Lifetime of fluorescence from light-harvesting chlorophyll a/b proteins. Excitation intensity dependence

Academic Article


  • The fluorescence from a purified, aggregate form of the light-harvesting chlorophyll a/b protein has a lifetime of 1.2 +/- 0.5 ns at low excitation intensity, but the lifetime decreases significantly when the intensity of the 20-ps, 530-nm excitation pulse is increased above about 10(16) photons/cm2. A solubilized, monomeric form of the protein, on the other hand, has a fluorescence lifetime of 3.1 +/- 0.3 ns independent of excitation intensity from 10(14)-10(18) photons/cm2/pulse. We interpret the lifetime shortening in the aggregates and the lack of shortening in monomers in terms of exciton annihilation, facilitated in the aggregate by the larger population of interacting chlorophylls. © 1981, The Biophysical Society. All rights reserved.
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    Author List

  • Nordlund TM; Knox WH
  • Start Page

  • 193
  • End Page

  • 201
  • Volume

  • 36
  • Issue

  • 1