Abstract
Phenoloxidase was purified from pupae of the housefly, Musca domestica L. The purification procedures included ammonium sulfate precipitation, affinity chromatography and Sephadex G-200 gel filtration. The final preparations appear to be homogeneous based on results obtained from polyacrylamide gel electrophoresis. The molecular weight of phenoloxidase was estimated to be 330, 000, as determined by gel filtration. The kinetic properties of phenoloxidase were studied using six catecholamines as substrates. The preferred order of substrates for phenoloxidase was found to be N-β-alanyldopamine>dopamine>N-acetyldopamine>norepinephrine>epinephrine>DOPA.
