REDUCED NICOTINAMIDE–ADENINE DINUCLEOTIDE OXIDATION IN ESCHERICHIA COLI PARTICLES: III. CELLULAR LOCATION OF MENADIONE REDUCTASE AND ATPase ACTIVITIES

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Abstract
Sonic extracts of Escherichia coli were fractionated to membrane-wall, small-particle, and soluble fractions. Menadione reductase and ATPase activities were found in all fractions. The menadione reductase activity of the soluble fraction was resolved into three enzymes. Enzymes with properties similar to two of these could be released from the particulate fraction by treatment with sodium dodecyl sulfate or chelating agents. The major ATPase of the particulate fractions was solubilized by detergent. Osmotic shock experiments suggested that it was located outside the plasma membrane in the intact cell. It differed from the ATPase of the soluble fraction. An enzyme resembling the latter ATPase was solubilized from the small-particle fraction by chelating agents and could be rebound in the presence of magnesium ions. Solubilized menadione reductase was not rebound to particulate fractions under these conditions.