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Modification of halogen specificity of a vanadium‐dependent bromoperoxidase
Author(s) -
Ohshiro Takashi,
Littlechild Jennifer,
GarciaRodriguez Esther,
Isupov Michail N.,
Iida Yasuaki,
Kobayashi Takushi,
Izumi Yoshikazu
Publication year - 2004
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.03496004
Subject(s) - vanadium , vanadate , enzyme , chemistry , mutant , halogen , amino acid , residue (chemistry) , active site , biochemistry , enzyme assay , stereochemistry , halide , catalysis , inorganic chemistry , organic chemistry , alkyl , gene
The halide specificity of vanadium‐dependent bromoperoxidase (BPO) from the marine algae, Corallina pilulifera , has been changed by a single amino acid substitution. The residue R397 has been substituted by the other 19 amino acids. The mutant enzymes R397W and R397F showed significant chloroperoxidase (CPO) activity as well as BPO activity. These mutant enzymes were purified and their properties were investigated. The maximal velocities of CPO activities of the R397W and R397F enzymes were 31.2 and 39.2 units/mg, and the K m values for Cl − were 780 mM and 670 mM, respectively. Unlike the native enzyme, both mutant enzymes were inhibited by NaN 3 . In the case of the R397W enzyme, the incorporation rate of vanadate into the active site was low, compared with the R397F and the wild‐type enzyme. These results supported the existence of a specific halogen binding site within the catalytic cleft of vanadium haloperoxidases.