PRODUCTION OF STABLE ISOTOPE-KLABELED CYTOCHROME C3 DERIVED FROM SULFATE REDUCING BACTERIA

PURPOSE:To provide a method for production of stable isotope-labeled cytochrome C3 derived from sulfate reducing bacteria and useful for a biological device and a material for studying biological device. CONSTITUTION:This method for production of stable isotope-labeled cytochrome C3 is carried out by culturing and growing sulfate reducing bacteria in a chemosynthetic medium containing a nitrogen source composed of plural amino acids in which only a specified amino acid is labeled with a stable isotope under an anaerobic condition and synthesizing cytochrome C3 in the sulfate reducing bacteria, or by culturing and growing sulfate reducing bacteria in a chemosynthetic medium containing a nitrogen source composed of only ammonium chloride which is labeled with a stable isotope under an anaerobic condition and synthesizing cytochrome C3 in the sulfate reducing bacteria. A part of the amino acids constituting the obtained cytochrome C3 or the whole cytochrome C3 can be labeled thereby with the stable isotope with a high level. Especially, this is the first method which can label the whole cytochrome C3 by NH4Cl. In addition, this method can reduce the amount of labeled amino acids to 1/10 in comparison with the conventional method and the cost of expensive stable isotope, therefore, can remarkably be reduced.