Directed formation of lipid membrane microdomains as high affinity sites for His-tagged proteins

Lipid membranes composed of an iminodiacetic acid functionalized lipid, DSIDA, in a POPC matrix has displayed switchable properties by [Cu.sup.2+] recognition to assemble microdomains that has acted as high affinity sets for His-tagged proteins. The microdomains have shown an order of magnitude enhanced affinity for the proteins when compared to homogeneously functionalized POPC membranes with [Ni.sup.2+]-DOIDA, while a rapid release and restoration of the original membrane is accomplished with micromolar concentrations of EDTA.