THE NOVEL NONHEME VANADIUM BROMOPEROXIDASE FROM MARINE-ALGAE - PHOSPHATE INACTIVATION

被引:11
作者
SOEDJAK, HS [1 ]
EVERETT, RR [1 ]
BUTLER, A [1 ]
机构
[1] UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106
来源
JOURNAL OF INDUSTRIAL MICROBIOLOGY | 1991年 / 8卷 / 01期
关键词
VANADIUM BROMOPEROXIDASE; PHOSPHATE INACTIVATION; MARINE ALGA; CHLORAMINE; BROMOPEROXIDASE; CHLOROPEROXIDASE;
D O I
10.1007/BF01575589
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
Vanadium bromoperoxidase is a naturally occurring vanadium-containing enzyme isolated from marine algae. V-BrPO catalyzes the oxidation of halides by hydrogen peroxide which can result in the halogenation of organic substrates. Bromoperoxidase activity is measured by the halogenation of monochlorodimedone (2-chloro-5,5-dimethyl-1,3-dimedone, MCD). In the absence of an organic substrate, V-BrPO catalyzes the halide-assisted disproportionation of hydrogen peroxide yielding dioxygen. The dioxygen formed is in singlet excited state (1O2). V-BrPO is quite stable to thermal denaturation and denaturation by certain organic solvents which makes V-BrPO an excellent candidate for industrial applications. The stability of V-BrPO in the presence of strong oxidants and in the presence of phosphate is reported. Incubation of V-BrPO in phosphate buffer (1-100 mM at pH 6; 2-10 mM at pH 5) inactivates the enzyme. The inactivity can be fully restored by the addition of vanadate if excess phosphate is removed. The inactivation of V-BrPO by phosphate can be prevented by the presence of H2O2 (4-40 mM). We are currently investigating the mechanism of V-BrPO inactivation by phosphate. V-BrPO was not inactivated by HOCl (1 mM) nor H2O2. In addition V-BrPO was not inactivated under turnover conditions of 1 mM H2O2 with 0.1-1 M Cl- at pH 5 nor 2 mM H2O2 with 0.1 M Br-.
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页码:37 / 44
页数:8
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