title: Low-temperature (77 K) phosphorescence of triplet chlorophyll in isolated reaction centers of photosystem II.
abstract: Phosphorescence characterized by the main emission band at 952 ± 1 nm (1.30 eV), the lifetime of 1.5 ± 0.1 ms and the quantum yield nearly equal to that for monomeric chlorophyll a in aqueous detergent dispersions, has been detected in isolated reaction centers (RCs) of spinach photosystem II at 77 K. The excitation spectrum shows maxima corresponding to absorption bands of chlorophyll a, pheophytin a, and β-carotene. The phosphorescence intensity strongly depends upon the redox state of RCs. The data suggest that the phosphorescence signal originates from the chlorophyll triplet state populated via charge recombination in the radical pair [Formula: see text].
authors.affiliation: A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr., 33, Moscow, 119071, Russian Federation.
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Neverov
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Krasnovsky
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Zabelin
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Shuvalov
authors.forename: Anatoly Ya
authors.initials: AY
authors.lastname: Shkuropatov
mesh_terms: D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000378:metabolism; D000077194:Chlorophyll A; D003080:Cold Temperature; D008163:Luminescent Measurements; D010674:Pheophytins / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018724:Spinacia oleracea / Q000378:metabolism*; D019207:beta Carotene / Q000378:metabolism
chemical_list: D010674:Pheophytins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D019207:beta Carotene; D002734:Chlorophyll; C085815:chlorophyll a'; C061694:pheophytin a; D000077194:Chlorophyll A