Chemo-Enzymatic Synthesis of a Glycopolymer Carrying Clustered-N-ACETYL-β-lactosamine Moieties

Abstract

Abstract A polyacrylamide derivative having a β-linked N-acetyllactosamine moiety, a major component of oligosaccharide chains of glycoproteins, on each repeating unit was synthesized via a chemo-enzymatic process. p-Nitrophenyl N-acetyl-β-lactosaminide was prepared by an one-step enzymatic synthesis, using a β-galactosidase as catalyst, from p-nitrophenyl N-acetyl-β-d-glucosaminide as the glycosyl acceptor and lactose as the glycosyl donor. The nitro group was reduced to an amino function, which was then allowed to react with either acryloyl chloride or acrylic acid. The resulting p-acryloylaminophenyl N-acetyl-β-lactosaminide was polymerized with azobisisobutyronitrile as initiator in dimethyl sulfoxide to give a homopolymer with a number-average molecular weight ( M n ) of 3.2 × 105. High molecular-weight polymers carrying α-lactose, N-acetyl-β-d-glucosamine, and α-d-glucopyranose were also synthesized as reference polymers in similar manners. Solution properties of these poly-p-acryloylaminophenyl der...