SYNTHESIS OF HUMAN C-TYPE NATRIURETIC PEPTIDE-22 USING CHLOROTRITYL RESIN AND TETRAFLUOROBORIC ACID DEPROTECTION

Human C-type natriuretic peptide 22 (hCNP22), the third member of the natriuretic peptide family, was efficiently synthesized by Fmoc-based peptide chain construction on a 2-chlorotrityl (Clt) resin, followed b y deprotection using tetrafluoroboric acid (HBF4). The use of Clt resi n was effective in suppressing racemization at the C-terminal cysteine residue caused by the base treatment for Fmoc-cleavage. The disulfide bond of hCNP22 was constructed using the silyl chloride-sulfoxide met hod to avoid oxidation at the Met residue, Using amino acid- and dipep tide-resin derivatives, the effects of bases, protecting groups and re sin supports on the racemization at the C-terminal Cys residue were ex amined in detail.