[Cloning, expression and identification of Plasmodium vivax Duffy binding protein region II of central China isolate]

To clone a Plasmodium vivax Duffy binding protein critical functional region II (PvDBPII) gene of central China isolate, and to express and identify the recombinant PvDBPII protein in vitro.

PCR was performed to amplify PvDBPII from P. vivax DNA of a central China isolate and the PCR product was inserted into pET28a(+) vector. pET28a-PvDBPII recombinant plasmid was constructed and transformed into E. coli host BL21 (DE3+). IPTG was used to induce the recombinant PvDBPII protein fused with His tag, and the protein was purified by His-NTA affinity chromatography. The recombinant protein was identified by SDS-PAGE and Western blot.

The PCR product of PvDBPII gene was about 1,1 kb, meeting the expectation of predicted fragment size. The recombinant pET28a-PvDBPII plasmid was verified by sequencing that the insertion was correct both in direction and in frame, but with 4 non-synonymous mutations compared to reference P. vivax strain Sal-I. SDS-PAGE, and Western blot analysis showed that the recombinant PvDBPII protein was about 44 kDa, and could be recognized by pooled sera from vivax malaria patients.

The PvDBPII gene of central China isolate is successfully cloned, and recombinant PvDBPII is expressed, thereby providing opportunity for further study on PvDBPII.