Heme proteins are ideally suited for detailed structure-function studies using protein engineering techniques. Most well studied heme proteins (globins, c-and b-type cytochromes, peroxidases, P450) all have exactly the same heme prosthetic group yet each exhibits very different and very clearly defined functions. These differences are dictated by the interaction between the protein and heme much of which has been deciphered through a variety of spectral probes and x-ray crystallography. Therefore, there are some specific questions that can be asked regarding the relationship between structure and function in heme proteins. The research in this proposal will focus on peroxidase. Recombinant systems have been developed for two peroxidases: cytochrome c and ascorbate peroxidase. Ascorbate peroxidase is the first and, to date, only eukaryotic heme enzyme that has been expressed as a holo-enzyme in E. coli. One goal of this proposal is to fully characterize the ascorbate peroxidase and then use mutagenesis to study its function. This will complement the ongoing work on cytochrome c peroxidase where mutagenesis will be used to probe the mechanism of intraprotein electron transfer. Since the substrate specificities of both peroxidases are markedly different and we have the crystal structures of both, we are in a good position to employ mutagenesis methods to decipher what structural features control substrate specificity.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM042614-09
Application #
2734636
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1989-07-01
Project End
2000-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
9
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Poulos, Thomas L (2014) Heme enzyme structure and function. Chem Rev 114:3919-62
Tripathi, Sarvind; O'Neill, Maura J; Wilks, Angela et al. (2013) Crystal structure of the Pseudomonas aeruginosa cytoplasmic heme binding protein, Apo-PhuS. J Inorg Biochem 128:131-6
Jasion, Victoria S; Poulos, Thomas L (2012) Leishmania major peroxidase is a cytochrome c peroxidase. Biochemistry 51:2453-60
Martell, Jeffrey D; Deerinck, Thomas J; Sancak, Yasemin et al. (2012) Engineered ascorbate peroxidase as a genetically encoded reporter for electron microscopy. Nat Biotechnol 30:1143-8
Jasion, Victoria S; Doukov, Tzanko; Pineda, Stephanie H et al. (2012) Crystal structure of the Leishmania major peroxidase-cytochrome c complex. Proc Natl Acad Sci U S A 109:18390-4
Jensen, Lyndal M R; Meharenna, Yergalem T; Davidson, Victor L et al. (2012) Geometric and electronic structures of the His-Fe(IV)=O and His-Fe(IV)-Tyr hemes of MauG. J Biol Inorg Chem 17:1241-55
Benabbas, Abdelkrim; Karunakaran, Venugopal; Youn, Hwan et al. (2012) Effect of DNA binding on geminate CO recombination kinetics in CO-sensing transcription factor CooA. J Biol Chem 287:21729-40
Jasion, Victoria S; Polanco, Julio A; Meharenna, Yergalem T et al. (2011) Crystal structure of Leishmania major peroxidase and characterization of the compound i tryptophan radical. J Biol Chem 286:24608-15
Meharenna, Yergalem T; Doukov, Tzanko; Li, Huiying et al. (2010) Crystallographic and single-crystal spectral analysis of the peroxidase ferryl intermediate. Biochemistry 49:2984-6
Sundaramoorthy, Munirathinam; Gold, Michael H; Poulos, Thomas L (2010) Ultrahigh (0.93A) resolution structure of manganese peroxidase from Phanerochaete chrysosporium: implications for the catalytic mechanism. J Inorg Biochem 104:683-90

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