title: Enhancing effect of calcium and vanadium ions on thermal stability of bromoperoxidase from Corallina pilulifera.
abstract: Bromoperoxidase from the macro-alga Corallina pilulifera is an enzyme that possesses vanadate in the catalytic center, and shows a significant thermostability and stability toward organic solvents. The structural analysis of the recombinant enzyme overexpressed in yeast revealed that it contains one calcium atom per subunit. This has been confirmed by inductively coupled plasma emission spectrometry experiments. The study of the effect of metal ions on the apo-enzyme stability has shown that the calcium ion significantly increased the enzyme stability. In addition, vanadate also increased the thermostability and strontium and magnesium ions had similar effects as calcium. The holo-enzyme shows high stability in a range of organic solvents. The effect of the different ions and solvents on the structure of the enzyme has been studied by circular dichroism experiments. The high stability of the enzyme in the presence of organic solvents is useful for its application as a biocatalyst.
authors.affiliation: Henry Wellcome Building for Biocatalysis, School of Biological and Chemical Sciences, University of Exeter, Exeter, EX4 4QD, UK.
authors.forename: Esther
authors.initials: E
authors.lastname: Garcia-Rodriguez
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohshiro
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Aibara
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Izumi
authors.forename: Jennifer
authors.initials: J
authors.lastname: Littlechild
mesh_terms: D000595:Amino Acid Sequence; D001051:Apoenzymes / Q000378:metabolism; D002118:Calcium / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D004795:Enzyme Stability / Q000187:drug effects; D007477:Ions / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008982:Molybdenum / Q000494:pharmacology; D010544:Peroxidases / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D000461:Rhodophyta / Q000201:enzymology*; D016415:Sequence Alignment; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology; D013696:Temperature; D017973:Tungsten Compounds / Q000494:pharmacology; D014639:Vanadium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001051:Apoenzymes; D007477:Ions; D021122:Protein Subunits; D012997:Solvents; D017973:Tungsten Compounds; D014639:Vanadium; C044659:molybdate; D008982:Molybdenum; D010544:Peroxidases; C026195:bromide peroxidase; C045951:tungstate; D002118:Calcium