Expression of M Protein from LP02/C Equine Arteritis Virus Inhibits Growth of Escherichia Coli M15-pQE30 System

Abstract

Our objective was to obtain Equine Arteritis Virus M protein in prokaryotic system to test it as immunogen. LP02/C Equine Arteritis Virus cDNA was used astemplate to obtain and clone this protein. Equine Arteritis M protein was cloned in the expression vector pQE30 and the recombinant plasmid pQE30/M wastransformed in Escherichia Coli M15 cells. The OD600 values of the IPTG-induced M15-pQE30/M culture showed an inhibition of the kinetics growth comparedwith the non-induced M15-pQE30/M and positive M15-pQE40/DHFR cultures. Several factors such as growth temperature, IPTG concentration and differentinductors were analyzed but any of them showed an improvement in protein expression. Instead of E. coli M15strain, a new strain (E. coli BL21) was used andtransformed with the pQE30/M. This resolved in part the growth inhibition observed in E. coli M15 cells, but no the recovery yield of the protein. So, as all geneproducts that affect cells kinetics growth are considered to be toxic, we argue that the lower yields in M protein recovery could be attributed to an associated toxicityof EAV-M protein from LP02/C strain in this expression system.