Cloning and expression of gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH) antigen of Edwardsiella ictaluri in E. coli BL21 (DE3)

Abstract

In this study, we successfully cloned and expressed the gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH) antigen protein of Edwardsiella ictaluri isolated from tissue samples of bacillary necrosis diseased striped catfish (Pangasianodon hypophthalmus) in An Giang province, Viet Nam. The gene encoding GAPDH antigen was cloned into vector pGEM®-T Easy and expressed with vector pET200/D-TOPO in Escherichia coli BL21 (DE3) cells. The results of sequencing showed that the nucleotide sequence of GAPDH gene was 996 bp in length, encoding a polypeptide with 331 amino acid residues, and 99% similarity to the polypeptide chain of recorded GAPDH antigen in GenBank (accession
number: AVZ80933.1). The result of expressed protein analysis on 15% sodium dodecyl sulfate-polyacrylamide (SDS-PAGE) gel showed that molecular mass of fusion protein was approximately 39 kDa, and direct ELISA determined that expressed protein was the 6xHisGAPDH recombinant protein.