`Molecular Biochemistry I

Electron Transfer Chain


Textbook Reading: Biochemistry, 3rd Edition, by Voet & Voet, pages 57-60, 555-556, 571-574, and Chapter 22.

Some recent articles (optional reading): 
E. C. Slater (2003) "Keilin, cytochrome, and the respiratory chain," J. Biol. Chem. 278: 16455-16461.
A. Matsuno-Yagi & T. Yagi (2001) "Introduction: Complex I - an L-shaped black box," J. Bioenerget. Biomembr. 33: 155-157, and accompanying articles.
A. Videira & M. Duarte (2002) "From NADH to ubiquinone in Neurospora mitochondria," Biochim. Biophys. Acta 1555: 187-191.
T. Friedrich & B. Bttcher (2004) "The gross structure of the respiratory complex I: a Lego system," Biochim. Biophys. Acta 1608: 1-9.
G. Cecchini (2003) "Function and structure of complex II of the respiratory chain," Annu. Rev. Biochem. 72: 77-109.
C. E. Cooper (2002) "Nitric oxide and cytochrome oxidase: substrate, inhibitor or effector?" Trends in Biochem. Sci. 27: 33-39.
P. Sarti, A. Giuffr, M. C. Barone, E. Forte, D. Mastronicola & M. Brunori (2003) "Nitric oxide and cytochrome oxidase: reaction mechanisms from the enzyme to the cell" Free Radical Biol. & Med. 34: 509-520.
A. Barrientos, M. H. Barros, I. Valnot, A. Rtig, P. Rustin & A. Tzagoloff (2002) "Cytochrome oxidase in health and disease," Gene 286: 53-63.
W. Xu, I. G. Charles & S. Moncada (2005) "Nitric oxide: orchestrating hypoxia regulation through mitochondrial respiration and the endoplasmic reticulum stress response," Cell Res. 15: 63-65.
M. Turunen, J. Olsson & G. Dallner (2004) "Metabolism and function of coenzyme Q," Biochim. Biophys. Acta 1660: 171-199.
D. C. Johnson, D. R. Dean, A. D. Smith & M. K. Johnson (2005) "Structure, function, and formation of biological iron-sulfur clusters," Annu. Rev. Biochem. 74: 247-281.
U. Brandt (2006) "Energy converting NADH:quinone oxidoreductase (complex I)," Annu. Rev. Biochem. 75: 69-92.
L. Sazanov & P. Hinchcliffe (2006) "Structure of the hydrophilic domain of respiratory complex I from Thermus thermophilus," Science 311: 1430-1435.
S. Yoshikawa, K. Muramoto, K. Shinzawa-Itoh, H. Aoyama, T. Tsukihara, T. Ogura, K. Shimokata, Y. Katayama & H. Shimada (2006) "Reaction mechanism of bovine heart  cytochrome c oxidase," Biochim. Biophys. Acta 1757: 395-400.
G. Lenaz, R. Fato, G. Formiggini & M. L. Genova (2007) "The role of coenzyme Q in mitochondrial electron transport," Mitochondrion 7S S8-S33.
E. J. Boekema & H.-P. Braun (2007) "Supramolecular structure of the mitochondrial oxidative phosphorylation system," J. Biol. Chem. 282: 1-4.
C. C. Moser, T. A Farid, S. E. Chobot & P. L. Dutton (2006) "Electron tunneling chains of mitochondria," Biochim. Biophys. Acta 1757: 1096-1109.

II. Potential Test Questions:

1. Summarize the composition of each of the respiratory chain complexes I, III, and IV. Diagram the pathway of electron transfer in the mitochondrial inner membrane from matrix NADH to oxygen, including the smaller electron carriers, coenzyme Q and cytochrome c. Where in the pathway does complex II donate electrons derived from succinate in Krebs cycle to the respiratory chain?

2. What is the special role of FMN in complex I? What intermediate is essential to this role? Write out the redox reactions in which FMN is reduced, and then reoxidized, during electron transfer in complex I.

3.a. Write a summary equation for the reaction catalyzed by Cytochrome Oxidase (Complex IV), listing reactants and products. What metal centers function in this reaction? What is the overall role of each of these?
   b. Diagram and describe how heme a is held in place within the complex. What atoms interact with the iron atoms of heme a and a3?

Copyright 1998-2007 by Joyce J. Diwan. All rights reserved.

Lecture notes on
Electron Transfer Chain

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Electron Transfer     

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