Targeting Proteins to Curvature Patterned Receptor Lipids

We have shown that coexisting lipid phases, varying in composition, form a pixilated pattern in response to the curvature pattern of an underlying substrate formed by electron beam lithography.  These results are strongly indicative that the transfer of a nanoscale curvature pattern to a compositional lipid pattern may be a viable way of positioning functional groups.  We have moved this technology toward application by using curvature to compositionally pattern phase-specific lipids functionalized with a metal chelating iminodiacetic acid (IDA) headgroup.  The IDA headgroup coordinates to divalent transition-metal ions and sequesters proteins rich with histidine (His) moieties.  Therefore, we characterize the spatial patterning of His-tagged green fluorescent protein (GFP) targeted to phase specific IDA-lipids (such as DSIDA or DOIDA) that are spatially patterned by a nanoscale curvature pattern.  We show that this method can be used to form defect-free arrays of His-GFP, in small areas, suggesting the possibility of using this approach for the localization of protein, DNA, or optically active molecules.  Defects in the His-GFP pattern were also interesting and may be of future use.   We also discuss the general metastability of nanometer-scale lipid compositional patterns.