LINEAR AND CIRCULAR DICHROISM OF MEMBRANES FROM RHODOPSEUDOMONAS CAPSULATA
Absorption, linear dichroism and circular dichroism spectra of Rhodopseudomonas capsulate (wild-type - St. Louis strain, mutant Y5 and mutant A1a{sup +}) are particularly sensitive to the nature of the light-harvesting bacteriochlorophyll-carotenoid-protein complexes. Evidence for exciton-type interactions is seen near 855 nm in the membranes from the wild-type and from mutant Y5, as well as in an isolated B800+850 light-harvesting complex from mutant Y5. The strong circular dichroism that reflects these interactions is attenuated more than 10-fold in membranes from the A1a+ mutant, which lacks both B800+850 and colored carotenoids and contains only the B875 light-harvesting complex. These results lead to the conclusion that these two light-harvesting complexes have significantly different chromophore arrangements or local environments.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Chemical Sciences Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 1090452
- Report Number(s):
- LBL-11757
- Journal Information:
- Biochimica et Biophysica Acta, Journal Name: Biochimica et Biophysica Acta
- Country of Publication:
- United States
- Language:
- English
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