Investigating the thermodynamic and kinetics properties of acid phosphatase extracted and purified from seedlings of Chenopodium murale

Abstract

Herein acid phosphatase isoenzyme was extracted from the C. murale seedlings. The purification was accomplished by chromatographic techniques and passing through DEAE-cellulose and Sephadex G-100 column. The specific activity of acid phosphatase 5.75 U/mg of protein was obtained with 66 purification fold 15.8% yield and molecular mass was 29 kDa with very faint bands corresponding to 18 kDa and 14 kDa. The maximal activity at pH 5.0 and 50 °C best illustrated by first order kinetics. When temperature was raised (55 °C to 75 °C), the deactivation rate constant was increased from 0.001 to 0.014 min^-1, while half-life was decreased from 693 to 49 min^-1. The results of activity collected at different temperature were then used to estimate, activation energy of hydrolysis reaction (Ea = 47.59 kJmol^-1). A high Z-value (18.86 °C min^-1) was obtained indicating a less sensitivity towards temperatures. The residual activity examinations were carried out from 55 °C to 75 °C and assessing the Deactivation Energy (Ed 116.39 kJmol^-1), Enthalpy change (ΔH° 113.55kJmol^-1), Entropy change (ΔS° 110.33kJmol^-1) and change in Gibbs free energy (ΔG° 10.02 kJmol^-1). Taken together, thermodynamic parameters confirm the high stability of enzyme and show potential commercial applicability.

Keywords: Acid phosphatase; Chenopodium murale seedlings; Kinetics and thermodynamics studies.