Combinatorial Synthesis of MUC1 Glycopeptides:  Polymer Blotting Facilitates Chemical and Enzymatic Synthesis of Highly Complicated Mucin Glycopeptides

Abstract

The chemoselective polymer blotting method allows for rapid and efficient synthesis of glycopeptides based on a "catch and release" strategy between solid-phase and water-soluble polymer supports. We have developed a heterobifunctional linker sensitive to glutamic acid specific protease (BLase). The general procedure consists of five steps, namely (i) the solid-phase synthesis of glycopeptide containing BLase sensitive linker, (ii) subsequent deprotections and the release of the glycopeptide from the resin, (iii) chemoselective blotting of the glycopeptide intermediates in the presence of water-soluble polymers with oxylamino functional groups, (iv) sugar elongations using glycosyltransferases, and (v) the release of target glycopeptides from the polymer platform by selective BLase promoted hydrolysis. The combined use of the solid-phase chemical syntheses of peptides and the enzymatic syntheses of carbohydrates on water-soluble polymers would greatly contribute to the production of complicated glycopeptide libraries, thereby enhancing applicative research. We report here a high-throughput synthetic system for the various types of MUC1 glycopeptides exhibiting a variety of sugar moieties. It is our belief that this concept will become part of the entrenched repertoire for the synthesis of biologically important glycopeptides on the basis of glycosyltransferase reactions in automated and combinatorial syntheses.

Addressing the glycan complexity by using mass spectrometry: In the pursuit of decoding glycologic

“…Furthermore, drug discovery based on the identified pharmacophore seems more promising [34,35]. The importance of utilizing combinatorial library is also recognized in the glycan research field, which is still extremely challenging [27][28][29]31,32,34,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50].…”

Auf dem Weg zur automatisierten Oligosaccharid‐ Synthese

“…[196] Dieser Transporter ist ein multifunktioneller Linker, der entweder als Markierungsgruppe dient, um das Glycopeptid am Polymer anzuheften, oder als Spaltstelle, die die Freisetzung des Produkts vom Polymer erleichtert. Diese Technik ließ sich auf die kombinatorische Synthese einer MUC1-Glycopeptidbibliothek mit 36 Strukturvarianten anwenden.…”

Oligosaccharide Synthesis on Solid, Soluble Polymer, and Tag Supports

“…Nishimura and coworkers have developed the catch-and-release strategy between solid-phase and water-soluble polymer supports, the so-called polymer blotting method, which allows the rapid and efficient synthesis of glycopeptides. 101 The method involves (i) conventional solid-phase synthesis of glycopeptides that contain mono-, di-, and trisaccharides on Thr or Ser residues and Blase (glutamic acid-specific protease)-sensitive amino acid sequence, (ii) removal of the protecting groups and release from the resin, (iii) attachment of the released glycopeptides to the water-soluble polymers via oxime anchor, (iv) sugar elongations using glycosyltransferases, and (v) cleavage of the desired glycopeptides from the soluble supports by Blase-mediated hydrolysis. They have applied three glycosyltransferases, namely, b(1,4)-galactosyltransferase, a(2,3)-(O)-sialyltransferase, and a(2,3)-(N)-sialyltransferase, and successfully prepared 6 kinds of the parallel and 36 kinds of combinatorial libraries of MUC1 mucin glycopeptides.…”