Exploring The Active Site Cavity Of Human Pancreatic Lipase

Within the scope of improving the efficiency of pancreatic enzyme replacement
therapy in cystic fibrosis, the feasibility of shifting the pH-activity profile
of pancreatic lipase toward acidic values was investigated by site specific
mutagenesis in different regions of the catalytic cavity. We have shown that
introducing a negative charge close to the catalytic histidine induced a shift of
the pH optimum toward acidic values but strongly reduced the lipase activity. On
the other hand, a negative charge in the entrance of the catalytic cleft gives
rise to a lipase with improved properties and twice more active than the native
enzyme at acidic pH.