Fig. 1.

Cartoon of the light-directed immobilization of a His-tagged protein on a microarray using the autoinhibition method. An undecapeptide construct (green) is created with a nickel-tris-(nitrilotriacetic acid) multivalent head group (nickel-tris-NTA) at the N terminus and a His-tag at the C terminus. Included within the peptide sequence is the photocleavable amino acid 3-amino-3-(2-nitrophenyl)-propionic acid and a single Cys for attachment of the construct to a microarray (or other molecules, in further applications). Initially, the construct is in the autoinhibited state. Irradiation (280–400 nm) cleaves the backbone of the construct and treatment with a competing ligand (imidazole) disrupts the intramolecular self-inactivation. Removal of the autoinhibitory His-tag opens up the nickel-tris-NTA head group for binding of His-tagged proteins.