Curvularia inaequalis

Simons BH, P Barnett, EGM Vollenbroek, HL Dekker, AO Muijsers, A Messerschmidt, R Wever (1995) Primary structure and characterization of the vanadium chloroperoxidase from the fungus Curvularia inaequalis. Eur J Biochem 229 566-574. 

Messerschmidt A, L Prade, R Wever (1997) Implications for the catalytic mechanism of the vanadium-containing enzyme chloroperoxodase from the fungus Curvularia inaequalis hy X-ray structures of the native and peroxide form. Biol Chem 378 309-315. 

Renirie R, W Hemrika, R Wever (2000) Peroxidase and phosphatase activity of active-site mutants of vanadium chloroperoxidase from the fungus Curvularia inaequalis. J Biol Chem 275 11650-11657. 

The ubiquitous hemoprotein chloroperoxidase (CPO) (1) continues to be of great mechanistic and practical interest following its isolation more than 40 years ago from Caldariomyces fumago (2138). The CPO gene from this filamentous fungus has been isolated and sequenced (2139), an active recombinant CPO has been produced (2140), and the crystal structure of this CPO has been determined (2141, 2142). The fungus Curvularia inaequalis contains a vanadium CPO, which has been characterized (primary and X-ray structure) (Fig. 4.1) (2143-2147), as has the vanadium haloperoxidase from Corallina officinalis (2324). This enzyme has also been studied by density functional theory lending support to the proposed mechanism of action (Scheme 4.1) (2325). A related vanadium CPO, which shares 68% primary structural identity with the Curvularia inaequalis CPO, is produced... 

Vanadium CPO from Curvularia inaequalis has also been the object of both experimental (2146, 2172-2175, 2329) (for an X-ray structure see Fig. 4.1) and theoretical studies (2176) to understand the biohalogenation operation of this enzyme. A reasonable mechanism has emerged from these data (Scheme 4.2) (active site amino acids and H-bonds are deleted for clarity). The nature of the halide-vanadium intermediate is unknown. 

Despite the enormous versatility and efficiency of CPO in organic synthesis, the natural functions of this enzyme are no less important. In addition to its role in the biosynthesis of caldariomycin and other metabolites (I). CPO is involved in the degradative recycling of humic and fulvic acids (315, 412, 2100, 2108, 2111-2113, 2234, 2235). Both Caldariomyces fumago and Curvularia inaequalis CPO, which... 

Simons BH, Barnett P, Vollenbroek EGM, Dekker HL, Muijsers AO, Messerschmidt A, Wever R (1995) Primary Structure and Characterization of the Vanadium Chloroperoxidase from the Fungus Curvularia inaequalis. Eur J Biochem 229 566... 

Messerschmidt A, Prade L, Wever R (1997) Implications for the Catalytic Mechanism of the Vanadium-Containing Enzyme Chloroperoxidase from the Fungus Curvularia inaequalis by X-Ray Structures of the Native and Peroxide Form. Biol Chem 378 309... 

Macedo-Ribeiro S, Hemrika W, Renirie R, Wever R, Messerschmidt A (1999) X-Ray Crystal Structures of Active Site Mutants of the Vanadium-Containing Chloroperoxidase from the Fungus Curvularia inaequalis. J Biol Inorg Chem 4 209... 

Tanaka N, Hasan Z, Wever R (2003) Kinetic Characterization of Active Site Mutants Ser402Ala and Phe397His of Vanadium Chloroperoxidase from the Fungus Curvularia inaequalis. Inorg Chim Acta 356 288... 

A. Messerschmidt and R. Wever, X-ray structure of a vanadium-containing enzyme chloroperoxidase from the fungus Curvularia inaequalis, Proc. Natl. Acad. Sci. USA 1996, 93, 392-96. 

Figure 5.7 a Simplified catalytic cycle for vanadium chloroperoxidase, isolated from the fungus Curvularia inaequalis based on b crystal structures ofthe native enzyme and the peroxo intermediate [30,31], Thanks to Dr. Teunie van Herk for the enzyme structure image. 

Messershmidt, A., L. Prade, and R. Wever. 1998. Chloroperoxidase from Curvularia inaequalis x-ray structures of native and peroxide form reveal vanadium chemistry in vanadium haloperoxidases. ACS Symp. Ser. 711 186-201. 

Macedo-Ribeiro, S., Hemrika, W., Renirie, R., Wever, R. and Messerschmidt, A. (1999). X-ray crystal structure of active site mutants of the vanadium-containing chloroperoxidase from the fungus Curvularia inaequalis. Journal of Biological Inorganic Chemistry, 4,209-219. 

Hemrika W, Renirie R, Macedo-Ribeiro S et al (1999) Heterologous expression of the vanadium-containing chloroperoxidase from Curvularia inaequalis in Saccharomyces cerevisiae and site-directed mutagenesis of the active site residues His(496), Lys(353), Arg (360), and Arg(490). J Biol Chem 274 23820-23827... 

The X-ray structures of vanadium bromoperoxidases from the red seaweeds Corallina pilulifera and C. officinalis have also been determined and their structures are almost identical. The native structure of these enzymes is dodecameric and the structure is made up of 6 homo-dimers. The secondary stmcture of the chloroperoxidase from the ftmgus Curvularia inaequalis that will be discussed later can be superimposed with the Corallina hromoperoxidase dimer. Many of the a helices of each chloroperoxidase domain are structurally equivalent to the a helices in the Corallina hromoperoxidase dimer. This is in line with the evolutionary relationship between the haloperoxidases that will be discussed later. The disulfide bridges in the enzyme from A. nodosum are not found in the enzyme from Corallina and the two remaining cysteine residues are not involved in disulfide bonds. Additionally, in this enzyme binding sites are present for divalent cations that seem to be necessary to maintain the stmcture of the active site cleft. All the residues directly involved in the binding of vanadate are conserved in the algal bromoperoxidases. ... 

Fig. 79. Lifetime of lactose electrodes using (J-galactosidase from Bifidobacterium (1), Escherichia coli (crosslinked) (2), and Curvularia inaequalis (3).

Van Schijndel JWPM, Vollenbroek EGM and Wever R (1993) The chloroperoxidase from the fungus Curvularia inaequalis a novel vanadium enzyme. Biochim Biophys Acta 1161 249 - 256. 

Since vanadium chloroperoxidase from Curvularia inaequalis is structurally closely related to acid phosphatases and transition metal oxoanions are potent inhibitors of the related phytases, (Figure 10.8) [35,36], Sheldon and coworkers investigated the peroxidase activity of phytase from Aspergillus ficuum in the presence of sodium orthovanadate Na3V04 [37-39]. Oxidation of thioanisole with H2O2 proceeded to produce the sulfoxide in quantitative yield in the presence of [VO4]-phytase. The reaction rate showed saturation kinetics with respect to the vanadate concentration, indicating a maximum rate of 120pmol/h (TOF = 11 min ) and a dissociation constant for the vanadate ion of 15.4 pM. 

P-D-Galactosidases.—The p-D-galactosidase from Curvularia inaequalis adsorbed two molecules of Bright Orange KH the six sulphate groups introduced by the dye had little effect on the isoelectric point or catalytic activity of the enzyme. ... 

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