鸡内金淀粉酶理化特性研究

Study on the Physico-chemical Properties of Endothelium Corneum Amylase

目的寻找鸡内金淀粉酶的最佳炮制工艺和理化性质。方法50℃烘干后,用磷酸缓冲液提取鸡内金淀粉酶,分别在不同温度、pH值、不同金属离子处理下测定酶活力,进行聚丙烯酰胺凝胶电泳。结果鸡内金淀粉酶的最适反应pH、最适反应温度和最适底物浓度分别为8.67、50℃和1.8g/mL;实验条件下,以淀粉为底物的Km是0.92;Ca2+、Fe2+、Zn2+、Mn2+等金属离子对淀粉酶活性有抑制作用;聚丙烯酰胺凝胶电泳显示一条谱带,表明鸡内金中可能无淀粉酶同工酶存在。结论鸡内金炮制加工过程中要注意金属离子的影响。

Objectives To search for the optimal processing procedure and physico-chemical properties of Endothelium corneum amylase. Methods After dried under 50 ℃, amylase was extracted from Endothelium comeum with phosphate-buffered saline. The amylase activity was examined at different temperature, pH and different metal ions, and amylase isozyme was discerned on PAGE. Results The optimal pH, optimal temperature, and optimal substrate concentration for amylase activity were 8.67, 50 ℃ and 1.8 g/mL, respectively. Under the experimental conditions, the amylase Km was 0.92 （starch was used as substrate of amylase）. Four metal ions tested, including Ca^2＋, Fe^2＋, Zn^2＋, Mn^2＋, could inhibit the amylase activity to some extent. Furthermore, it showed one amylase isozyme band using PAGE, suggesting only one amylase isozyme existing in the Endothelium comeum tentatively.Conclusion The effects of metal ions should be considered in the process of Endothelium comeum amylase.