Purification and characterization of pectin methylesterase from acerola (Malpighia glabra L.)

The enzyme pectinmethylesterase (PME) from acerola was extracted and purified by gel anion-exchange chromatography (Q Sepharose) and filtration on Sephadex G-100. The results showed two different PME isoforms (PME1 and PME2), with molecular masses of 25.10 and 5.20 kDa, respectively. PME1 specific activity increased by 9.63% after 60 min incubation at 98 °C, while PME2 retained 66% of its specific activity under the same conditions. The K(m) values of PME1, PME2 and concentrated PME were 0.94, 0.08 and 0.08 mg mL(-1), respectively. The V(max) value of PME1, PME2 and concentrated were 204.08, 2, 158.73 and 2.92 μmol min(-1) mg(-1) protein, respectively.