Proteolytic activity of lectins from the nitrogen-fixing bacterium Bacillus polymyxa

Two lectins (LI and LII) stripped from the surface of Bacillus polymyxa 146 0 cells were found to possess proteolytic activity. which was associated wi th their hemagglutinating activity. The inhibition of the hemagglutinating activity of lectins by specific carbohydrate haptens changed their enzyme a ctivities. The inhibition of hemagglutinating activity by glucuronic acid o r fructose 1,6-diphosphate decreased the proteolytic activities of both lec tins, whereas the blocking of this activity with D-glucosamine or D-galacto samine increased the proteolytic activity of LII. The molecules of the B. p olymyxa lectins are suggested to contain two active centers responsible for hemagglutinating and proteolytic activities.