1. Britton Chance: His Life, Times, and Legacy June 3-4, 2011 University of Pennsylvania First With Creativity from masers and lasers to tunneling and P680, superoxide and beyond Robert A. Floyd Oklahoma Medical Research Foundation

2. BC’s Early papers – A Coalescing Interest Stable Spectrophotometry of Small Density Changes Chance, B – Rev Sci Instrum 1947 18(9) 601-9 The Enzyme-Substrate Compounds of Catalase and Peroxides Chance, B – Nature 1948 161 (4102) 914-7 Effects of Oxygen upon Light Absorption by Green Algae Chance, B and Strekler, B – Nature 1957 180 (4589) 749-50 Cytochrome Reactions in Chromatuim Olson, JM and Chance, B – BBA 1958 28(1) 227-8

3. BC’s Early papers – A Coalescing Interest Creative Spectroscopist Inquisitive View into Living Systems - All Dynamic Chromophores of Living Systems were of Interest - Seminal Observations were made in several important areas - Catalyzed more research at JF and in many other laboratories Hydrogen Peroxide Driven Reactions Involving Heme Proteins Photosynthetic Systems – Light Driven Reactions Oxygen Driven Dark Reactions/Mitochondrial Reactions

4. Important Observations in Oxygen Biology 1968-1972 McCord/FridovichO2O2 SOD Discovered Boveris/Loschen/Chance MwMw H2O2H2O2 Mitochondrial Mechanisms Kasha/Kahn 1O21O2 Bimol-mediated formation of photons Floyd/DeVault/Chance cytb 559 P 680 + Primary photosystem II Reactions Temperature Independent at 220-80°K

6. Experimental Set Up Ruby Laser Q-switched with spinning prism PM Red laser light 690nm Optical Cell High pressure (4 ATM) hydrogen Green laser First Antistokes line ~540nm Grating Green laser light Sample Analyzing light beam Grating P 680 CL hνhν cytb 559 e Temperature independent Floyd, Chance and DeVault; BBA 226;103 (1971) Laser t 1/2 =4.5 msec 680 nm + 220°K 80°K

7. Standard electrode potential, V + 1.0 + 0.8 + 0.6 + 0.4 + 0.2 0.0 - 0.2 - 0.4 - 0.6 Photosytem I Photosytem II Z NADPH NADPH + P680 H2OH2O P700 Plastocyanin Cyt f Reductase Ferredoxin P430 Shunt pathway of cyclic electron flow e-e- e-e- e-e- Plastoquinone ADP e-e- ATP Pi+Pi+ hv 2H + ½O 2 e-e- Green Plant Photosynthesis* Cyt b 563 Adapted from A. Lehninger Principles of Biochemistry

8. Reactive Oxygen species (ROS) in Biology and Medicine -Major Area in Biomedical Research -Evolved from Damaging Species to Sophisticated Signaling System O2O2 MwMw H2O2H2O2 3O23O2 cytb 559 P 680 + Alpha and gamma–tochopherols in Diseases A. Azzi Molecular Mechanisms MwMw H2O2H2O2 A. Boveris Oxidative Stress H. Sies Specific Traps for ROS Nitrones/salicylate ROS in Cancer 8-OHdG Anticancer Drugs Nitrones /OKN-007 Translational Research Effort ROS in Stroke Anti-stroke Drugs Nitrones/NXY-059 MB 1O21O2 hv RNA Virus Inactivation HIV, WNV, DENV Inactivated virus antigen Novel vaccines

11. S N N CH 3 N + Cl - H MB = Methylene Blue 1 MB 3 MB MB 3O23O2 1O21O2 light Singlet Oxygen RNA Viruses HIV ~ 0.028* West Nile Virus - Hepatitis C Virus - EC 50 (μM) Methylene Blue plus Light Inactivates RNA Viruses *Table 4 U.S. Patent 6,346,529 Potently produces 8-OHdG and 8-OHG 8-hydroxy-2’deoxyguanosine in DNA 8-hydroxy-guanosine in RNA