Extracellular and Intracellular Phenoloxidase Activity during Growth and Development in Schizophyllum

Abstract
Phenoloxidase activity was studied during different phases of the fruiting response in S. commune. Refined methods of growth were utilized which allowed the patterns of extracellular and intracellular phenoloxidase activity to be studied separately. Extractable intracellular protein and excreted protein levels were measured and compared with phenoloxidase activity. Specific enzyme activity observed during the fruiting cycle was found to be relatively independent of measured protein levels and largely reflected extracellular activity. The results of mixing experiments suggested that the decline in phenoloxidase activity in mature fruiting colonies may have been due to the presence of inhibitory substances produced during development.