The isolation and properties of a proteolytic enzyme, cathepsin D, from bovine spleen

Abstract

COLOROPLASTS 501 to the conclusion that the factor can catalyse the reduction of soluble material in the leaf extracts. Further work is necessary to trace the paths of hydrogen transport after the reduction of the factor by the illuminated chloroplast and to deter- mine the nature of the group concerned in the oxidation-reduction cycle. SUMMARY 1. A protein factor from leaves, previously shown to be active in catalysing the reduction of methaemoglobin and metmyoglobin by illuminated chloroplasts, has been purified by fractionation with ammonium sulphate followed by electro- phoretic separation of the active material on paper.