Precision synthesis of reducing-end thiol-modified cellulose enabled by enzyme selection

Abstract Enzyme-catalyzed iterative ? -1,4-glycosylation of -glycosides is promising for bottom-up polymerization reducing-end-modified cello-oligosaccharide chains. Self-assembly the chains from solution yields crystalline nanocellulose materials with properties that are tunable by glycoside group used. Cellulose a reducing-end thiol interest to install controllable pattern site-selective modifications into material. Selection polymerizing enzyme (cellodextrin phosphorylase; CdP) was pursued here enhance synthetic precision -1-thio-glucose conversion generate pure “1-thio-cellulose” (?95%) unencumbered plain (unlabeled) cellulose resulting enzymatic side reactions. The CdP Clostridium stercorarium ( Cs 21 times more active on (0.17 U/mg; 45 °C) than cellulosi Cc CdP), and it lacked hydrolase activity, which substantial in CdP, against ?- d -glucose 1-phosphate donor substrate. combination these indicated practical catalyst 1-thio-cellulose synthesis directly (8 h; 25 mol% yield) does not require second (cellobiose phosphorylase), essential when using less selective CdP. had an average degree ?10 were assembled highly II crystallinity