Mechanism of Methanol Inhibition of Photosynthetic Water Oxidation As Studied by Fourier Transform Infrared Difference and Time-Resolved Infrared Spectroscopies

Biochemistry
Haruna Yata, Takumi Noguchi

Abstract

Photosynthetic water oxidation is performed at the Mn4CaO5 cluster in photosystem II. In this study, we investigated the effect of methanol, an analogue of water, on the water oxidation reaction and its interaction site using Fourier transform infrared (FTIR) difference and time-resolved infrared (TRIR) spectroscopies. Flash-induced FTIR difference measurement of the S-state cycle showed that methanol decreases mainly the efficiency of the S3 → S0 transition. TRIR measurement further showed that methanol slowed the rates of the S2 → S3 and S3 → S0 transitions. FTIR difference spectra upon the S1 → S2 transition exhibited prominent methanol-induced changes in the amide I and II bands of the main chains, whereas little change was observed in the bands of carboxylate groups, histidine side chains, and a water network in the vicinity of the Mn4CaO5 cluster. Similar tendencies were also observed with ethanol and 2-propanol. The C-O stretching vibration of methanol was further identified in the S2-minus-S1 spectrum using 18O-labeled methanol. These results indicate that methanol and small alcohols are bound near the Mn4CaO5 cluster but with no direct interaction. They probably replace a water molecule in a water channel around the Mn...Continue Reading

References

Oct 16, 1992·Biochimica Et Biophysica Acta·R J Debus
Jun 1, 1970·Photochemistry and Photobiology·B KokM McGloin
Feb 16, 2006·Biochemistry·Hiroshi IshikitaErnst-Walter Knapp
Nov 10, 2006·Chemical Reviews·James P McEvoy, Gary W Brudvig
Oct 30, 2007·Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences·Takumi Noguchi
May 23, 2008·Coordination Chemistry Reviews·Richard J Debus
Sep 27, 2008·Photosynthesis Research·Birgit NöringJohannes Messinger
Jun 18, 2011·Biochemistry·Ivan RivaltaVictor S Batista
Feb 6, 2013·Biochimica Et Biophysica Acta·Nicholas Cox, Johannes Messinger
Oct 11, 2013·Journal of the American Chemical Society·Koji OgataShinichiro Nakamura
Jun 4, 2014·Proceedings of the National Academy of Sciences of the United States of America·Daniele NarziLeonardo Guidoni

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Citations

Aug 30, 2020·Biochimica Et Biophysica Acta. Bioenergetics·Ipsita GhoshGary W Brudvig
Sep 27, 2020·Biochimica Et Biophysica Acta. Bioenergetics·Casper de LichtenbergJohannes Messinger
Feb 2, 2019·Biochemistry·Ipsita GhoshGary W Brudvig

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