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.
Colin
Damien Yann
DY
INRA, UMR1260 "Nutriments Lipidiques et Prévention des Maladies Métaboliques", Marseille F-13385, France. Brigitte.Kerfelec@univmed.fr
Deprez-Beauclair
Paule
P
Allouche
Maya
M
Brasseur
Robert
R
Kerfelec
Brigitte
B
D019943:Amino Acid Substitution; D001665:Binding Sites / Q000235:genetics; D002384:Catalysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D013379:Substrate Specificity; D014280:Triglycerides / Q000737:chemistry
D014280:Triglycerides; D008049:Lipase; C518354:PNLIP protein, human; C005830:tributyrin