Purification of SUMO-1 modified IκBα and complex formation with NF-κB

► We develop a new strategy which improves purification of sumoylated proteins in E. Coli. ► Our three-step purification procedure can be applied to a wide variety of targets. ► We obtain pure SUMO-1 modified IκBα in milligrams quantities. ► High yield expression is suitable for structural studies.