Expression of the Lactate Dehydrogenase Gene fromEptatretus okinoseanusinEscherichia coli

Amplified Eptatretus okinoseanus cDNA was digested with NdeI and EcoRI, cloned into pCold trigger factor (TF), and transformed with Escherichia coli strain BL 21 in which a csp A promoter was introduced to inhibit the expression of foreign peptides. Recombinant lactate dehydrogenase (LDH) was obtained in the soluble fraction after sonication of the cells. The protein was digested by HRC 3C protease, thrombin, and factor Xa. The specific activity of TF-tagged protein and tagless protein were  mIU/mg and  mIU/mg, respectively. The deletion of the TF tag enhanced the activity compared with the native protein to  mIU/mg, showing that this expression method is effective for the mass production of the protein to allow further study of the structure of LDH.