@article {12576477,
	title = {Examining the role of glutamic acid 183 in chloroperoxidase catalysis},
	journal = {J Biol Chem},
	volume = {278},
	number = {16},
	year = {2003},
	note = {Yi, Xianwen Conesa, Ana Punt, Peter J Hager, Lowell P GM 07768/GM/NIGMS NIH HHS/United States Research Support, U.S. Gov{\textquoteright}t, P.H.S. United States The Journal of biological chemistry J Biol Chem. 2003 Apr 18;278(16):13855-9. Epub 2003 Feb 7.},
	pages = {13855-9},
	abstract = {Site-directed mutagenesis has been used to investigate the role of glutamic acid 183 in chloroperoxidase catalysis. Based on the x-ray crystallographic structure of chloroperoxidase, Glu-183 is postulated to function on distal side of the heme prosthetic group as an acid-base catalyst in facilitating the reaction between the peroxidase and hydrogen peroxide with the formation of Compound I. In contrast, the other members of the heme peroxidase family use a histidine residue in this role. Plasmids have now been constructed in which the codon for Glu-183 is replaced with a histidine codon. The mutant recombinant gene has been expressed in Aspergillus niger. An analysis of the produced mutant gene shows that the substitution of Glu-183 with a His residue is detrimental to the chlorination and dismutation activity of chloroperoxidase. The activity is reduced by 85 and 50\% of wild type activity, respectively. However, quite unexpectedly, the epoxidation activity of the mutant enzyme is significantly enhanced approximately 2.5-fold. These results show that Glu-183 is important but not essential for the chlorination activity of chloroperoxidase. It is possible that the increased epoxidation of the mutant enzyme is based on an increase in the hydrophobicity of the active site.},
	keywords = {Aspergillus niger/metabolism Catalase/metabolism Catalysis Chloride Peroxidase/*chemistry/*metabolism Chlorine/metabolism Chromatography, Ion Exchange Circular Dichroism Crystallography, Polyacrylamide Gel Fungi/enzymology Glutamic Acid/*chemistry Histidine/chemistry/metabolism Hydrogen-Ion Concentration Immunoblotting Isoelectric Focusing Mutation Oxidoreductases/metabolism Plasmids/metabolism, X-Ray Electrophoresis},
	url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=12576477},
	author = {Yi, X. and A. Conesa and Punt, P. J. and Hager, L. P.}
}
@article {11278701,
	title = {Expression of the Caldariomyces fumago chloroperoxidase in Aspergillus niger and characterization of the recombinant enzyme},
	journal = {J Biol Chem},
	volume = {276},
	number = {21},
	year = {2001},
	note = {Conesa, A van De Velde, F van Rantwijk, F Sheldon, R A van Den Hondel, C A Punt, P J Research Support, Non-U.S. Gov{\textquoteright}t United States The Journal of biological chemistry J Biol Chem. 2001 May 25;276(21):17635-40. Epub 2001 Feb 22.},
	pages = {17635-40},
	abstract = {The Caldariomyces fumago chloroperoxidase was successfully expressed in Aspergillus niger. The recombinant enzyme was produced in the culture medium as an active protein and could be purified by a three-step purification procedure. The catalytic behavior of recombinant chloroperoxidase (rCPO) was studied and compared with that of native CPO. The specific chlorination activity (47 units/nmol) of rCPO and its pH optimum (pH 2.75) were very similar to those of native CPO. rCPO catalyzes the oxidation of various substrates in comparable yields and selectivities to native CPO. Indole was oxidized to 2-oxindole with 99\% selectivity and thioanisole to the corresponding R-sulfoxide (enantiomeric excess >98\%). Incorporation of (18)O from labeled H(2)18O(2) into the oxidized products was 100\% in both cases.},
	keywords = {Aspergillus niger/enzymology/genetics Catalysis Chloride Peroxidase/biosynthesis/*genetics Fungal Proteins/biosynthesis/*genetics Recombinant Proteins/biosynthesis/genetics Substrate Specificity},
	url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=11278701},
	author = {A. Conesa and van De Velde, F. and van Rantwijk, F. and Sheldon, R. A. and van den Hondel, C. A. and Punt, P. J.}
}
