Improvement of thermostability and activity of pectate lyase in the presence of hydroxyapatite nanoparticles

► The activity of PL is enhanced at high temperature in presence of HAp-NP. ► NP-PL retained its activity for 4 hrs at 90°C. ► NP-PL activity was found to increase gradually with time at 90°C. ► NP-PL had enhanced entropy enthalpy compensation at high temperatures. ► NP-PL can be potentially used for the processing of food and natural fibers. The activity and half-life of pectate lyase (PL) from Bacillus megaterium were nine- and 60-fold, respectively, higher at 90°C in the presence of hydroxyapatite nanoparticles (NP-PLs) than in the presence of 1mM 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°C was observed. Without nanoparticles, the linearity range was 70°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.