Triazinic dye ligand selection by surface plasmon resonance for recombinant lactoferricin purification

Abstract

Bovine lactoferricin (Lfcin B) belongs to the antimicrobial peptide family, which is the first line of defense against pathogens in many organisms. Lfcin B has important applications due to its antiviral, antifungal, antiparasitic, anticancer/tumor and antibacterial activity. In this work, we tested five triazine dyes for Lfcin B affinity interactions using Surface Plasmon Resonance (SPR) technology. Red HE-3B and Yellow HE-4R dyes were selected and immobilized on a Sepharose-4B matrix for further purification studies. Recombinant Lfcin B was expressed as a fusion protein with Glutathione -S- Transferase (Lfcin B-GST) by using baculovirus expression vector system and the dye-Sepharose matrices were assayed for Lfcin B-GST adsorption and subsequent elution. The Yellow HE-4R-Sepharose matrix was specific for Lfcin B and allowed adsorption of Lfcin B-GST directly from the culture medium even at high salt concentration. This novel application of SPR to screen possible dye-peptide interactions could be relevant to purify other peptides or proteins by using low-cost dye-affinity chromatography.