核桃青皮多酚氧化酶的酶学特性  

Enzyme Properties of Polyphenol Oxidase in Green Husks of Walnut(Juglans regia L.)

作　　者：杨卫民[1] 杜京旗[1] 赵君[1] 

机构地区：[1]吕梁学院生命科学系,山西吕梁033001

出　　处：《西部林业科学》2016年第5期12-18,共7页Journal of West China Forestry Science

基　　金：吕梁学院自然科学校内基金(ZRXN201411)

摘　　要：以吕梁本地的"中林1号"核桃青皮为材料,采用比色法对影响核桃青皮多酚氧化酶(PPO)活性的因素,如底物、温度、pH以及激活和抑制作用开展了研究。结果表明,以邻苯二酚为底物,在其浓度0.05mol/L、温度20℃、pH6.0下,波长294nm处核桃青皮PPO活性最高;浓度0.5mol/L的MgCl_2对PPO激活作用最强,酶活力为32.2 U/min;CuSO_4次之,为19.1U/min;乙醇的激活作用也很强,6%乙醇酶活力为27.5U/min;芦丁、Na_2SO_3和L-半胱氨酸(L-Cys)对PPO活性有较强的抑制作用,且随浓度的增加其抑制率越来越明显。By taking the green husk from Walnut Zhonglin 1 as the materials, and based on color-comparison approach, the influence factors of polyphenol oxidase （PPO） activity such as substrate, temperature, pH, and activating and inhibitory were studied. The results showed that catechol as substrate with the concentration of 0. 05mol/L, temperature of 20%, pH of 6. 0, the PPO activity in green husk of walnut was strongest at 294nm. The effect of 0. 5mol/LMgC12 on PPO activation, 32. 2 U/min, was the strongest, and CuSO4 was second with 19.1U/min. The effect of ethanol on enzyme activity was also strong, 27.5 U/min under 6% ethanol. The rutin, Na2SO3 and L-cysteine （L-Cys） have strong inhibition on PPO activity, and its inhibition rate increased as concentration increasing.

关 键 词：核桃青皮 多酚氧化酶 酶促动力 激活剂 抑制剂 

分 类 号：Q946.5[生物学—植物学] TQ28[化学工程—有机化工]