Synthesis of a secretoglobin 3A2 type C (98–139) fragment by Dawson’s native chemical ligation

Abstract A secretoglobin 3A2 type C (98–139) peptide was synthesized by native chemical ligation between 115 Ile and 116 Cys residues using Dawson’s linker. The peptide- N -acyl-benzimidazolinone-glycine amide, a C -terminal thioesters precursor, was provided from 3-amino-4-(methylamino)benzoic acid. In addition, an N -terminal cysteine fragment, the (116–139) peptide, was prepared by ordinary Fmoc-solid phase peptide synthesis. Native chemical ligation of the (98–115) fragment with the Dawson’s linker and the (116–139) peptide smoothly proceeded to give SCGB3A2 type C (98–139) peptide.