Evaluation of the recombinant turkey pancreatic lipase phospholipase activity: A monolayer study.
Classical lipases are well known for being enzymes hydrolysing triacylglycérols as substrate, except the porcine pancreatic lipase (PPL) which was able to hydrolyze phosphatidylcholine. Amino acid sequence alignments revealed that Valine 260 residue in PPL lid, postulated to be responsible for the PPL phospholipase activity, was present in the Turkey pancreatic lipase (TPL). The importance of Val 260 in the phospholipase activities expression has been reported. To confirm this fact, Val 260 was mutated to Alanine in the TPL lid. Mutated protein has conserved its phospholipase activity as well as the non mutated TPL. Therefore, Valine 260 residue in the lid is not involved in the pancreatic lipases phospholipase activity. The rTPL phospholipase activity was also studied using monolayer technique. This avian pancreatic lipase has shown phospholipase activity toward differently charged phospholipids. The highest phospholipase activity was found on phosphatidylglycerol (negatively charged substrate) at a surface pressure of 20mN/m, but when a zwitterionic substrate was used (DLPC), a lower activity was found at a surface pressure of 10mN/m. However, it is worth noticing that the TPL phospholipase activity is about 100 fold lower than its lipase activity. GC chromatography analyses of the released fatty acids from the hydrolysis of 1,2-POPC have shown that rTPL hydrolyses esters bonds at the sn-1 as well as the sn-2 position of phospholipids. Hence, rTPL shows a low phospholipase activity in comparison to its activity toward triacylglycerols.
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Université de Sfax, ENIS Route de Soukra, BPW, 1173 Sfax, Tunisia.
Madiha
M
Bou Ali
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Université de Sfax, ENIS Route de Soukra, BPW, 1173 Sfax, Tunisia.
Raida
R
Jallouli
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Université de Sfax, ENIS Route de Soukra, BPW, 1173 Sfax, Tunisia.
Youssef
Y
Gargouri
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Université de Sfax, ENIS Route de Soukra, BPW, 1173 Sfax, Tunisia. Electronic address: yassine_marseille@yahoo.fr.
Yassine
Y
Ben Ali
D000818:Animals; D002384:Catalysis; D004789:Enzyme Activation; D006868:Hydrolysis; D007700:Kinetics; D008066:Lipolysis; D008958:Models, Molecular; D008968:Molecular Conformation; D020799:Pancrelipase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins; D013379:Substrate Specificity; D014422:Turkeys
D010713:Phosphatidylcholines; D010743:Phospholipids; D011994:Recombinant Proteins; D020799:Pancrelipase; D010740:Phospholipases
Mutation; Pancreatic lipase; Phospholipase activity