1. BCMB – 8110 Control of Electron Transfer in Biology 1- Key Concepts -Transfer Potentials -Electron transfer cofactors 2- Overview of the electron transport chain - Complex I -Complex II -Complex III -Complex IV 3- Advanced Concepts in Protein Structure/Function -Mechanisms of redox control -Mechanisms of proton transfer -Mechanisms of electron transfer

2. Transfer Potential and the Meaning of Life It’s all about energy!

3. Free Energy and Reduction Potential

4. Transfer Potential

5. Electron Carriers – Coenzyme Q

6. Electron Carriers – Iron Sulfur Clusters

7. Universal, Mobile Electron Carriers – Ferredoxins

8. Electron Carriers – Low Potential Ferredoxins

9. Electron Carriers – Rieske Type Iron Sulfur Clusters

10. Electron Carriers – Cytochromes

12. Electron Carriers – Blue Copper Proteins

13. Electron Carriers – Flavoprotein

14. Electron Storage in Flavins

15. Complex III

16. Cytochrome bc 1 Complex (Cont.)

19. Controlling Reduction Potentials, ElectronTransfer And Proton Transfer Rule #1, In most cases, especially for complex metallocenters, proton and electron transfer are coupled.

20. Redox Control – Rubredoxin

27. Redox Control – Nitrogenase

31. Structural Models of the P-Cluster Peters et al. Biochemistry (1997) 36 1181-1187

32. Redox Control – Nitrogenase

33. -360 -340 -320 -300 -280 -260 -240 -220 -200 E m2 (mV) 9.08.58.07.57.06.56.05.5 pH Slope = -53 mV / pH pH-dependence for the P Redox Couple 2+/1+

34. Model for P-Cluster Redox and Proton Transfer Reactions P 2+ P 1+ (H+) P 2+ (H+) P 1+ PNPN P N (H+) E m2 E m2H E m1 E m1H pK a < -348 mV > -224 mV < 6.0 > 8.5 -310 mV

35. Structural Models of the P-Cluster Peters et al. Biochemistry (1997) 36 1181-1187

36. e- 8 H + + 8e- + N 2 2 NH 3 + H 2 e- H+H+ P N P 1+ P 2+ pH 7.0 -310 mV-260 mV P N P 1+ P 2+ -310 mV pH 8.0

37. Cytochrome Oxidase- Proton Transfer

38. Coupled Proton/Electron transfer – Cytochrome Oxidase

39. Coupled Proton/Electron transfer – Cytochrome Oxidase

40. Coupled Proton/Electron transfer – Cytochrome Oxidase

41. Coupled Proton/Electron transfer – Cytochrome Oxidase

42. COX + Cyc c + broken beef heart mitochondria. Capitanio et al. Biochemistry 42(16) p.4607-4612 Coupled Proton/Electron transfer – Cytochrome Oxidase

43. Coupled Proton/Electron transfer – Cytochrome Oxidase

44. Electron Transfer – Theory and Experiment