Isolation, characterization, and primary structure of the vanadium chloroperoxidase from the fungus Embellisia didymospora.
Here we describe the isolation, purification, and basic kinetic parameters of a vanadium type chloroperoxidase from the hyphomycete fungus Embellisia didymospora. The enzyme proved to possess similar high substrate affinities, a Km of 5 microM for a bromide, 1.2 mM for a chloride, and 60 microM for a hydrogen peroxide, as those of the vanadium chloroperoxidase from Curvularia inaequalis, although with lower turnover rates for both Cl- and Br-. Substrate bromide was also found to inhibit the enzyme, a feature subsequently also noted for the chloroperoxidase from C. inaequalis. The gene encoding this enzyme was identified using DNA Southern blotting techniques and subsequently isolated and sequenced. A comparison is made between this vanadium chloroperoxidase and that of the fungus C. inaequalis both kinetically and at the sequence level. At the primary structural level the two chloroperoxidases share 68% identity, with conservation of all active site residues.
Barnett
P
P
Department of Biochemistry, E. C. Slater Institute, University of Amsterdam, Plantage Muidergracht 12, 1018 TV, Amsterdam, The Netherlands.
Hemrika
W
W
Dekker
H L
HL
Muijsers
A O
AO
Renirie
R
R
Wever
R
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D001965:Bromides / Q000378:metabolism; D002711:Chloride Peroxidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D003512:Cyclohexanones / Q000378:metabolism; D007700:Kinetics; D003904:Mitosporic Fungi / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D015183:Restriction Mapping; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014639:Vanadium
D001965:Bromides; D002712:Chlorides; D003512:Cyclohexanones; D014639:Vanadium; C006991:chlorodimedone; D002711:Chloride Peroxidase