Kanda P, Wells M A
Chem Phys Lipids. 1986 Jan;39(1-2):31-9. doi: 10.1016/0009-3084(86)90097-6.
Dihexanoylphosphatidylethanolamine (DiC6-PE) was prepared by phospholipase D catalyzed transphosphatidylation of dihexanoylphosphatidylcholine (DiC6-PC). Below the critical micellar concentration the pKa of the amino group is 9.4 +/- 0.05. The critical micellar concentration of the zwitterionic species is 5.3 +/- 0.2 mM, while that of the anionic species is 11.0 +/- 0.05 mM. Based on the pH dependence of the rate of hydroxide ion catalyzed hydrolysis, the second order rate constant for hydrolysis of the zwitterionic species is 0.70 +/- 0.021 s-1 M-1, while that for the anionic species is 0.040 +/- 0.011 s-1 M-1. The pH-dependence of phospholipase A2 catalyzed hydrolysis at substrate concentrations below the critical micellar concentration shows that the zwitterionic species is the preferred substrate, and the anionic species is either a competitive inhibitor of the hydrolysis of the zwitterionic species or poor substrate. DiC6-PE is hydrolyzed by C. adamanteus at about 1% the rate of DiC6-PC.
通过磷脂酶D催化二己酰磷脂酰胆碱（DiC6-PC）的转磷脂酰化反应制备了二己酰磷脂酰乙醇胺（DiC6-PE）。在临界胶束浓度以下，氨基的pKa为9.4±0.05。两性离子物种的临界胶束浓度为5.3±0.2 mM，而阴离子物种的临界胶束浓度为11.0±0.05 mM。根据氢氧根离子催化水解速率对pH的依赖性，两性离子物种水解的二级速率常数为0.70±0.021 s-1 M-1，而阴离子物种的二级速率常数为0.040±0.011 s-1 M-1。在底物浓度低于临界胶束浓度时，磷脂酶A2催化水解的pH依赖性表明两性离子物种是首选底物，而阴离子物种要么是两性离子物种水解的竞争性抑制剂，要么是较差的底物。DiC6-PE被坚硬梭菌水解的速率约为DiC6-PC的1%。
