Chemically Mediated Site-Specific Cleavage of Proteins

Depro-tection occurs readily by treatment with aqueous iodine at 25 °Cvia a presumed iodolactone intermediate. We reasoned thatanalogous cleavage should take place in proteins containingallylglycine (Figure 1), thus permitting site-specific proteincleavage. While not normally a protein constituent, allylglycineis not dramatically different in physicochemical properties thanleucine, isoleucine, and valine; its incorporation into specific sitesin proteins may be envisioned by readthrough of a nonsensecodon