Affordable Access

Trapping kinetics in mutants of the photosynthetic purple bacterium Rhodobacter sphaeroides: influence of the charge separation rate and consequences for the rate-limiting step in the light-harvesting process.

Authors
  • Beekman, L M
  • van Mourik, F
  • Jones, M R
  • Visser, H M
  • Hunter, C N
  • van Grondelle, R
Type
Published Article
Journal
Biochemistry
Publication Date
Mar 22, 1994
Volume
33
Issue
11
Pages
3143–3147
Identifiers
PMID: 8136347
Source
Medline
License
Unknown

Abstract

The primary light-harvesting processes, energy transfer in the light-harvesting antenna, and trapping of the excited states by reaction centers were studied in several mutant strains of the photosynthetic purple bacterium Rhodobacter sphaeroides. The mutants had reaction centers in which the rates of electron transfer were modified by site-directed mutations at the M210 position. Low-intensity pump-probe laser spectroscopy was used to monitor the absorbance transients in the Qy region of the antenna pigments, and it was found that despite a wide variation in charge separation rates within the RC, produced by the alterations at Tyr M210, there was relatively little corresponding variation in the overall trapping rate. These effects of the mutations on the trapping kinetics demonstrate that the rate-limiting step of the overall light-harvesting process is the transfer of the excitations from the antenna to the reaction center.

Report this publication

Statistics

Seen <100 times