Extraction and characterization of pectin methylesterase from Alyanak apricot (Prunus armeniaca L).

This study was carried out to determine some of the biochemical properties of pectin methylesterase (PME) from Alyanak apricot which is an important variety grown in Malatya region of Turkey. The enzyme had high activity in a pH range of 7.0-8.0 with the maximal activity occurring at pH 7.5. However, the enzyme activity at high and low pH values was very low. The optimum temperature for maximal PME activity was found to be 60 °C. The activity of PME has been enhanced by NaCl, particularly at 0.15 M. Km and Vmax values for Alyanak apricot PME using apple pectin as substrate were found to be 1.69 mg/mL (r(2) = 0.992) and 3.41 units/mL, respectively. The enzyme was stable at 30-45 °C/10 min whereas it lost nearly all of its activity at 80 °C/10 min. Ea and Z values were found to be 206.1 kJ/mol (r(2) = 0.993) and 10.62 °C (r(2) = 0.992), respectively.