Chemistry Speaker Tour

2021-2022 Speaker Tour

Chérif F. Matta

Department of Chemistry 
Mount Saint Vincent University

Speaker Tour Dates and Locations

2021

  • Oct. 21 CBU (virtual)
  • Oct. 26 MUN (in-person)
  • Nov. 4 Acadia (in-person)
  • Nov. 19 UdeM (in-person)
  • Nov. 22 MtA (in-person)

2022

  • March 25 StFX (virtual)
  • Jan. 28 UNB-F (in-person)

   

Presentation – ATP synthase: An enzyme machine and more. Perhaps much more!

This talk underscores the biological role of the electric potentials of enzymes beyond their roles as catalysts. Recent structures of ATP synthase from 5 species are used to compare their electrostatic potentials (ESP) and fields. Striking patterns emerge including a role of ATP synthase beyond its known catalytic function in mitochondrial energy transduction. ATP synthase’s intrinsic ESP is of the order of magnitude of the chemiosmotic ESP and hence cannot be ignored. It is suggested that an additional term must, thus, be added in the traditional ΔG expression of chemiosmotic theory to account for the contribution of ATP synthase itself to the energy of translocation of every proton. Thus, we can assign three complementary roles to ATP synthase:

  1. Its putative role, and that is the catalysis (lowering the ΔG ‡ ) of the reaction of phosphorylation of ADP into ATP.
  2. A novel role, which is, altering the ΔG of the reaction of translocation of protons from the inter-membrane gap to the mitochondrial matrix.
  3. Another novel role, and that is, to create a potential barrier regulating the rate of proton translocation itself.

Said differently, due to the enzyme’s very structure, ATP synthase functions over and above its role as an enzyme as a biological catalyst. How this term has been overlooked will be discussed in the context of a larger research programme.

See abstract images (image 1, image 2)

[1] Vigneau, J. N.; Fahimi, P.; Ebert, M.; Cheng, Y.; Tannahill, C.; Muir, P.; Nguyen-Dang, T.-T.; Matta, C. F. (2021), manuscript in final stage of preparation. [2] Fahimi, P.; Matta, C. F. (2021). Phys. Biol. 18, Article #04LT01, pp. 1-6. [3] Fahimi, P.; Matta, C. F. (2021) in review (arXiv:2106.04796 [physics.bio-ph] 10 Jun (2021). [4] Nasr, M. A.; Dovbeshko, G. I.; Bearne, S. L.; El-Badri, N.; Matta, C. F. (2019). BioEssays 41, 1900055. [5] Matta, C. F.; Massa, L. (2017). J. Phys. Chem. A 121, 9131.

Chérif F. Matta, BPharmSci (Hons), Dipl., PhD, HDR, FRSA, FRSB, FInstP, FRSC is Professor and Chair of the Dept. of Chemistry & Physics at Mount Saint Vincent University. Chérif obtained a Bachelor of Pharmaceutical Science from Alexandria University (Egypt), a PhD in theoretical and quantum chemistry from McMaster University from the school of Richard F. W. Bader, and a Habilitation to Direct Research (HDR) from the Université de Lorraine (France) in the laboratory of crystallographer Claude Lecomte. Postdoctoral training opportunities opened for him at the University of Toronto under John C. Polanyi, and then at Dalhousie University with Russell J. Boyd. Professor Matta counts ca. 160 publications including two edited books and two monographs (in prep.), and has given 200 seminars and conference presentations in 30 countries. His research ranges from theoretical and computational chemistry focusing on the effects of electric fields on biochemical reactions to mitochondrial biophysics. He is an elected Fellow of the Royal Society of Chemistry (FRSC), of the Institute of Physics (FInstP), of the Royal Society of Biology (FRSB), and of the Royal Society of the Arts (FRSA). (Please visit: https://www.cmatta.ca/).

Dr. Christina Bottaro

Department of Chemistry
Memorial University of Newfoundland

Speaker Tour Dates and Locations

TBD