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Carmichael Wallace

DPhil (Oxon)


Post-Retirement Appointment

Department member since 1987

Tupper 10-N3
902-494-1118
carmichael.wallace@dal.ca

Research:

Protein Engineering: Cytochrome c


Research Areas

Protein engineering allows us to change the amino acid sequence of a protein in specific predetermined ways. The reasons for doing so include understanding the relationship between a protein's structure and its function; labelling the protein for structural or radiotracer experiments; or deliberate modification of a protein's functional properties, for industrial or clinical use. Formerly, protein engineers operated at the level of the protein, using a wide variety of chemical means to change its structure. Of these the most powerful is protein semisynthesis (14,15). Now, site-directed mutagenesis of cloned genes can change the codon for a specific amino acid, so that subsequent expression of the altered gene yields an engineered protein. This technique has become the method of choice for most proteins, except where a semisynthetic route is already well established or where the experimental goal is difficult to attain by genetic means, for example, the insertion of a non-coded amino acid (15). Our work has been concerned both with the development of techniques of protein engineering by semisynthesis (14), and their use in answering questions about structure-function relationships in the respiratory chain component cytochrome c (8). We continue projects designed to understand the mechanism of electron transfer between the protein and its physiological partners (1), the way in which the nature of the protein shell establishes the internal dielectric (10) and modulates the properties of the haem centre (2,4,5). In investigations of the way the protein interacts with phospholipid membranes we have revealed a novel type of interaction, the extended lipid anchorage(7) and have recently proposed a structural mechanism(3). We continue investigations of this phenomenon, not least because of the potential relevance to the process of apotosis.

Lab Personnel

Bruce Stewart Lab Manager

Publications

  1. Black, K.M. and Wallace, C.J.A. , (2007) Probing the role of the conserved β-II turn, Pro76/Gly77 of mitochondrial cytochrome c. Biochem. Cell Biol 85:366-374 [PubMed]
  2. Dragomir, I., Hagarman, A., Wallace, C. and Schweitzer-Stenner, R. , (2007) Optical band splitting and electronic perturbations of the heme chromophore in cytochrome c at room temperature probed by visible electronic circular dichroism spectroscopy. Biophysical Journal 92:989-998 [PubMed]
  3. Kalanxhi, E. and Wallace, C.J.A., (2007) Cytochrome c impaled: investigation of the extended lipid anchorage of cytochrome c to mitochondrial membranes models Biochem. J. 407:179-187 [PubMed]
  4. Schweitzer-Stenner,R. Huang,Q., Hagasman,A.,Laberge,M. and Wallace, C. J. A. , (2007) Static normal coordinate deformations of the heme group in mutants of ferrocytochrome c from Saccharomyces cerevisiae probed by resonance Raman spectroscopy. J.Phys.Chem.B III:6527-6533. [PubMed]
  5. Schweitzer-Stenner, R., Levantino, M., Cupane, A., Wallace, C., Leberge, M. and Huang, Q., (2006) Functionally relevant electric field-induced perturbations of the prosthetic group of yeast ferro-cytochrome c mutants obtained from a vibronic analysis of low-temperature absorption spectra. J. Phys. Chem. B. 110:12155-12161. [PubMed]
  6. Blouin C, Guillemette JG, Wallace CJ., (2002) Probing electrostatic interactions in cytochrome c using site-directed chemical modification. Biochem. Cell. Biol. 80(2):197-203 [PubMed]
  7. Tuominen,E.K.J., Wallace, C.J.A. and Kinnunen,P.K.J., (2002) Phospholipid-Cytochrome c interaction:Evidence for the extended lipid anchorage. J. Biol. Chem. 277:8822-8826 [PubMed]
  8. Black, K.M., Clark-Lewis, I. and Wallace, C.J.A., (2001) The conserved tryptophan in cytochrome c: importance of the unique side chain features of the indole moiety. Biochem. J. 359:715-720 [PubMed]
  9. Parrish, J.C., Guillemette, J.G. and Wallace, C.J.A., (2001) A tale of two charges: distinct roles for an acidic and a basic amino acid in the structure and function of cytochrome c. Biochem. Cell. Biol. 79:83-91 [PubMed]
  10. Blouin, C. and Wallace, C.J.A., (2001) Protein matrix and dielectric effect in cytochrome c. J. Biol. Chem. 276:28814-28818 [PubMed]
  11. Tuominen, E.K.J., Zhu, K., Wallace, C.J.A., Clark-Lewis, I., Craig, D.B., Rytomaa, M. and Kinnunen, P.K.J., (2001) ATP induces a conformational change in lipid-bound cytochrome c. J. Biol. Chem. 276:19356-19362 [PubMed]
  12. Blouin, C., Guillemette, J.G., Wallace, C., (2001) Resolving the individual components of a pH-induced conformational change. Biophys J. 81(4):2331-2338. [PubMed]
  13. Parrish JC, Guillemette JG, Wallace CJ., (2001) Contribution of leucine 85 to the structure and function of Saccharomyces cerevisiae iso-1 cytochrome c. Biochem Cell Biol. 79(4):517-24 [PubMed]
  14. Wallace, C.J.A., (2000) Protein Engineering by Semisynthesis. CRC Press Boca Raton. FL:
  15. Wallace, C.J.A. and Clark-Lewis, I., (2000) Site-specific independent double-labelling of proteins with reporter atoms. Biochem. Cell. Biol. 78:79-86 [PubMed]