荔枝果肉过氧化物酶酶学性质研究  

Characterization of Peroxidase from Pulp of Litchi

作　　者：刘春丽[1] 

机构地区：[1]四川理工学院生物工程学院,四川自贡643033

出　　处：《西南农业学报》2012年第2期424-428,共5页Southwest China Journal of Agricultural Sciences

摘　　要：本文从荔枝果肉中提取了过氧化物酶(POD),对其酶学性质进行了研究。结果表明,该酶最适反应温度为45℃,对热较敏感,当温度为70℃以上时,短时处理即可使酶活降至50%以下。最适pH 5,但在pH 6.0～8.0范围内活力比较稳定。该酶在25℃和0.1 mol/L磷酸缓冲液(pH7.0)条件下对愈创木酚和没食子酸的Km值分别是4.64×10-3和0.063 mol/L。谷胱甘肽和亚硫酸盐能完全抑制POD活性,但谷胱甘肽抑制浓度远低于亚硫酸盐,抗坏血酸只能在延迟时间内抑制POD活性,对POD抑制具有暂时性,各抑制机制不同;CuSO4、ZnSO4、CaCl2、MgCl2、EDTA对荔枝果肉POD活性有一定激活作用;FeSO4和MnSO4对POD活性有较强的抑制作用。In this paper,the peroxidase（POD） from pulp of litchi（Litchi chinensis Sonn） was extracted and purified.The result showed that the enzyme was relatively sensitive to heat with optimum temperature of 45 ℃,requiring a short time at 70 ℃ for 50 % loss of the activity.Litchi pulp POD had a optimum pH 5,but it was stable within a range of pH 6.0-8.0.the apparent Km values with guaiacol and pyrogallol as substrates were 4.64×10-3 and 0.063 mol/L at 25 ℃,pH 7.0, respectively.The inhibition studies indicated that glutathione were strong inhibitors even at low concentrations while sulfites inhibited moderately,and ascorbic acid inhibited POD temporarily,the inhibition mechanisms of glutathione,sulfites and ascorbic acid were different.CuSO4,ZnSO4,CaCl2,MgCl2, EDTA partially enhanced POD activity,the presence of FeSO4 and MnSO4 inhibitied POD activity.

关 键 词：荔枝果肉 过氧化物酶 酶学特性 

分 类 号：S667.1[农业科学—果树学]