An ESEEM study of the oxidized electron donor of plant photosystem II: Evidence that D is a neutral tyrosine radical

R. G. Evelo, A. J. Hoff, S. A. Dikanov, A. M. Tyryshkin

Research output: Contribution to journalArticlepeer-review

Abstract

Electron spin-echo envelope modulation (ESEEM) has been performed on the tyrosyl radical D{A figure is presented} in photosystem II of plants and algae. This radical was investigated in PS II-enriched subchloroplast particles, and in perdeuterated and 15N-substituted Chlorella vulgaris algae. From the ESEEM analysis in the time and frequency domain, two proton hyperfine interactions were determined. One of these protons has hyperfine parameters aiso=27.2 MHz, T11=-3.1 MHz and T22/T11=0.5. The second proton, which is easily exchangeable by deuterium, has parameters aiso=±1.6 MHz, T11=∓8.4 MHz and T22/T11=1. The hyperfine parameters of the first proton are characteristic of a β-methylene proton, whereas those of the second indicate that it is a proton hydrogen bonded to the tyrosyl oxygen. We conclude that the oxidized tyrosyl donor is a neutral hydrogen-bonded radical.

Original languageEnglish (US)
Pages (from-to)479-484
Number of pages6
JournalChemical Physics Letters
Volume161
Issue number6
DOIs
StatePublished - Sep 29 1989
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'An ESEEM study of the oxidized electron donor of plant photosystem II: Evidence that D is a neutral tyrosine radical'. Together they form a unique fingerprint.

Cite this