Nanotechnology Enabled Enhancement of Enzyme Activity and Thermostability: Study on Impaired Pectate Lyase from Attenuated Macrophomina phaseolina in Presence of Hydroxyapatite Nanoparticle

In this paper we show that hydroxyapatite nanoparticles (NP) can not only act as a chaperon (by imparting thermostability) but can serve as a synthetic enhancer of activity of an isolated extracellular pectate lyase (APL) with low native state activity. The purified enzyme (an attenuated strain of Macrophomina phaseolina) showed feeble activity at 50 degrees C and pH 5.6. However, on addition of 10.5 mu g/ml of hydroxyapatite nanoparticles (NP), APL activity increased 27.7 fold with a 51 fold increase in half-life at a temperature of 90 degrees C as compared to untreated APL. The chaperon like activity of NP was evident from entropy-enthalpy compensation profile of APL. The upper critical temperature for such compensation was elevated from 50 degrees C to 90 degrees C in presence of NP. This dual role of NP in enhancing activity and conferring thermostability to a functionally impaired enzyme is reported for the first time.