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AN ABSORPTION BAND NEAR 800 mμ ASSOCIATED WITH P870 IN PHOTOSYNTHETIC BACTERIA *
Author(s) -
Clayton Roderick K.,
Sistrom William R.
Publication year - 1966
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1966.tb05812.x
Subject(s) - bacteriochlorophyll , photosynthetic reaction centre , photochemistry , photosynthesis , purple bacteria , pigment , chemistry , population , fluorescence , action spectrum , absorption (acoustics) , botany , biology , physics , optics , demography , organic chemistry , sociology
— Purple photosynthetic bacteria contain a component, absorbing near 805 mμ, distinct from the major light harvesting bacteriochlorophyll component. The minor component, designated P800, resembles P870 in that it resists oxidative treatments that destroy the light harvesting bacteriochlorophyll. Light induces a reversible blue‐shift of P800 together with the reversible bleaching of P870. The ratio of P800 to P870 in Rhodopseudomonas spheroides is constant. Both pigments are absent in phenotypes that cannot grow photosynthetically; they reappear together in revertants to photosynthetic competence. Action spectra for light‐induced bleaching of P870 and for bacteriochlorophyll fluorescence show that P800 transfers energy more efficiently to P870 than to the bulk bacteriochlorophyll. It is concluded provisionally that P800 is a specialized bacteriochlorophyll molecule in close proximity to the reaction center component P870.