Polypeptide Synthesis Using the <i>S</i>-Alkyl Thioester of a Partially Protected Peptide Segment. Synthesis of the DNA-Binding Domain of <i>c</i>-Myb Protein (142–193)–NH2

TLDR

The DNA‑binding domain of c‑Myb protein (142–193) was synthesized using this method to assess its utility. The carboxyl‑side thioester of each peptide segment was transformed into a p‑nitrophenyl ester with silver ions and p‑nitrophenol, then the two segments were condensed. The S‑alkyl thioester approach was developed, allowing purification of partially protected c‑Myb peptide segments and near‑complete coupling to yield a highly purified DNA‑binding domain.

Abstract

Abstract A method for polypeptide synthesis using S-alkyl thioester of a partially protected peptide segment has been developed. The DNA-binding domain of c-Myb protein (142–193) was synthesized by this method to estimate its usefulness. The partially protected peptide segments, Boc–[Lys(Boc)143,144,160]–c-Myb protein(142–163)–SCH2CH2CONH2 and [Lys(Boc)171,182,192]–c-Myb protein(164–193)–NH2, were highly purified from peptides obtained by a solid-phase method. The thioester in the carboxyl component of the peptide segment was converted to the corresponding p-nitrophenyl ester in the presence of silver ions and p-nitrophenol and then the two segments were condensed. The coupling reaction proceeded almost completely yielding a highly-purified product after removal of Boc groups.