Kevin Redding

TEMPE Campus


Kevin Redding received a B.A. in biochemistry from Rice University in 1987 and a Ph.D. degree in biochemistry from Stanford University in 1993, working with Robert Fuller.  He was an National Science Foundation (NSF) Plant Biology Postdoctoral Fellow and a Human Frontiers in Science Postdoctoral Fellow and worked with Jean-David Rochaix at the University of Geneva.  He started his academic career at the University of Alabama in 1998, received a DuPont Young Professor award and NSF CAREER award. After a one-year stint at the Institut de Biologie Physico-Chimique in Paris as a Fulbright Scholar, he joined ASU in 2008. His current research interests are in structure/function studies of photosynthetic reaction centers, re-engineering photosynthetic electron transfer, and fundamental processes in heliobacteria.


  • Ph.D. Biochemistry, Stanford University 1993
  • B.A. Biochemistry, Rice University 1987

Research Interests

The Redding group works on the function of photochemical reaction centers, the key components in the energy conversion process of photosynthesis. As a model system, we are using Photosystem 1 (PS1), a multi-subunit membrane protein complex that uses the energy of absorbed photons to promote transmembrane electron transfer. The core of PS1 is a heterodimer of two homologous, integral membrane polypeptides, which form a framework holding the cofactors involved in electron transport.

1) Structure/function studies: One of the most interesting questions in biochemistry is "How does the protein environment affect the properties of bound molecules?" The phylloquinone cofactor embedded in PS1 is an excellent example. It is much more reducing when bound in PS1 than when isolated in organic solvent. Thus, the protein is able to "tune" the properties of the quinone so that it functions as a good intermediate in electron transfer. We are using site-directed mutagenesis to change amino acid residues that interact with the phylloquinone, and thus change its properties. Characterization of the mutants involves use of advanced techniques, such as electron paramagnetic resonance and kinetic spectroscopy.

2) Engineering electron transfer: The symmetric structure of PS1 includes two possible pathways of electron transfer. By changing amino acids around one quinone or the other, we have shown that both pathways can be used. We are altering the two quinone sites to see how the differences between them translate into different electron transfer rates. We hope to alter the sites enough to allow binding of alternate target molecules, which may lead to light-powered biomolecular devices capable of reductively destroying environmental pollutants, etc. We are also trying to see if we can control which pathway the electrons take by modify the environment near the electron donors.

3) Electron transfer processes in Heliobacteria: Our newest project involves engineering of the most primitive photosynthetic organism currently known. They use a homodimeric reaction center that is superficially similar to PS1 in several ways. The genome of Heliobacterium modesticaldum, the only thermophilic organism in this group, was recently determined in a collaboration between TGen and ASU ( We have recently developed a transformation system for this organism, and are using it to delete key proteins involved in photosynthetic electron transfer and biosynthesis of cofactors. Long-term goals include: gaining insight into the evolution of asymmetric photosynthetic reaction centers, assessing alternative roles for quinones in this group of organisms, and optimizing their production of hydrogen.


  • Johnson, W.A., Redding, K.E.  Reconstitution of the heliobacterial photochemical reaction center and cytochrome c(553) into a proteoliposome system.  Photosynth. Res. 143 (3), 241-250 (2020).
  • Orf, G.S., Redding, K.E.  Expression and purification of affinity-tagged variants of the photochemical reaction center from Heliobacterium modesticaldum.  Photosynthesis Research.  142 (3) 335-348 (2019).
  • Baker, P.L., Orf, G.S., Khan, Z., Espinoza, L., Leung, S., Kevershan, K., Redding, K.E., A Molecular Biology Tool Kit for the Phototrophic Firmicute Heliobacterium modesticaldum.  Applied and Environmental Microbiology.  85 (19) (2019).
  • Kashey, T., D.D. Luu, J.B. Cowgill, P.L. Baker, K.E. Redding*. Light-driven quinone reduction in heliobacterial membranes. Photosynth. Res., in press (2018).
  • Badshah SL, Sun J, Mula S, Gorka M, Baker P, Luthra R, Lin S, van der Est A, Golbeck JH, Redding KE. Mutations in algal and cyanobacterial Photosystem I that independently affect the yield of initial charge separation in the two electron transfer cofactor branches. Biochim Biophys Acta 1859:42-55 (2018).
  • Gisriel, C., I. Sarrou, B. Ferlez, J.H. Golbeck, K.E. Redding, R. Fromme.  Structure of a symmetric photosynthetic reaction center-photosystem. Science 357:1021-1025 (2017).
  • Ferlez, B., Cowgill, J., Dong, W., Gisriel, C., Lin, S., Flores, M., Walters, K., Cetnar, D., Redding, K. E., and Golbeck, J. H. Thermodynamics of the Electron Acceptors in Heliobacterium modesticaldum: An Exemplar of an Early Homodimeric Type I Photosynthetic Reaction Center, Biochem. 55:2358-2370 (2016).
  • Ferlez B, Dong W, Siavashi R, Redding K, Hou HJ, Golbeck JH, van der Est A. The Effect of Bacteriochlorophyll g Oxidation on Energy and Electron Transfer in Reaction Centers from Heliobacterium modesticaldum. J Phys Chem B (2015).
  • McConnell, M.D., J. Sun, R. Siavashi, A.N. Webber, K.E. Redding, J.H. Golbeck, and A. van der Est. Species Dependent Alteration of Electron Transfer in Photosystem I. Biochim. Biophys. Acta Bioenergetics (2015).
  • Ort, D.R., S.S. Merchant, J. Alric, A. Barkan, R.E. Blankenship, R. Bock, R. Croce, M.R. Hanson, J.M. Hibberd, D.L. Lindstrom, S.P. Long, T.A. Moore, J. Moroney, K.K. Niyogi, M. Parry, P. Peralta-Yahya, R. Prince, K.E. Redding, M.H. Spalding, K. van Wijks, W.F.J. Vermaas, S. von Caemmerer, A.P.M. Weber, T. Yeates, J. Yuan, X. Zhu. Redesigning photosynthesis to sustainably meet global food and bioenergy demand. Proc. Natl. Acad. Sci. USA (2015).
  • Santabarbara, S., B. Bullock, F. Rappaport, K.E. Redding. Controlling electron transfer between the two cofactor chains of Photosystem I by the redox state of one of their components. Biophys. J (2015).
  • Yang, J.-H., Sarrou, I., Martin-Garcia, J.M., Zhang, S., Redding, K.E., Fromme, P. Purification and biochemical characterization of the ATP synthase from Heliobacterium modesticaldum. Protein Expression and Purification (2015).
  • Giera, W., S. Szewczyk, M.D. McConnell, J. Snellenburg, K.E. Redding, R. van Grondelle, K. Gibasiewicz. Excitation dynamics in Photosystem I from Chlamydomonas reinhardtii. Comparative studies of isolated complexes and whole cells. Biochem. Biophys. Acta Bioenergetics (2014).
  • K.E. Redding, I. Sarrou, F. Rappaport, S. Santabarbara, S. Lin, and K. Reifschneider. Modulation of the fluorescence yield in Heliobacterial cells by induction of charge recombination in the photosynthetic reaction center. Photosynthesis Research (2014).
  • Kashey, T., J.B. Cowgill, M.D. McConnell, M. Flores, K.E. Redding. Expression and characterization of cytochrome c553 from Heliobacterium modesticaldum. Photosynthesis Research (2014).
  • McConnell, M.D., D. Lowry, T.N. Rowan, K. van Dijk and K.E. Redding. Purification and photobiochemical profile of photosystem 1 from high-salt tolerant, oleaginous Chlorella (Trebouxiophycaea, Chlorophyta). Biochem Cell Biol (2014).
  • Reifschneider*, K.T., A. Kanygin, and K.E. Redding*. (2014). Expression of the [FeFe] hydrogenase in the chloroplast of Chlamydomonas reinhardtii. International Journal of Hydrogen Energy (2014).
  • Block A, Fristedt R, Rogers S, Kumar J, Barnes B, Barnes J, Elowsky CG, Wamboldt Y, Mackenzie SA, Redding K, Merchant SS, Basset GJ. Functional modeling identifies paralogous solanesyl-diphosphate synthases that assemble the side chain of plastoquinone-9 in plastids. Journal of Biological Chemistry (2013).
  • Chauvet, A., I. Sarrou, S. Lin, S. Romberger, J.H. Golbeck, S. Savikhin*, K.E. Redding. Temporal and Spectral Characterization of the Photosynthetic Reaction Center from Heliobacterium modesticaldum. Photosynthesis Research (2013).
  • Santabarbara, S., A.P. Casazza, K. Ali, C.K. Economou, T. Wannathong, F. Zito, K.E. Redding, F. Rappaport, and S. Purton. The Requirement for Carotenoids in the Assembly and Function of the Photosynthetic Complexes in Chlamydomonas reinhardtii. Plant Physiology (2013).
  • B.M. O’Neill, K.L. Mikkelson, N.M. Gutierrez, J.L. Cunningham, K.L. Wolff, S.J. Szyjka, C.B. Yohn, K.E. Redding and M.J. Mendez. An exogenous chloroplast genome for complex sequence manipulation in algae. Nucl. Acids Res (2012).
  • Chawla, M.D. Mai, A.K. Srivastava, K.V. Narashimulu, K.E. Redding, N. Vashi, D. Kumar, Adrie J.C. Steyn, and A. Singh. Mycobacterium tuberculosis WhiB4 maintains intracellular redox balance to promote recovery from non-replicating persistence and survival in macrophages. Mol. Microbiol (2012).
  • Mula, S., M.D. McConnell, A. Ching, N. Zhao, H.I. Gordon, G. Hastings, K.E. Redding, and A. van der Est. Introduction of a hydrogen bond between phylloquinone PhQ(A) and a threonine side-chain OH group in photosystem I. J Phys Chem B (2012).
  • S. Santabarbara, B. Bailleul, K.E. Redding, J. Barber, F. Rappaport, and A. Telfer. Kinetics of phyllosemiquinone oxidation in the Photosystem I reaction centre of Acaryochloris marina. Biochim. Biophys. Acta (2012).
  • Sarrou, I., Z. Khan, J. Cowgill, S. Lin, D. Brune, S. Romberger, J.H. Golbeck, K.E. Redding. Purification of the photosynthetic reaction center from Heliobacterium modesticaldum. Photosynthesis Research (2012).
  • B. Drop, B., M. Webber-Birungi, F. Fusetti, R. Kouril, K.E. Redding, E.J. Boekema and R. Croce. Photosystem I of Chlamydomonas reinhardtii is composed of nine Light-harvesting complexes (Lhca) located on one side of the core. J. Biol. Chem (2011).
  • M. Karamoko, S. Cline, K. Redding, N. Ruiz, and P. Hamel. Lumen Thiol Oxidoreductase1, a disulfide bond-forming catalyst, is required for the assembly of photosystem II in Arabidopsis. Plant Cell (2011).
  • M.D. McConnell, J.B. Cowgill, P.L. Baker, F. Rappaport and K.E. Redding. Double Reduction of Plastoquinone to Plastoquinol in Photosystem 1. Biochemistry (2011).
  • N. Srinivasan, S. Santabarbara, F. Rappaport, D. Carbonera, K. Redding, A. van der Est, J.H. Golbeck. Alteration of the H-Bond to the A(1A) Phylloquinone in Photosystem I: Influence on the Kinetics and Energetics of Electron Transfer. J. Phys. Chem. B (2011).
  • A.M. Collins, K.E Redding, R.E. Blankenship. Modulation of fluorescence in Heliobacterium modesticaldum cells. Photosynthesis Research (2010).
  • H. Jung, G. Gulis, S. Gupta, K. Redding, D.J. Gosztola, G.P. Wiederrecht, M.A. Stroscio, and M. Dutta. Optical and electrical measurement of energy transfer between nanocrystalline quantum dots and photosystem I. J. Phys. Chem. B (2010).
  • Marc G. Müller, Chavdar Slavov, Rajiv Luthra, Kevin E. Redding, Alfred R. Holzwarth. Independent initiation of primary electron transfer in the two branches of the Photosystem I reaction center. Proc. Natl. Acad. Sci. USA (2010).
  • S. Santabarbara, K. Reifschneider, A. Jasaitis, F. Gu, G. Agostini, D. Carbonera, F. Rappaport, K.E. Redding. Inter-quinone electron transfer in Photosystem I as evidenced by altering the hydrogen bond to the phylloquinone(s). J. Phys. Chem. B (2010).
  • Stefano Santabarbara, Kevin Redding, Fabrice Rappaport. Temperature dependence of the reduction of P700+ by tightly bound plastocyanin in vivo. Biochemistry (2009).
  • Galina Gulis, Kuppala V. Narasimhulu, Lisa N. Fox, Kevin E. Redding. Purification of His-tagged PS1 from Chlamydomonas reinhardtii. Photosynthesis Research (2008).
  • Kevin E. Redding and Douglas G. Cole. Chlamydomonas – a sexually active, light-harvesting, carbon-reducing, hydrogen-belching planimal. EMBO Reports (2008).
  • Stefano Santabarbara, Audrius Jasaitis, Martin Byrdin, Feifei Gu, Fabrice Rappaport, Kevin Redding. Additive Effect of Mutations Affecting the Rate of Phylloquinone Reoxidation and Directionality of Electron Transfer within Photosystem I. Photochemistry and Photobiology (2008).
  • Kevin Redding. Photosystem I. The Chlamydomonas Sourcebook: Volume 2 (2008).
  • G.S. Orf, C. Gisriel, K.E. Redding.  Evolution of photosynthetic reaction centers: insights from the structure of the heliobacterial reaction center.  Photosynth. Res. (2018).
  • T. Kashey, D.D. Luu, J.B. Cowgill, P.L. Baker, K.E. Redding.  Light-driven quinone reduction in heliobacterial membranes.  Photosynth. Res. (2018).
  • W. Giera, S. Szewczyk, M.D. McConnell, K.E. Redding, R. van Grondelle, K. Gibasiewicz.  Uphill energy transfer in photosystem I from Chlamydomonas reinhardtii.  Time-resolved fluorescence measurements at 77 K.  Photosynth. Res. (2018).
  • D. Sheehy, Y.-K. Lu, F. Osman, Z. Alattar, C. Flores, H. Sussman, S. Zaare, P. Baker, J. Touchman, K.E. Redding.  Genome-wide transcriptional response during the shift to N2-fixing conditions in Heliobacterium modesticaldum.  J. Proteomics Bioinformatics (2018).
  • P. Marco, M. Kozuleva, H. Eilenberg, Y. Mazor, P. Gimeson, A. Kanygin, K. Redding, I. Weiner, I. Yacoby.  Binding of ferredoxin to algal photosystem I involves a single binding site and is composed of two thermodynamically distinct events.  Biochim. Biophys. Acta (2018).
  • S.L. Badshah, J. Sun, S. Mula, M. Gorka, P. Baker, R. Luthra, S. Lin, A. van der Est, J.H. Golbeck, K.E. Redding.  Mutations in algal and cyanobacterial Photosystem I that independently affect the yield of initial charge separation in the two electron transfer cofactor branches.  Biochim. Biophys. Acta (2018).

Research Activity


Summer 2020
Course NumberCourse Title
BDE 792Research
Spring 2020
Course NumberCourse Title
BCH 462General Biochemistry
BIO 492Honors Directed Study
BIO 493Honors Thesis
MBB 495Undergraduate Research
BIO 495Undergraduate Research
BDE 792Research
BDE 799Dissertation
Fall 2019
Course NumberCourse Title
BCH 461General Biochemistry
BCH 462General Biochemistry
MIC 495Undergraduate Research
BIO 495Undergraduate Research
MBB 495Undergraduate Research
Spring 2019
Course NumberCourse Title
BCH 461General Biochemistry
BIO 495Undergraduate Research
BDE 792Research
BDE 799Dissertation
Fall 2018
Course NumberCourse Title
BCH 461General Biochemistry
MIC 495Undergraduate Research
BIO 495Undergraduate Research
Fall 2017
Course NumberCourse Title
BCH 461General Biochemistry
Spring 2017
Course NumberCourse Title
CHM 118Gen Chemistry for Majors II
Fall 2016
Course NumberCourse Title
BCH 461General Biochemistry
Spring 2016
Course NumberCourse Title
BCH 462General Biochemistry
Fall 2015
Course NumberCourse Title
BCH 461General Biochemistry