The thermal stability of rNSs was monitored in a Jasco-815 spectropolarimeter fitted with Peltier thermal control system (PTC-423S). 0.2 mg/ml of the purified protein in 20 mM Tris-HCl pH 8.0 and 100 mM NaCl was heated from 10uC to 100uC. The change in molar ellipticity at 222 nm was monitored as a function of temperature to obtain the thermal melting curve. The ellipticity was measured at 222 nm using 0.2 mg/ml protein in a 0.1 cm path length cuvette with band width of 1 nm and response time of 1 sec. The temperature was raised at a rate of 2uC/minute from 10-100uC.