冬虫夏草蛋白图谱及干燥条件对超氧化物歧化酶活性影响

Protein fingerprint of Chinese cordyceps and the effects of drying condition on the SOD activities

本文采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和双向电泳(2-DE)技术对3个野生冬虫夏草样本和3个培植冬虫夏草样本进行了比较分析。SDS-PAGE结果显示6个样品的蛋白质分子量主要分布在3–66.4k Da之间,Quantity one软件处理凝胶图谱显示蛋白条带在20–23条之间;采用PDQuest软件对双向电泳图谱处理,共检测到670–936个蛋白点,蛋白质主要分布在等电点为p I 4.5–6、分子量为29.0–66.7k Da和14.3–20.1k Da两个区域。尽管在不同样品之间存在一定程度的蛋白质差异,但是并没有发现野生冬虫夏草和培植冬虫夏草之间有显著差异。以超氧化物歧化酶(SOD)活力为评价指标对新鲜冬虫夏草以及冷冻干燥、20℃阴干和60℃烘干冬虫夏草样品进行比较,发现新鲜冬虫夏草SOD活力最高,冷冻干燥对冬虫夏草SOD活力的影响小于20℃阴干干燥,60℃烘干干燥对冬虫夏草SOD活力破坏最大,结果表明干燥条件对冬虫夏草SOD活性极其重要。

The analysis protocols for Chinese cordyceps proteins by sodium dodeccyl sulphate-polyacrylamide gel electrophoresis（SDS-PAGE） and two-dimensional electrophoresis（2-DE） technologies were established and applied for analyzing three wild samples and three cultivated samples of Chinese cordyceps. The results of SDS-PAGE showed that the ranges of protein molecular weight of 6 samples were 3–66.4k Da, and the numbers of protein bands were 20 to 23. The 2-DE profiles resultedfrom PDQuest software showed that 670–936 protein spots were detected and the isoelectric point distributed between p I 4.5 and 6, protein molecular weight distributed between 29.0k Da and 66.7k Da and 14.3k Da and 20.1k Da. Although protein profiles were somewhat different among samples, there were no significant differences between natural and cultivated Chinese cordyceps. The superoxide dismutase（SOD） vitality was detected to compare the fresh, freeze drying, air drying（at 20°C） and oven drying（at 60°C） samples of Chinese cordyceps. As for SOD activity, fresh samples were the highest and the samples treated with lyophilization and air drying at 20°C came second. The lowest SOD activity was obtained from the samples treated by oven drying at 60°C. The results showed that the SOD activity was significantly affected by the drying conditions.