Chemical synthesis of a glycoprotein having an intact human complex-type sialyloligosaccharide under the Boc and Fmoc synthetic strategies

J Am Chem Soc. 2008 Jan 16;130(2):501-10. doi: 10.1021/ja072543f. Epub 2007 Dec 18.


The chemical synthesis of complex glycoproteins is an ongoing challenge in protein chemistry. We have examined the synthesis of a single glycoform of monocyte chemotactic protein-3 (MCP-3), a CC-chemokine that consists of 76 amino acids and one N-glycosylation site. A three-segment native chemical ligation strategy was employed using unprotected peptides and glycopeptide. Importantly, the synthesis required the development of methods for the generation of sialylglycopeptide-alphathioesters. For the sialylglycopeptide-alphathioester segment, we examined and successfully implemented approaches using Fmoc-SPPS and Boc-SPPS. To avoid use of hydrogen fluoride, the Boc approach utilized minimal side chain protection and direct thiolysis of the resin bound peptide. Using these strategies, we successfully synthesized a glycoprotein having an intact and homogeneous complex-type sialyloligosaccharide.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / chemistry*
  • Chemokine CCL7 / chemical synthesis*
  • Fluorenes / chemistry*
  • Formic Acid Esters / chemistry*
  • Glycoproteins / chemical synthesis*
  • Humans
  • Molecular Sequence Data
  • Oligosaccharides / chemistry*


  • Amino Acids
  • Chemokine CCL7
  • Fluorenes
  • Formic Acid Esters
  • Glycoproteins
  • N(alpha)-fluorenylmethyloxycarbonylamino acids
  • Oligosaccharides
  • sialooligosaccharides
  • t-butyloxycarbonyl group