The Stabilizing Effects of Polyols and Sugars on Porcine Pancreatic Lipase.

Porcine pancreatic lipase (PPL) has been used
as a biocatalyst for many years and is one of the most
widely used enzymes for biotechnological applications;
however, it is a rather complex mixture with various active
enzymes. The present study has been undertaken to
determine the effects of polyols and sugars (cosolvents) on
the thermal stability of PPL preparation. The thermal stability
of PPL exposed to 60�C for 10 min was enhanced in
the presence of cosolvents in terms of both residual specific
activity and conformational stability. Thermal denaturation,
changes in circular dichroism, fluorescence spectra,
apparent kinetic parameters, activity, and preferential
interaction parameter of PPL preparation are discussed in
terms of contributions to the mechanism of thermal stability
and the activity enhancement. Partial specific volume
measurement of PPL in the presence of cosolvents is presented
for the first time. The preferential interaction
parameter (n3) was negative in all cosolvents used, and
maximum hydration was observed in the presence of
trehalose, where the preferential interaction parameter was
-0.076 g/g. The observed increase in the thermal stability
of PPL preparation in the presence of cosolvents is due to
the preferential hydration of the enzyme.