Particulate fractions making cellulose from UDP glucose (glucose-14C) were obtained by chromatography of oat seedling cell wall-free homogenates on Sepharose 4B. All particle fractions obtained formed varying proportions of glucolipid and polysaccharide. The optimal pH for cellulose synthesis was about 8. Activity was higher in Tris buffer than in phosphate buffer. Dithiothreitol enhanced the cellulose synthetase activity. Glycerol (0.37M) in the incubation medium had no effect on either glycolipid or polysaccharide synthesis. Treatment of particles with phospholipase A (EC 3.1.1.4) inhibited the enzyme systems in some fractions obtained by Sepharose chromatography and increased them in others. Non-ionic and anionic detergents greatly inhibited the enzymes. Addition of lecithin to detergent-treated particles partially restored enzyme activity. Solubilization of the enzyme with retention of activity was not obtained.
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