Synthesis of highly ordered cellulose II in vitro using cellodextrin phosphorylase

Area of Science:

• Biochemistry
• Materials Science
• Polymer Chemistry

Background:

• In vitro cellulose synthesis offers control over material properties compared to natural sources.
• Cellodextrin phosphorylase (CDP) is an enzyme involved in cellulose metabolism.
• Glucose was previously not considered an effective acceptor for CDP-mediated synthesis.

Purpose of the Study:

• To investigate the enzymatic synthesis of cellulose II using glucose as a substrate.
• To characterize the structure and properties of the synthesized cellulose.
• To explore the role of cellodextrin phosphorylase (CDP) in cellulose production from glucose.

Main Methods:

• Enzymatic synthesis using cellodextrin phosphorylase (CDP), glucose, and alpha-glucose 1-phosphate (alphaG1P).
• (1)H NMR spectroscopy to determine the average degree of polymerization (DP).
• Transmission electron microscopy (TEM), electron diffraction, and X-ray diffraction for structural analysis.

Main Results:

• Significant precipitation of insoluble cellulose II occurred when glucose was used as an acceptor with CDP.
• The synthesized cellulose exhibited high crystallinity and an average DP of nine.
• Platelet-shaped single lamellar crystals of cellulose II, several micrometers in length, were observed.

Conclusions:

• Cellodextrin phosphorylase (CDP) can synthesize cello oligosaccharides with an average DP of nine from glucose.
• The in vitro synthesized cello oligosaccharides precipitate as highly crystalline cellulose II.
• This study demonstrates a novel method for producing tailor-made, highly crystalline cellulose II.