DROMEDARY PANCREATIC LIPASE - PURIFICATION AND STRUCTURAL-PROPERTIES

Dromedary pancreatic lipase was purified from delipidated pancreases. Pure dromedary pancreatic lipase (glycerol ester hydrolase, EC 3.1.1.3 ) was obtained after ammonium sulfate fractionation, Sephadex G-100 ge l filtration, anion-exchange (Mono Q Sepharose) and size exclusion col umn using high performance liquid chromatography (HPLC). The pure lipa se is a monomer and has a molecular mass of about 45 kD and a pI of ar ound 4.8. A specific activity of 5900 U/mg was measured on tributyrin as substrate at 37 degrees C in the presence of colipase and 2 mM NaTD C. The first 11 N-terminal amino acid residues and 10 peptides obtaine d by endoproteinase Glu-C digestion were sequenced. Dromedary pancreat ic lipase is very similar to other pancreatic lipases as compared with their N-terminal and some peptides sequences. DrPL is activated by in terfaces. The interfacial activation could be related to the presence of a lid and in fact one fragment of this lid domain (P9) was sequence d here: its' role will be discussed below.