Hydrolysis of Phosphatidylcholine in Aerosol-OT/Isooctane Reversed Micelles by Phospholipase $A_2$

역미셀계내에서 인지질분해효소 $A_2$에 의한 레시친의 가수분해

  • Chang, Pahn-Shick (Department of Food Science and Technology, Seoul National Polytechnic University)
  • 장판식 (서울산업대학교 식품공학과)
  • Published : 1997.02.01

Abstract

Bee venom (Apis mellifera) phospholipase $A_2$ solubilized in reversed micelles containing small amount of water stabilized by surfactant could catalyze the hydrolysis of dipalmitoyl phosphatidylcholine (DPPC). A sensitive and simple high performance liquid chromatographic (HPLC) methodology of phospholipase $A_2$ assay for the hydrolysis of DPPC was developed. Kinetic analysis of the phospholipase $A_2$-catalyzed reaction was found to be possible in reversed micelles. Among the surfactants and organic solvents tested, aerosol-OT and isooctane were most effective for the hydrolysis of DPPC in reversed micelles. Optimal temperature, optimal pH, $K_{m,app.},\;V_{max.,app.}$ and activation energy were determined to be $35{\sim}40^{\circ}C$, 7.0, 8.73 mM, 2.83 units/㎎ protein and 12.31 kcal/mole, respectively. The hydrolysis activity was dependent on water content and maximum activity was obtained at R value (=[water]/[aerosol-OT]) of 10.0.

Keywords

phospholipase $A_2$;HPLC;lysophosphatidylcholine;reversed micelles