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Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide.

Publication ,  Journal Article
Bonaventura, C; Godette, G; Tesh, S; Holm, DE; Bonaventura, J; Crumbliss, AL; Pearce, LL; Peterson, J
Published in: The Journal of biological chemistry
February 1999

Previous studies showed that CO/H2O oxidation provides electrons to drive the reduction of oxidized hemoglobin (metHb). We report here that Cu(II) addition accelerates the rate of metHb beta chain reduction by CO by a factor of about 1000. A mechanism whereby electron transfer occurs via an internal pathway coupling CO/H2O oxidation to Fe(III) and Cu(II) reduction is suggested by the observation that the copper-induced rate enhancement is inhibited by blocking Cys-beta93 with N-ethylmaleimide. Furthermore, this internal electron-transfer pathway is more readily established at low Cu(II) concentrations in Hb Deer Lodge (beta2His --> Arg) and other species lacking His-beta2 than in Hb A0. This difference is consistent with preferential binding of Cu(II) in Hb A0 to a high affinity site involving His-beta2, which is ineffective in promoting electron exchange between Cu(II) and the beta heme iron. Effective electron transfer is thus affected by Hb type but is not governed by the R left arrow over right arrow T conformational equilibrium. The beta hemes in Cu(II)-metHb are reduced under CO at rates close to those observed for cytochrome c oxidase, where heme and copper are present together in the oxygen-binding site and where internal electron transfer also occurs.

Duke Scholars

Published In

The Journal of biological chemistry

DOI

EISSN

1083-351X

ISSN

0021-9258

Publication Date

February 1999

Volume

274

Issue

9

Start / End Page

5499 / 5507

Related Subject Headings

  • Oxidation-Reduction
  • Methemoglobin
  • Kinetics
  • Humans
  • Heme
  • Electron Transport
  • Electron Spin Resonance Spectroscopy
  • Cysteine
  • Copper
  • Carbon Monoxide
 

Citation

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Bonaventura, C., Godette, G., Tesh, S., Holm, D. E., Bonaventura, J., Crumbliss, A. L., … Peterson, J. (1999). Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide. The Journal of Biological Chemistry, 274(9), 5499–5507. https://doi.org/10.1074/jbc.274.9.5499
Bonaventura, C., G. Godette, S. Tesh, D. E. Holm, J. Bonaventura, A. L. Crumbliss, L. L. Pearce, and J. Peterson. “Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide.The Journal of Biological Chemistry 274, no. 9 (February 1999): 5499–5507. https://doi.org/10.1074/jbc.274.9.5499.
Bonaventura C, Godette G, Tesh S, Holm DE, Bonaventura J, Crumbliss AL, et al. Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide. The Journal of biological chemistry. 1999 Feb;274(9):5499–507.
Bonaventura, C., et al. “Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide.The Journal of Biological Chemistry, vol. 274, no. 9, Feb. 1999, pp. 5499–507. Epmc, doi:10.1074/jbc.274.9.5499.
Bonaventura C, Godette G, Tesh S, Holm DE, Bonaventura J, Crumbliss AL, Pearce LL, Peterson J. Internal electron transfer between hemes and Cu(II) bound at cysteine beta93 promotes methemoglobin reduction by carbon monoxide. The Journal of biological chemistry. 1999 Feb;274(9):5499–5507.

Published In

The Journal of biological chemistry

DOI

EISSN

1083-351X

ISSN

0021-9258

Publication Date

February 1999

Volume

274

Issue

9

Start / End Page

5499 / 5507

Related Subject Headings

  • Oxidation-Reduction
  • Methemoglobin
  • Kinetics
  • Humans
  • Heme
  • Electron Transport
  • Electron Spin Resonance Spectroscopy
  • Cysteine
  • Copper
  • Carbon Monoxide