白 -CBB复合物具有相似的紫外可见吸收图谱 ,分别在 2 0 5 nm、2 60 nm、3 0 5 nm和5 90 nm处出现了 4个吸收峰 ;在茶汤用量 2 .5～ 5 .0 ml、40℃染色 3 0 min、转溶液体用量 1 4.4ml试验条件下 ,可获得良好的分析效果。应用本方法 ,炒青绿茶和红碎茶茶汤 (茶水比为 1 .5 g/ 2 5 0 ml)可溶性蛋白含量分别为 1 9.3 7μg/ ml和 1 8.45 μg/ ml,分析结果的变异系数分别为 0 .5 4%和 1 .0 5 %。

Modifications of Coomassie brilliant blue (CBB) method for proteins assay were made. The key factors affecting the results of tea liquor protein assay were studied, using bovine serum albumin (BSA) as external standard protein. The results showed that BSA-CBB complex and tea liquor proteins-CBB complex had similar ultra-visible (UV) absorption spectrum, and there were 4 peaks occurred at 205nm, 260nm, 305nm and 590nm, respectively, It also showed that the optimum conditions were 2.5~5.0 ml tea liquor, dyeing 30 min at 40℃, and 14.4ml dissolving solution. Protein concentrations in green tea and black tea solutions extracted at water: tea rate of 250ml:1.5g were 19.37μg/ml and 18.45μg/ml, with coefficient of variance of 0.54% and 1.05%, respectively.