Making Substrates Out of Inhibitors: Distal Cavity Mutations in Dehaloperoxidase from Amphitrite Ornata
نویسندگان
چکیده
منابع مشابه
Proximal cavity, distal histidine, and substrate hydrogen-bonding mutations modulate the activity of Amphitrite ornata dehaloperoxidase.
Dehaloperoxidase (DHP) from Amphitrite ornata is the first globin that has peroxidase activity that approaches that of heme peroxidases. The substrates 2,4,6-tribromophenol (TBP) and 2,4,6-trichlorophenol are oxidatively dehalogenated by DHP to form 2,6-dibromo-1,4-benzoquinone and 2,6-dichloro-1,4-benzoquinone, respectively. There is a well-defined internal substrate-binding site above the hem...
متن کاملPeroxygenase and Oxidase Activities of Dehaloperoxidase-Hemoglobin from Amphitrite ornata
The marine globin dehaloperoxidase-hemoglobin (DHP) from Amphitrite ornata was found to catalyze the H2O2-dependent oxidation of monohaloindoles, a previously unknown class of substrate for DHP. Using 5-Br-indole as a representative substrate, the major monooxygenated products were found to be 5-Br-2-oxindole and 5-Br-3-oxindolenine. Isotope labeling studies confirmed that the oxygen atom incor...
متن کاملEnzyme function of the globin dehaloperoxidase from Amphitrite ornata is activated by substrate binding.
Amphitrite ornata dehaloperoxidase (DHP) is a heme enzyme with a globin structure, which is capable of oxidizing para-halogenated phenols to the corresponding quinones. Cloning, high-level expression, and purification of recombinant DHP are described. Recombinant DHP was assayed by stopped-flow experiments for its ability to oxidatively debrominate 2,4,6-tribromophenol (TBP). The enzymatic acti...
متن کاملResonance Raman study of ferric heme adducts of dehaloperoxidase from Amphitrite ornata.
The study of axial ligation by anionic ligands to ferric heme iron by resonance Raman spectroscopy provides a basis for comparison of the intrinsic electron donor ability of the proximal histidine in horse heart myoglobin (HHMb), dehaloperoxidase (DHP), and horseradish peroxidase (HRP). DHP is a dimeric hemoglobin (Hb) originally isolated from the terebellid polychaete Amphitrite ornata. The mo...
متن کاملKinetic analysis of a naturally occurring bioremediation enzyme: dehaloperoxidase-hemoglobin from Amphitrite ornata.
The temperature dependence of the rate constant for substrate oxidation by the dehaloperoxidase-hemoglobin (DHP) of Amphitrite ornata has been measured from 278 to 308 K. The rate constant is observed to increase over this range by approximately a factor of 2 for each 10 °C temperature increment. An analysis of the initial rates using a phenomenological approach that expresses the peroxidase pi...
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ژورنال
عنوان ژورنال: Biophysical Journal
سال: 2011
ISSN: 0006-3495
DOI: 10.1016/j.bpj.2010.12.1424