[Analysis and Identification of Peptide Epitope of the Fifth Stage Larvae of Angiostrongylus Cantonensis].

OBJECTIVE:To identify the specific antigens of the fifth stage larvae (larvae V) of Angiostrongylus cantonensis in soluble proteins.METHODS:The techniques of two-dimensional electrophoresis (2-DE) and immunoblot were employed to analyze the soluble components of larvae V antigens. The resulting protein spots were identified by mass spectrometry and the specific antigen and immunogenic peptide segment profiles determined.Larvae V was identified by immunoblot of peptide immune murine sera.RESULTS:Immunoblot of 2-DE showed that there were 8 specific antigen spots in females and 4 in males of larvae V. The 12 protein spots had a pH range of 5-7 and a molecular weight of 24-40 kD. Among 12 spot, actin-1 and galectin-1 were identified successfully. And a peptide (NH2-KNGDIALHFNPRFDEK) was predicted as epitope and synthesized. The binding capacity of murine immune sera could identify the 32 000 of larvae V.CONCLUSIONS:Galectin and actin are common antigens of female and male larvae V of A.cantonensis. And a peptide from galectin-1 may become a potential target for immunologic diagnosis and immunological mediator.