Aim: This study aimed to investigate the existence of phospholipase-A (PLA) activity in
Soluble L. major Antigens (SLA) because of no reports for it so far. Liposomes were used as sensors to
evaluate PLA activity.
Objectives: Liposomal SLA consisting of Egg Phosphatidylcholine (EPC) or Sphingomyelin (SM) were
prepared by two different methods in different pH or temperatures and characterized by Dynamic Light
Scattering (DLS) and Thin Layer Chromatography (TLC).
Methods: Lipid hydrolysis led to the disruption of EPC liposomal SLA in both methods but the Film
Method (FM) produced more stable liposomes than the Detergent Removal Method (DRM).
Result: The preparation of EPC liposomal SLA at pH 6 via FM protected liposomes from hydrolysis to
some extent for a short time. EPC liposomes but not SM liposomes were disrupted in the presence of SLA.
Conclusion: Therefore, a phospholipid without ester bond such as SM should be utilized in liposome
formulations containing PLA as an encapsulating protein.