“鸡皮糙”山药过氧化物酶的酶学特性

Study on the Enzymatic Characteristics of POD from Jipicao Yam

对"鸡皮糙"山药中过氧化物酶(POD)酶学特性进行了较为系统的研究。结果表明,"鸡皮糙"山药过氧化物酶的最适pH为4.0,最适温度为35℃,在60℃以下有良好的稳定性;该酶与不同底物结合能力的强弱依次为:绿原酸>愈创木酚>焦性没食子酸>邻苯二酚>没食子酸;Ca2+、Fe2+、Ba2+、Mg2+对该酶有激活作用,K+、Mn2+、Na+对该酶有抑制作用;抗坏血酸、L-半胱氨酸、植酸、草酸、柠檬酸、EDTA-2Na、NaHSO3等褐变抑制剂对酶活力均有不同程度的抑制作用,其中抗坏血酸和L-半胱氨酸抑制效果最好。

A systematic research on the characteristics of POD from Jipicao Yam was carried out. The results indicated that the optimal pH for this enzyme was 4.0 and POD had its greatest activity at temperature 35 ℃. POD was stable relatively when temperature was below 60℃. The capability of the POD combining with various substrates was in the following order from high to low： Chlorgenic acid, Guaiacol, Pyrogallic acid, Catechol, and Gallic acid. Ca2＋ , Fe2＋ ,Ba2＋ and Mg2 ＋ improved the activity. K ＋ , Mn2 ＋ and Na ＋ could inhibit the activity. Vc, L-cysteine, Phytic acid, Oxalic acid, Citric acid, EDTA-2Na and NaHSO3 had different inhibiting effects on the activity of POD, wherein Vc and L-cysteine were the most effective inhibitors.