【摘要】 溴过氧化物酶(BrPOD)是具有特殊功能的过氧化物酶,海藻是其主要来源。对几种中国海域的红藻如角叉菜(Chondrus ocellatus)、龙须菜(Gracilaria sjoestedtii)、珊瑚藻(Corallina officinalis)进行了溴过氧化物酶的藻种筛选,并对酶活较高的珊瑚藻进行溴过氧化物酶分离纯化及性质的研究。通过硫酸铵沉淀、DEAE-cellulose 52离子交换层析、Sephadex G-100凝胶层析等方法,从珊瑚藻中分离得到溴过氧化物酶。对该酶性质研究表明,该酶分子量较大,表观分子量为64 kD;溴化单氯甲酮的最适pH值为6.0;pH在5.0-9.0时酶活性稳定;在30-70℃温度范围内酶活性稳定;Ca2+、Co2+、Cu2+、Mn2+、NaF和EDTA等化合物使溴过氧化物酶活性下降,钒酸盐能提高酶活性。反应动力学实验表明,该酶对Br-、H2O2的Km分别为7.40 mmol/L和96.09μmol/L。更多还原

【Abstract】 Bromoperoxidase was a kind of peroxidase which was found particularly in marine red algae.In this study,bromoperoxidase activity was detected in extracts of three species of marine red marco algae Chondrus ocellatus,Gracilaria sjoestedtii and Corallina officinalis collected in the Yellow Sea.C.officinalis presented the highest specific bromoperoxidase activity among the three species.Bromoperoxidase was purified from the crude extract of C.officinalis by(NH4)2SO4 sedimentation,DEAE-cellulose 52 and Sephadex G-100 chromatography.Characterization of bromoperoxidase from Corallina officinalis was studied.The relative molecular mass was 64 kD as determined by denature gel electrophoresis.The optimal pH for bromoination was 6.0 and bromoperoxidase activity was stable as stored at pH 5.0-9.0.The bromoperoxidase of Corallina officinalis showed remarkable thermostability,retaining appreciable activity at 30-70 ℃.Of a range of compounds,only vanadium enhanced bromoperoxidase.Kinetic studies for the bromination of monochlorodimedone(MCD) gave the Km of Br-and H2O2 as 7.40 mmol/L and 96.09 μmol/L respectively.更多还原