Development of crosslink‐type tag‐probe pairs for fluorescent imaging of proteins

Abstract

Abstract Useful methods of protein labeling via functional peptide tags have been developed in the field of proteome and chemical biology. New tag‐probe pairs based on leucine zipper peptides for labeling target proteins are described. These consist of an α‐helical probe peptide with an environmental‐sensitive fluorescent dye and two antiparallel α‐helical tag peptides, and may be crosslinked, from the Cys residue of the tag peptide to the N α ‐chloroacetyl group of the probe peptide. Binding of the probe peptide to the tag peptides results in movement of the fluorophore from a hydrophilic to a hydrophobic environment inside the leucine zipper structure, causing a dramatic fluorescent change, mediated by the binding of the two peptides. As a spacer between the N α ‐chloroacetyl group and the original probe sequence, a single Gly residue was the most suitable among 0‐2 Gly residues. Crosslinking leads to superior fluorescence response, binding affinity, and chemical stability. These ZIP tag‐probe pairs are useful for labeling and fluorescent imaging of proteins. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 843–852, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com