Study of thermal stability of two acid phosphatases from breadfruit (Artocarpus communis) seeds: kinetic and thermodynamic analysis

Abstract

The thermal stability of acid phosphatases ACP1 and ACP2 from breadfruit (Artocarpus communis) seeds was investigated by studying the effect of heat treatment over a range of 55 to 75 °C. Thermal inactivation of each enzyme, evaluated by loss in activity, was apparently followed by first-order kinetics with k-values comprised between 0.0139 ± 0.0005–0.0620 ± 0.0001 and 0.0117 ± 0.0002–0.0362 ± 0.0004 min^-1 for ACP1 and ACP2, respectively. D and k-values decreased and increased, respectively, with increasing temperature, indicating faster inactivation of ACP1 and ACP2 at higher temperatures. Ea and Z-values were estimated to 69.19 ± 2.71 kJ/mol and 31.55 ± 1.05 °C for ACP1, 52.25 ± 1.94 kJ/mol and 41.84 ± 2.06 °C for ACP2. Thermodynamic parameters were also calculated. All the results suggest that both acid phosphatases are relatively resistant to long heat treatments up to 60°C.