Properties of Granule-bound Starch Synthetase from Various Higher Plants

Abstract

Some properties of granule-bound starch synthetase from leaves and storage tissues of various higher plants were studied. Their pH optima were found in the range of 8.0-9.0 in most enzyme preparations from the plants. Stimulative effect of K⁺ on the activity of granule-bound starch synthetase was observed in most enzyme preparations from leaves of the plants, but no effect was observed in most enzyme preparations from storage tissues of the plants. Stimulative effect of Mg⁺⁺, Ca⁺⁺ and Mn⁺⁺ on the activity of granules-bound starch syathetase was observed in most enzyme preparations. ADP-glucose was exclusively utilized as substrate by the enzymes from the leaves of the plants, whereas the enzymes from the storage tissues of several plants utilized both ADP-glucose and UDP-glucose as substrate.