Abstract

Myeloperoxidase, a heme enzyme of polymorphonuclear neutrophils, will be purified and examined by a variety of spectroscopic means. Special characteristics of myeloper-oxidase is its ability to catalyze the oxidation of halide ion, such as chloride, bromide, and iodide ions, to hypohalite by hydrogen peroxide to kill the ingested organism. Since the heme group is the active center of this enzyme, the electronic properties of the heme irom, the environment of the heme group, and the effect of substrate binding (particularly chloride ion) on these properties will be elucidated in order to obtain the vital informations about the mechanism of action of the enzyme. The primary goals of this proposal are: (1) determination of the chloride binding site, (2) characterization of the structure of the heme group, (3) determination of the mode of the interactions between the heme group and apo-protein moeity, and (4) evaluation of the inequivalence between the heme groups by systematic utilization of light absorption, electron paramagentic resonance, proton- and chlorine-nuclear magnetic resonance, resonance Raman scattering, and kinetic spectroscopies. Elucidation of the molecular mechanism of the enzyme action of myeloperoxidase is essential for our understanding the bacteriocidal function of polymophonuclear leukocytes, which is vital for survival of mammalian species against bacterial infections.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM039492-08
Application #
3296509
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1989-02-01
Project End
1991-03-31
Budget Start
1990-04-01
Budget End
1991-03-31
Support Year
8
Fiscal Year
1990
Total Cost
Indirect Cost

  Institution

Name
Case Western Reserve University
Department
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106

  Publications

Matera, K M; Takahashi, S; Fujii, H et al. (1996) Oxygen and one reducing equivalent are both required for the conversion of alpha-hydroxyhemin to verdoheme in heme oxygenase. J Biol Chem 271:6618-24
Ishikawa, K; Takeuchi, N; Takahashi, S et al. (1995) Heme oxygenase-2. Properties of the heme complex of the purified tryptic fragment of recombinant human heme oxygenase-2. J Biol Chem 270:6345-50
Ito-Maki, M; Ishikawa, K; Matera, K M et al. (1995) Demonstration that histidine 25, but not 132, is the axial heme ligand in rat heme oxygenase-1. Arch Biochem Biophys 317:253-8
Brancaccio, A; Cutruzzola, F; Allocatelli, C T et al. (1994) Structural factors governing azide and cyanide binding to mammalian metmyoglobins. J Biol Chem 269:13843-53
Qin, J; La Mar, G N; Dou, Y et al. (1994) 1H NMR study of the solution molecular and electronic structure of engineered distal myoglobin His64(E7) Val/Val68(E11) His double mutant. Coordination of His64(E11) at the sixth position in both low-spin and high-spin states. J Biol Chem 269:1083-90
Takahashi, S; Wang, J; Rousseau, D L et al. (1994) Heme-heme oxygenase complex: structure and properties of the catalytic site from resonance Raman scattering. Biochemistry 33:5531-8
Takahashi, S; Wang, J; Rousseau, D L et al. (1994) Heme-heme oxygenase complex. Structure of the catalytic site and its implication for oxygen activation. J Biol Chem 269:1010-4
Hori, H; Fenna, R E; Kimura, S et al. (1994) Aromatic substrate molecules bind at the distal heme pocket of myeloperoxidase. J Biol Chem 269:8388-92
Lee, H C; Peisach, J; Dou, Y et al. (1994) Electron-nuclear coupling to the proximal histidine in oxy cobalt-substituted distal histidine mutants of human myoglobin. Biochemistry 33:7609-18
Sakan, Y; Ogura, T; Kitagawa, T et al. (1993) Time-resolved resonance Raman study on the binding of carbon monoxide to recombinant human myoglobin and its distal histidine mutants. Biochemistry 32:5815-24

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