[Effect of temperature on the phototransformation of purple sulfur bacteria bacteriochlorophylls and isolated chromatophores].
Photobleaching of P890 was shown to be independent of temperature within the range of +20 to -160 degrees C in purple sulphur bacteria and isolated chromatophores under oxidative conditions; therefore changes in the absorption at 890 nm are due to the primary photoact. No changes were detected in the absorption at 850 nm upon a slight decrease of temperature, which suggested the absorption at 850 nm upon a slight decrease of temperature, which suggested the conformation nature of these changes. The effect of temperature, which suggested the conformation nature of these changes. The effect of temperature on the photoinduced changes of absorption under reductive conditions seems to be due to the electron transport and the accompanying processes being blocked. The effect of temperature on the kinetics of P890+ reduction in the darkness under conditions when the cytochromes are preliminarily oxidized is determined by the participation of the secondary electron acceptors in this process. A decrease in temperature leads to blocking the transport of electrons from the primary acceptor to the secondary acceptors, which is expressed by a gradual disappearance of a slow component in the kinetics of p890+ reduction in the disappearance of a slow component in the kinetics of P890+ reduction in the darkness and by the intensification of a fast component resulting from the darkness and by the intensification of a fast component resulting from the interaction between the primary acceptor and P890+. Methodical aspects of absorption differential spectrophotometry of photosynthesizing organisms at low temperatures are discussed.
D001419:Bacteria / Q000201:enzymology / Q000378:metabolism*; D020130:Bacterial Chromatophores / Q000378:metabolism*; D001429:Bacteriochlorophylls / Q000378:metabolism; D002734:Chlorophyll / Q000031:analogs & derivatives*; D002844:Chromatium / Q000201:enzymology / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D003624:Darkness; D004579:Electron Transport; D008027:Light; D013057:Spectrum Analysis; D013696:Temperature
D001429:Bacteriochlorophylls; D003580:Cytochromes; D002734:Chlorophyll
Temperaturnaia zavisimost' fotoprevrashcheniia bakteriokhlorofillov purpurnykh serobakteriĭ i izolirovannykh khromatoforov