A simple and cost Effectively Method for Production of Recombinant of Full Length of Human Placenta-Specific Protein using E. coli BL21 strain

Abstract

Placenta-specific protein 1 (PLAC1) is one of the most significant cancer/testis antigens with restricted expression in the placenta and testis and high expression in a wide range of human cancers. PLAC1 has fundamental roles in cancer progression and is suggested as a diagnostic biomarker and therapeutic target for many cancers. However, producing full length of recombinant PLAC1 (rPLAC1) in E. coli BL21 strain as soluble form with maintaining its efficacy is still limited. Yet, major issues such as inclusion bodies (IBs) formation must be overcome. Here, we try to address this issue by optimizing rPLAC1 expression conditions. We purified rPLAC1 by immobilized metal affinity chromatography (IMAC) without using urea and detected the production of rPLAC1 by SDS-PAGE and western blot (WB). Our results demonstrated that the optimum conditions for the production of the full length of rPLAC1 in E. coli BL21 are induction at the early-log phase of growth (O.D600nm=0.3-0.5) using 0.5 mM IPTG at induction temperature of 22 °C for 7-8 hours. Moreover, we indicated that optimization of induction conditions probably increases protein-soluble form yield without needing to use urea or any denaturing buffer in purification later. Taken together, we have introduced a simple and cost effectively method for the production of the full length of human rPLAC1 and increasing its soluble form without using urea.