Most of the carbohydrate moiety of invertase and fructosyltransferase (FTF) from F. oxysporum IMI 172464 was removed by peptide-N-glycosidase F. The molecular weights of native invertase and FTF were 260 kDa and 210 kDa respectively. Deglycosylation lowered the molecular sizes by 42% and 23%, respectively. The K-m values for sucrose remained unchanged by deglycosylation. However the stability of both enzymes at their optimum pH (4.0 for invertase, 5.0 for FTF) and optimum temperature (45 degrees C for invertase, 35 degrees C for FTF) was decreased : their sensitivity to protease digestion was increased by 36% and 41%, respectively. The synthetic specificity of deglycosylated FTF remained unchanged. The carbohydrate moiety of invertase and FTF contributes to the stability of the enzymes but is not essential in their catalytic function and plays no part in determining their specificity.