Cloning,expression and the immune characterization of panallergen profilin in coco(Cocos nucifera Linnaeus)

Objective:To clone and express panallergen profilin from the pollen of coco(Cocos nucifera Linnaeus).Methods:RT-PCR and RACE methods were applied to clone the full-length panallergen genes from coco pollen and the sequence was analyzed.The specific primers were designed.The ORF of profilin of coco pollen was amplified with RT-PCR and cloned into the expression vector pET 28a.Expression of the recombinant coco pollen profilin was carried out in E.coli BL21(DE3) and the purification of the recombinant protein was performed via affinity chromatography with Ni2+ coupled to sepharose.IgE reactivity to recombinant coco pollen profilin was investigated by immunoblot.Results:The complete sequence of coco pollen profilin was cloned.The sequence was 608 bp and included an open reading frame(396 bp) coding for 131 amino acids.Sequence analysis showed that the deduced protein was an acidic protein with an estimated molecular mass of 14.19 kD and a pI of 4.61.The GeneBank accession number of the clones was EF173598.After overexpressed in E.coli BL21(DE3),the recombinant protein was purified through affinity chromatography with Ni2+ coupled to sepharose.Immunoassay showed that the recombinant allergen has good IgE binding capacity.Conclusion:The profilin of coco pollen is expressed successfully in BL21(DE3),which will be used as a base for further study on coco pollen related allergy.