Kinetics of Denaturation and Effects of Surfactants and Polyethylene Glycol on Soybean Esterase (Glycine max L) Stability

Abstract

The objective of this work was to evaluate the kinetics and thermodynamics parameters and the effects of anionic, cationic and nonionic surfactants and polyethylene glycol on the activity and stability of a crude esterase extracted from soybeans (Glycine max L.). The activation energy for thermal inactivation was calculated from the Arrhenius plot was found to be 59.4 kJ mol −1 and the ΔH* 56.82 kJ mol −1 at 40 °C, which was the optimum temperature for enzyme activity. The ΔS* and ΔG* of the enzyme were found to be 61.67 kJ mol −1 and 15.50 J mol −1 K −1 , respectively, at the optimum temperature. The activity was only enhanced by the cationic surfactants cetyltrimethylammonium bromide and tetradecylmethylammonium bromide at a concentration of 3.0 mM. The anionic surfactant showed a positive effect on enzyme activity at the concentrations of 1.5 and 3.0 mM. Aqueous PEG (polyethylene glycols) solutions activated the esterase, and maximum activation (170 %) occurred with the addition of 6 kDa PEG. PEG with molecular weights of 0.4 and 10 kDa enhanced enzyme stability at 40 °C.

Partial purification and biochemical characterization of an alkaline esterase from Sorghum bicolor

“…Esterases or carboxylesterases (carboxylic-ester hydrolases; EC 3.1.1.1) belong to the international enzymatic class of hydrolases and comprise a group of "lipolytic enzymes" able to hydrolyze hydrophobic short and long chain carboxylic acid esters (Singh, Gupta, Goswami, & Gupta, 2006;Barros, Celligoi, & Macedo, 2016). Due to their ample availability esterases are of interest for application in industrial processes.…”