CHO-KI 細胞의 Lysophospholipase 活性에 關한 硏究 = Characterization of Lysophospholipases from a CHO-Kl Cell

다국어 초록 (Multilingual Abstract)

Lysophospholipase (E.C. 3.1.1.5) are widely distributed in prokaryotic and eukaryotic cells and are hypothesized to have an appreciable role in the metabolism of phospholipids by degrading potentially cytotoxic lysophospholipids generated by the action of phospholipase A₁/A₂. In the present study, lysophospholipase L₁(A₁) and lysophospholipase L₂(A₂) activities in chinese hamster ovary cell subclone(CHO-KI) that hydrolyze 1-acyl-lyso PC, 1-acyl-lyso PE, and 2-acyl-lyso PE were dectected and chracterized. These two enzymes were membrane associated enzymes and did not require Ca2+ ion for optimal activity. Lysophospholipase L₁show optimum pH 7.0, and lysophospholipase L₂ show broad optimum pH 6-9. These two enzymes were completely inhibited by -SH reagent, p-chloromercuriebenzoic acid (PCMB)and serine protease inhibitor, diisopropylfluorophosphate (DFP) and ionic and nonionic detergents. Substrate specificity of these two enzymes using 1-[14C] LPE, 1-[14C] LPC as substrate for lysophospholipase L₁, and 2-[14C] LPE, 1-[14C] LPC as substrate for lysophospholipase L₁, and 2-[14C] LPE, 1-[14C] LPC as substrate for lysophospholipase L₂, these two enzymes more preferentially hydrolyzed lyso PE than lyso PC. Lysophospholipase L₁ has transacylase activity.
Abbreviation : EDTA, ethylene diamine tetra acetic acid
Lyso PA, lysophosphatidic acid
Lyso PS, lysophosphatidylserine
PC, phosphatidylcholine
PE , phosphatidylethanolamine
Lyso PC, lysophosphatidylcholine
Lyso PE , lysophosphatidylethanolamine