[Effect of deuteration on the kinetics of photoinduced electron transport in the reaction centers of purple bacteria].

Substitution of H2O for D2O in the preparations of reaction centres from chromatophore membranes of photosynthesizing bacteria Rhodopseudomonas sphaeroides, 1760-1 results in a decrease of the efficiency of direct electron transfer from photoreduced primary quinone X1- to the secondary ones and in rising possibilities for reversible reaction X1- with photooxidized bacteriochlorophyll. The value of isotope effect which does not usually exceed 1.2 depends on temperature; it is not found in the temperature range below -60 degrees divided by -80 degrees C.