Protein Synthesis Using S-Alkyl Thioester of Partially Protected Peptide Segments. Synthesis of DNA-Binding Protein of Bacillus stearothermophilus

Abstract

Abstract Using partially protected peptide thioesters as building blocks, we synthesized HU-type DNA-binding protein of Bacillus stearothermophilus. Four peptide segments, Boc–[Lys(Boc)3]–HBs(1–15)–SCH2CH2CONH2, iNoc–[Lys(Boc)18,19,23,38]–HBs(16–39)–SCH2CH2CONH2, iNoc–[Lys(Boc)41,59]–HBs(40–60)–SCH2CH2CONH2, [Lys(Boc)75,80,83,86,90]–HBs(61–90) were prepared using peptides obtained by a solid-phase method. A partially protected peptide thioester was condensed to a peptide with a free amino group by converting the thioester to the corresponding active ester in the presence of silver ions and N-hydroxysuccinimide. Finally, highly pure synthetic HBs(1–90) was obtained.