Role of urea on recombinant Apo A-I stability and its utilization in anion exchange chromatography.

摘要: Apolipoprotein A-I (Apo A-I) is an important lipid-binding protein involved in the transport and metabolism of cholesterol. High purity, particular with respect to endotoxins required for therapeutic applications. The use urea during purification process recombinant Apo produced Escherichia coli has been suggested so as provide high endotoxin clearance. In this work, we show that can be used a sole modifier ion exchange chromatographic investigate molecular mechanism elution by correlating effect on self-association, conformation adsorption equilibrium properties modified model A-I. absence was found present population oligomers represented mainly trimers, hexamers nonamers. addition induced oligomer dissociation structure unfolding. We correlated changes association variations strong anion exchanger. It confirmed isotherms, described Langmuir model, were dependent both concentrations. Monomers, observed at low concentration (0.5M), characterized larger binding affinity capacity compared (0M) unfolded monomers (2-8M). reduction strength maximum concentrations than 0.5M explains ability inducing from resin. complexes occurring could likely origin effective clearance originally trapped inside oligomers.