Superoxide Dismutase in the Anaerobic Flagellates, Tritrichomonas foetus and Monocercomonas sp

Abstract

Abstract Superoxide dismutase activity is present in the facultative anaerobic flagellates, Tritrichomonas foetus and Monocercomonas sp. The enzyme has a similar specific activity in these organisms, as it has in Escherichia coli, Tetrahymena pyriformis, and rat liver. About five-sixths of the activity of T. foetus is in the nonsedimentable portion of the cytoplasm. The rest is connected with a subcellular organelle, the hydrogenosome, and exhibits structure-bound latency which can be abolished by freezing and thawing or with the detergent Triton X-100. The enzymes from both locations differ in their electrophoretic mobility on polyacrylamide gels. They are similar in their molecular weight (38,000) and in their sensitivity to heat or organic solvents. Neither of them is inhibited by cyanide.