One-pot multienzyme-catalyzed assembly of pentasaccharide repeating units from Group B Streptococcus capsular polysaccharides and their related oligosaccharide derivatives

Abstract

The biochemical properties, functional characterization and substrate specificities of five recombinant glycosyltransferases – β-1,3-N-acetylglucosaminyltransferase (Cps1aI), β-1,4-galactosyltransferase (Cps1aJ), β-1,3-galactosyltransferase (Cps1bJ), and α-2,3-sialyltransferases (Cps1aK and Cps1bK) – involved in the biosynthesis of pentasaccharide repeating units of Group B Streptococcus (GBS) serotypes Ia and Ib capsular polysaccharides (CPSs) were systematically investigated. These recombinant enzymes were subsequently employed for a one-pot multi-enzyme cascade system to synthesize the pentasaccharide repeating units of GBS serotypes Ia and Ib CPSs, as well as their oligosaccharide derivatives. Using chemically synthesized Lacα-PP-(CH₂)₁₁-OPh as the initial substrate, the one-pot multi-enzymatic synthesis achieved satisfactory product yields ranging from 70 to 84%.