[Mass spectrometry identification and immune cross-reactivity of a minor shrimp allergen-sarcoplasmic calcium binding protein from Litopenaeus vannamei].

AIM: To identify sarcoplasmic calcium-binding protein(SCP) as a minor shrimp allergen by mass spectrometry,and to analyze the immune cross-reactivity among crustacean SCPs.METHODS: The Mr 21 000 allergen from Litopenaeus vannamei was identified by MALDI-TOF/TOF-MS.BLAST and ClustalW were used to compare amino acid sequence identity of the allergen among crustaceans.The puritifed Mr 21 000 allergen was injected subcutaneously in mice to produce the specific polyclonal antibodies to analyze immune cross-reactivity of the allergen with proteins from 8 other species of crustaceans by Western blotting.RESULTS: The Mr 21 000 shrimp allergen was identified as SCP.Sequence comparison revealed that SCP had 81%-100% amino acid identity among crustaceans.Western blotting showed that the proteins with Mr about 21 000,corresponding to SCP from Metapenaeus ensis,Penaeus monodon,Oratosquilla oratoria,Macrobrachium rosenbergii,Procambarus clarkii,Portunus pelagicus,Charybdis feriatus,Eriocheir sinensis were recognized by polyclonal antibodies against SCP of Litopenaeus vannamei.CONCLUSION: SCP is a minor shrimp allergen,and SCPs have a high sequence homology and strong immune cross-reactivity among crustaceans,which can be used as detective,diagnostic and safe immunotherapeutic agents for subjects with shrimp allergy.