OPTIMIZATION OF REFOLDING CONDITIONS FOR RECOMBINANT OMP19 PROTEIN FROM BRUCELLA SPP.

Abstract

The recombinant Omp19 protein of Brucella spp. is considered as a promising antigen for the development of diagnostic test systems and immunobiological preparations. However, obtaining its soluble form remains a significant challenge. The aim of this study was to optimize the dialysis conditions for the recombinant Omp19 protein following purification by ion-exchange chromatography.Dialysis was performed sequentially in several buffer systems with varying compositions of salts and stabilizing components. Dialysis efficiency and protein solubility were assessed using the SDS-PAGE method, with analysis of the supernatant and pellet fractions under various storage temperature conditions. The results showed that when buffers 1-4 were used, the recombinant protein predominantly converted to an insoluble form and was detected in the pellet. To increase the protein’s solubility, the concentration of L-arginine in the dialysis buffer was optimized. It was found that using a buffer containing 880 mM Larginine ensured that the protein remained in the soluble fraction and prevented the formation of a visible pellet.Based on these results, we recommend using 880 mM L-arginine to stabilize the recombinant Omp19 protein during purification and storage, which is of practical importance for the further use of this protein in diagnostics and biotechnology research.