Measurement of the Cyanophycin Granule Polypeptide Contained in the Blue-Green Alga Anabaena cylindrica

An assay was developed to determine the amount of cyanophycin granules in blue-green algae. The amount of this polypeptide in cells of Anabaena cylindrica was measured as a function of culture age and was compared with changes in other proteinaceous cellular components. The data presented support the notion that the cyanophycin granule is a cellular nitrogen reserve.