Agricultural and Biological Chemistry · 1972 · 19 citations · 1 references
Life SciencesBiochemistryPlant BiologyCarbohydrate BiochemistryEnzymologyPlant BiochemistryCarbohydrate MetabolismEnzyme CharacterizationEnzyme IsolationEnzyme KineticsEnzyme PurificationPlant EnzymesAmmonium Sulfate FractionationEnzyme Purification KineticsFruit Enzyme ActivityFruit EnzymologyProtein Separation TechniquesSilver Nitrate TreatmentSucrose Metabolism EnzymesSucrose Purification
At least two distinct sucrose-splitting enzymes such as β-fructofuranosidase (β-FFase) E and L have been demonstrated in the tomato cell walls. Both β-FFase were purified by means of ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50 and the gel filtration on Sephadex G-200 column. The highly purified β-FFase E (early fraction in the DEAE-Sephadex chromatography) and L (late fraction) thus obtained, contained carbohydrate at about 5.3 and 9.1% respectively. Both enzymes had the same optimal pHs of 4.5 and 5.1 for sucrose and raffinose, respectively, and were completely inactivated by the incubation at 55°C for 5 min. Activation energies were 7,370 and 17, 300 cal/mole for, β-FFase E and L, respectively. For both enzymes, Km values for raffinose were higher than those for sucrose. The activities of both enzymes were strongly inhibited with p-chloromercuribenzoate and silver nitrate (1×10−4 m). β-FFase E but L was activated by potassium ferrocyanide (1×10−4 m).
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