Synthesis of GalNAc-Oligonucleotide Conjugates Using GalNAc Phosphoramidite and Triple-GalNAc CPG Solid Support

Methods Mol Biol. 2021:2282:101-118. doi: 10.1007/978-1-0716-1298-9_7.

Abstract

GalNAc oligonucleotide conjugates demonstrate improved potency in vivo due to selective and efficient delivery to hepatocytes in the liver via receptor-mediated endocytosis. GalNAc-siRNA and GalNAc-antisense oligonucleotides are at various stages of clinical trials, while the first two drugs were already approved by FDA. Also, GalNAc conjugates are excellent tools for functional genomics and target validation in vivo. The number of GalNAc residues in a conjugate is crucial for delivery as cooperative interaction of several GalNAc residues with asialoglycoprotein receptor enhances delivery in vitro and in vivo. Here we provide a robust protocol for the synthesis of triple GalNAc CPG solid support and GalNAc phosphoramidite, synthesis and purification of RNA conjugates with multiple GalNAc residues either to 5'-end or 3'-end and siRNA duplex formation.

Keywords: CPG; GalNAc; N-Acetylgalactosamine; Phosphoramidite; RNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylgalactosamine / analogs & derivatives
  • Acetylgalactosamine / chemical synthesis*
  • Immobilized Nucleic Acids / chemical synthesis*
  • Oligodeoxyribonucleotides / chemical synthesis*
  • Organophosphorus Compounds / chemical synthesis*
  • RNA, Small Interfering / chemical synthesis*
  • Research Design
  • Workflow

Substances

  • CPG-oligonucleotide
  • Immobilized Nucleic Acids
  • Oligodeoxyribonucleotides
  • Organophosphorus Compounds
  • RNA, Small Interfering
  • phosphoramidite
  • Acetylgalactosamine