title: Purification and biochemical characterization of an acid-stable lipase from the pyloric caeca of sardine (Sardinella aurita).
abstract: A lipolytic activity was located in the sardine digestive glands (pyloric caeca), from which a sardine digestive lipase (SaDL) was purified. Pure SaDL has a molecular mass of 43 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The enzyme was found to be more active on short-chain triacylglycerols than on long-chain ones. SaDL does not present the interfacial activation phenomenon. Control experiments were performed under the same experimental conditions, with dromedary and turkey pancreatic lipases and showed a positive interfacial activation phenomenon. Sodium deoxycholate (NaDC) has an inhibitory effect on the lipase activity. The pure enzyme lost 40% of its activity in presence of 8 mM NaDC. SaDL was found to be mostly stable at low pH values. Interestingly, no colipase was detected in the sardine pyloric caeca. Analogous results were reported for the scorpion and the crab digestive systems. This is in line with the idea that colipase might has evolved in mammal animals simultaneously with the appearance of an exocrine pancreas. No similarity was found between the NH(2)-terminal amino acid residues of SaDL and those of lipases from the digestive tract of other species. Altogether, these results suggest that SaDL is a member of a new group of lipases belonging to aquatic species.
authors.affiliation: Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS route de Soukra, 3038 Sfax, Tunisia.
authors.forename: Nabil
authors.initials: N
authors.lastname: Smichi
authors.forename: Ahmed
authors.initials: A
authors.lastname: Fendri
authors.forename: Raja
authors.initials: R
authors.lastname: Chaâbouni
authors.forename: Faouzi
authors.initials: F
authors.lastname: Ben Rebah
authors.forename: Youssef
authors.initials: Y
authors.lastname: Gargouri
authors.forename: Nabil
authors.initials: N
authors.lastname: Miled
mesh_terms: D000143:Acids / Q000378:metabolism*; D000645:Ammonium Sulfate / Q000494:pharmacology; D000818:Animals; D002432:Cecum / Q000187:drug effects / Q000201:enzymology*; D011232:Chemical Precipitation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004789:Enzyme Activation / Q000187:drug effects; D004795:Enzyme Stability / Q000187:drug effects; D005399:Fishes / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D015151:Immunoblotting; D007783:Lactones / Q000494:pharmacology; D008049:Lipase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D008066:Lipolysis / Q000187:drug effects; D000077403:Orlistat; D011708:Pylorus / Q000187:drug effects / Q000201:enzymology*; D012694:Serine / Q000378:metabolism; D013696:Temperature
chemical_list: D000143:Acids; D007783:Lactones; D012694:Serine; D000077403:Orlistat; D008049:Lipase; D000645:Ammonium Sulfate