Native laser lithography of His-tagged proteins by uncaging of multivalent chelators

We report a generic approach for targeting proteins into micropatterns by in situ laser lithography. To this end, we have designed a photocleavable oligohistidine peptide for caging tris(nitrilo triacetic acid) (tris-NTA) groups on surfaces by multivalent interactions. Local photofragmentation of the peptide by UV illumination through a photomask or by a confocal laser beam uncages tris-NTA, thus generating free binding sites for rapid, site-specific capturing of His-tagged proteins into micropatterns. Iterative writing of proteins by laser lithography enabled for assembly of multiplexed functional protein microstructures on surfaces. Thus, versatile, user-defined protein micropatterns can be assembled under physiological conditions with a standard confocal laser-scanning microscope.