industrial-chemistry-2018-keynote

4 / 11

Page 32
Notes:
Industrial Chemistry | ISSN: 2469-9764 | Volume 4
17th International Conference on
May 21-22, 2018 | New York, USA
Industrial Chemistry and Water Treatment
Enzyme as useful catalyst for precision synthesis of functional polysaccharide materials
Natural polysaccharides such as cellulose, starch, and chitin are widely distributed in nature and thus considered as the very
important biomass resources. They can also be expected as functional materials, which are applicable in biomedical, tissue
engineering, and environmentally benign fields. Therefore, the efficient methods for synthesis of functional polysaccharides
have attracted much attention to provide new materials employed in such application fields. Enzymatic approaches have
increasingly been important to precisely synthesize functional polysaccharide materials. Phosphorylase is one of the enzymes,
which have been practically employed as catalysts for the synthesis of polysaccharides with well-defined structures.This enzyme
catalyzes enzymatic polymerization of α-D-glucose 1-phosphate (Glc-1-P) as a monomer initiated from the nonreducing
end of maltooligosaccharide primer to produce α(1γ4)-glucan, that is amylose (Figure 1). The author has reported precision
synthesis of functional polysaccharide materials by phosphorylase-catalyzed enzymatic reactions. By means of the property of
spontaneously double helix formation from amyloses, for example, it was reported that the phosphorylase-catalyzed enzymatic
polymerization using the immobilized primers forms network structures composed of the double helix cross-linking points.
In most cases, accordingly, the enzymatic polymerization solutions have turned into hydrogels with high water contents. As
an example, the phosphorylase-catalyzed enzymatic polymerization using the immobilized primers on chitin nanofibers
was investigated to produce amylose-grafted chitin nanofiber hydrogels. On the other hand, the author has also reported
that by means of the phosphorylase-catalyzed enzymatic polymerization using analog substrates as monomers, well-defined
polysaccharides with functional groups are efficiently obtained. For example, phosphorylase isolated from thermophilic
bacteria, Aquifex aerolicus VF5, catalyzed the enzymatic polymerization of α-D-glucosamine 1-phosphate (GlcN-1-P) as a
monomer from maltotriose primer. The enzymatic reaction was accelerated in ammonia buffer containing Mg2+ ion, owing
to the precipitation of inorganic phosphate, giving the high molecular weight aminopolysaccharide, which corresponded to
chitosan stereoisomer.
Biography
Jun-ichi Kadokawa has received his PhD in 1992. He then joined Yamagata University as a Research Associate. From 1996 to 1997, he worked as a Visiting
Scientist at the Max-Planck-Institute for Polymer Research in Germany. In 1999, he became an Associate Professor at Yamagata University and moved to Tohoku
University in 2002. He was appointed as a Professor of Kagoshima University in 2004. His research interests focus on polysaccharide materials. He has received
the Award for Encouragement of Research in Polymer Science (1997) and the Cellulose Society of Japan Award (2009). He has published more than 200 papers
in academic journals.
Jun-ichi Kadokawa
Kagoshima University, Japan
Jun-ichi Kadokawa, Ind Chem 2018, Volume 4
DOI: 10.4172/2469-9764-C1-007