Enzymatic Synthesis of 2-(β-Galactosyl)-ethyl Methacrylate by β-Galactosidase from Pyrococcus woesei and Application for Glycopolymer Synthesis and Lectin Studies

Biomacromolecules. 2020 Feb 10;21(2):974-987. doi: 10.1021/acs.biomac.9b01647. Epub 2020 Jan 28.

Abstract

Glycosidases have long been used for the synthesis of glycosides by transglycosylation reactions. Especially glycosidases from hyperthermophilic bacteria are useful for reactions under extreme reaction conditions, e.g., in the presence of organic solvents. We herein report the facile enzymatic synthesis and purification of 2-(β-galactosyl)-ethyl methacrylate (Gal-EMA) with the recombinant hyperthermostable glycosidase from Pyrococcus woesei in high yields. Optimized reaction conditions resulted in gram-scale synthesis of the galactosylated monomer with 88% transglycosylation yield. The product Gal-EMA was characterized by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS), nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy. Gal-EMA was utilized to synthesize sugar-functionalized acrylate polymers with defined amounts of incorporated galactose (0-100%). Analysis of the binding affinity of the lectin RCA120 from Ricinus communis to the glycopolymers using an enzyme-linked lectin assay (ELLA) revealed KD values between 0.24 and 6.2 nM, depending on the amount of incorporated Gal-EMA. The potential of Gal-EMA for the synthesis of acrylate-functionalized glycan oligomers was demonstrated by sequential elongation of the terminal galactose by two glycosyltransferases, resulting in the terminal glycan N-acetyllactosamine (LacNAc) epitope. In conclusion, the enzymatic synthesis of Gal-EMA opens new routes to a series of novel monomeric building blocks for the synthesis of glycan-functionalized polyacrylates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Lectins / chemical synthesis
  • Lectins / metabolism*
  • Methacrylates / chemical synthesis
  • Methacrylates / metabolism*
  • Polymers / chemical synthesis
  • Polymers / metabolism*
  • Pyrococcus / enzymology*
  • Spectrometry, Mass, Electrospray Ionization / methods
  • beta-Galactosidase / chemical synthesis
  • beta-Galactosidase / metabolism*

Substances

  • Lectins
  • Methacrylates
  • Polymers
  • beta-Galactosidase