Abstract
The activity and half-life of pectate lyase (PL) from Bacillus megaterium were nine- and 60-fold, respectively, higher at 90 degrees C in the presence of hydroxyapatite nanoparticles (NP-PLs) than in the presence of 1 mM CaCl2. Thermodynamic analysis of the nanoparticle-induced stability revealed an enhanced entropy-enthalpy compensation by the NP-PLs since a reciprocal linearity of the enthalpy-entropy change to 90 degrees C was observed. Without nanoparticles, the linearity range was 70 degrees C. Such compensation reflected the maintenance of the native structure of proteins. The remarkable enhancement of activity and stability of the NP-PL system at high temperatures may be utilized commercially e.g. in the food industry or the processing of natural fibers that may require a thermotolerant enzyme. (C) 2012 Elsevier Ltd. All rights reserved.