Conformational flexibility of a Candida Rugosa Lipase studied by electronic spectroscopies techniques

FUSIÑOS, P.; PICÓ, G.

VALNATURA Valorization of Natural Resources

Universidade de Minho

Lugar: Braga Portugal; Año: 2008; p. 61 - 68

We have used second-order orthogonal designs to obtain empirical models that describe the pH and temperature influence on lipase Lip1 from Candida rusosa secondary structure. Important variations in the secondary structure was found with the different media assayed. Contrary, minor changes were observed with the incubation time. This behaviour suggests that the modifications in the secondary structure of the protein is consequence of conformational changes induced by the media and not the result of a progressive denaturation. In addition, the thermal unfolding of lipase at different pH values was followed by measuring the circular dichroims signal as function of temperature over a temperature range of 20¨C80¡ãC. The results have showed a melting temperature of 61.9¡ãC at pH 5.5 , while at pHs 7.0  and 8.6 were 53.6¡ãC and 33.9 ¡ãC respectively. The optimum experimental conditions for stability were found at 38 ¡ãC and pH 9.0 at zeto incubation ime of the enzyme, while after 1 h of incubation at a temperature of 48 ¡ãC the optimun condition of stability were a pH and T  values 45 ¡ãC and 9.0 respectively.