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Deconvolution Analysis of Photoacoustic Waves of Electron Transfer in Photosystem I of menG Null Mutant of Synechocystis sp. PCC 6803

  • Xuejing Hou
  • Lien-Yang Chou
  • Harvey J. M. HouEmail author
Conference paper
Part of the Advanced Topics in Science and Technology in China book series (ATSTC)

Abstract

Inactivating the menG gene causes 2-phytyl-1,4-naphthoquinone (Q) to be presented as a quinone acceptor in PSI of Synechocystis sp. PCC 6803. The electron transfer from Q to FX is slowed to 600 ns in the menG null mutant [Sakuragi Y, B Zybailov G Shen, AD Jones, PR Chitnis, A van der Est, R Bittl, S Zech, D Stehlik, JH Golbeck, and DA Bryant. (2002) Biochemistry 41: 394–405]. Despite of the alternation of kinetics, the thermodynamics of electron transfer in the mutant is not known. In this work, we conducted deconvolution analysis on photoacoustic waves of the menG null mutants and the wild type strains of Synechocystis sp. PCC 6803 obtained by pulsed photoacoustics on the microsceond time scale. The fit by convolution of menG photoacoustic waves revealed a large volume contraction (−28 ± 2 Å3) for the P700* → Q step and a positive volume change (+5 ± 2 Å3) for the Q → FA/B step. The enthalpy changes were −0.7 ± 0.2 eV for the P700* → Q step and +0.5 ± 0.2 eV for the Q → FA/B step, respectively. Taking the free energy of −0.7 eV and −0.1 eV for these steps, the data presented here shows that the Q to FA/B electron transfer step in the menG null mutant is entropy driven.

Keywords

Enthalpy Entropy Volume change Photoacoustics Electron transfer Photosystem I menG 

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References

  1. Delosme R, D Beal, P Joliot (1994) Photoacoustic Detection of Flash-Induced Charge Separation in Photosynthetic Systems. Spectral Dependence of the Quantum Yield. Biochim. Biophys. Acta. 1185: 56–64Google Scholar
  2. Edens GJ, MR Gunner, Q Xu, D Mauzerall (2000). The Enthalpy and Entropy of Reaction for Formation of P+QA from Excited Reaction Centers of Rhodobacter Sphaeroides. J. Am. Chem. Soc. 122: 1479–1485CrossRefGoogle Scholar
  3. Feitelson J D Mauzerall (2002) Enthalpy and Electrostriction in the Electron-Transfer Reaction between Triplet Zinc Uroporphyrin and Ferricyanide. J. Phys. Chem. B. 106: 9674–9678CrossRefGoogle Scholar
  4. Hou HJM, D Mauzerall (2006) The A-FX to FA/B Step in Synechocystis 6803 Photosystem I is Entropy Driven. J. Am. Chem. Soc. 128: 1580–1586PubMedCrossRefGoogle Scholar
  5. Hou HJM, G Shen, VA Boichenko, JH Golbeck, D Mauzerall (2009) Thermodynamics of Charge Separation of Photosystem I in the MenA and MenB Null Mutants of Synechocystis sp. PCC 6803 Determined by Pulsed Photoacoustics. Biochemistry 48: 1829–1837PubMedCrossRefGoogle Scholar
  6. Hou JM, VA Boichenko, BA Diner, D Mauzerall (2001a) Volume Change, Enthalpy, and Entropy of Electron Transfer Reactions in Manganese-Depleted Photosystem II Core Complexes. Biochemistry 40: 7117–7125PubMedCrossRefGoogle Scholar
  7. Hou JM, VA Boichenko, YC Wang, PR Chitnis, D Mauzerall (2001b) A Pulsed Photoacoustic Study of Electron Transfer in Photosystem I Reveals a Similarity to Bacterial Reaction Centers in Both Volume Change and Entropy. Biochemistry 40: 7109–7116PubMedCrossRefGoogle Scholar
  8. Losi A, I Yruela, M Reus, AR Holzwarth, SE Braslavsky (2003) Structural Changes upon Excitation of D1-D2-Cyt b559 Photosystem II Reaction Centers Depend on the β-carotene Content. Photochem. Photobiol. Sci. 2: 722–729PubMedCrossRefGoogle Scholar
  9. Rizzi AC, M van Gastel, PA Liddell, RE Palacios, GF Moore, G Kodis, AL Moore, TA Moore, D Gust, SE Braslavsky (2008) Entropic Changes Control the Charge Separation Process in Triads Mimicking Photosynthetic Charge Separation. J. Phys. Chem. A. 112:4215–4223PubMedCrossRefGoogle Scholar
  10. Sakuragi Y, B Zybailov, G Shen, AD Jones, PR Chitnis, A van der Est, R Bittl, S Zech, D Stehlik, JH Golbeck, DA Bryant (2002) Insertional Inactivation of the MenG Gene, Encoding 2-phytyl-1,4-naphthoquinone Methyltransferase of Synechocystis sp. PCC 6803, Results in the Incorporation of 2-phytyl-1,4-naphthoquinone into the A1 Site and Alteration of the Equilibrium Constant between A1 and FX in Photosystem I. Biochemistry 41: 394–405PubMedCrossRefGoogle Scholar
  11. Small JR, LJ Libertini, EW Small (1992) Analysis of Photoacoustic Waveforms Using the Nonlinear Least Squares Method. Biophys. Chem. 42: 29–48PubMedCrossRefGoogle Scholar

Copyright information

© Zhejiang University Press, Hangzhou and Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Xuejing Hou
    • 1
  • Lien-Yang Chou
    • 1
  • Harvey J. M. Hou
    • 1
    Email author
  1. 1.Department of Chemistry and BiochemistryUniversity of Massachusetts DartmouthNorth DartmouthUSA

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