VARIANT OF ASCORBATE PEROXIDASE

摘要

PROBLEM TO BE SOLVED: To create an ascorbate peroxidase which does not produce a covalent bond between an apoenzyme and a heme and scarcely cause deactivation by hydrogen peroxide in order to create plants having resistance to various stresses such as high temperature, low temperature and drying.

SOLUTION: The variant of ascorbate peroxidase is characterized by substituting an amino acid residue (amino acid residue to be substituted) facing a heme pocket and existing on Distal side of a heme surface and covalently bonded to a heme by hydrogen peroxide with an amino acid residue (substituting amino acid residue) not covalently bonded to the heme by hydrogen peroxide. For example, it was confirmed that half-life period of enzyme activity by hydrogen peroxide becomes 6.6 times longer by substituting tryptophan positioned at the 35th position of an amino acid sequence of tobacco chloroplast-localized ascorbate peroxide with phenylalanine.

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