A Vinylogous Photocleavage Strategy Allows Direct Photocaging of Backbone Amide Structure.

Side-chain modifications that respond to external stimuli provide a convenient approach to control macromolecular structure and function. Responsive modification of backbone amide structure represents a direct and powerful alternative to impact folding and function. Here, we describe a new photocaging method using histidine-directed backbone modification to selectively modify peptides and proteins at the amide N-H bond. A new vinylogous photocleavage method allows photorelease of the backbone modification and, with it, restoration of function.