Factors in the Determination of the Intracellular Localization of Enzymes

Abstract

The effect of pH value of the sucrose blending medium in fractionation of cell components was shown by the distribution of some constituents between chloroplasts and soln. Catalase activity was all associated with the chloroplastic material at pH 5 and was mostly in the soluble fraction at pH 3.3 or 5.6. Essentially complete retention of chloroplastin by the plastids was found at pH 3-4. Results emphasize that the constituents comprising a cellular component will not act as a single entity but will exhibit individual responses to factors involved in liberation of cell contents.