ACTION OF CARICA-PAPAYA LATEX ON CELL-WALL GLYCOSIDASES FROM LACTUCA-SATIVA PITH

The various glycosidase activities from Carica papaya latex and pith c ell walls from Lactuca sativa were measured by using pNP-glycoside sub strates. A decrease of enzymic activities was obtained by incubation o f isolated cell walls with C. papaya latex. Thus parietal activities d ecreased by the following amounts: N-acetyl-beta-D-glucosaminidase by 83%, beta-D-glucosidase by 45%, beta-D-fucosidase by 53% and alpha-D-g alactosidase by 25% after an incubation of 24 hr. These results indica te that C. papaya latex has no stimulatory effect on the cell wall enz ymes tested. Addition of cysteine protease inhibitor to medium culture causes a smaller decrease of parietal glycosidic activities. Carica p apaya latex proteases and glycosidases are, therefore, responsible for the decrease of cell wall glycosidic activities after action of this latex. A comparison with the increase of glycosidic activities of Cand ida albicans cultured in a medium supplemented with latex indicates a possible stimulation of glycoprotein synthesis by Golgi apparatus for this enzymic activation.