C-Terminal Peptide Modification

A method for providing a cargo to a C-terminal end of a peptide, the method comprising a first stage and a second stage, wherein the first stage comprises reacting the C-terminal end of the peptide with a first reactant in the presence of a first catalyst and first radiation to provide a first intermediate, wherein the first catalyst is configured to decarboxylate the C-terminal end of the peptide in the presence of the first radiation, and wherein the first reactant has a first chemical structure according to formula I:

• wherein R and R′are each independently selected from the group consisting of H, and alkyl groups;
• wherein R″ is an electron withdrawing group comprising a functional group selected from the group consisting of an ester, a thioester, an amide, a ketone, a nitro, a sulfoxide, a sulfone, a phosphate ester, an acylhydrazide, a cyano group, and a trihalogenmethyl group;
• wherein n1 and n2 are each independently selected from the range of 1-2;
• and wherein the second stage comprises exposing the first intermediate to a second reactant, wherein the second reactant has a second chemical structure according to formula II:
• wherein X is O or NH, and wherein R1 comprises the cargo.