title: Enzymes as Green Catalysts for Precision Macromolecular Synthesis.
abstract: The present article comprehensively reviews the macromolecular synthesis using enzymes as catalysts. Among the six main classes of enzymes, the three classes, oxidoreductases, transferases, and hydrolases, have been employed as catalysts for the in vitro macromolecular synthesis and modification reactions. Appropriate design of reaction including monomer and enzyme catalyst produces macromolecules with precisely controlled structure, similarly as in vivo enzymatic reactions. The reaction controls the product structure with respect to substrate selectivity, chemo-selectivity, regio-selectivity, stereoselectivity, and choro-selectivity. Oxidoreductases catalyze various oxidation polymerizations of aromatic compounds as well as vinyl polymerizations. Transferases are effective catalysts for producing polysaccharide having a variety of structure and polyesters. Hydrolases catalyzing the bond-cleaving of macromolecules in vivo, catalyze the reverse reaction for bond forming in vitro to give various polysaccharides and functionalized polyesters. The enzymatic polymerizations allowed the first in vitro synthesis of natural polysaccharides having complicated structures like cellulose, amylose, xylan, chitin, hyaluronan, and chondroitin. These polymerizations are "green" with several respects; nontoxicity of enzyme, high catalyst efficiency, selective reactions under mild conditions using green solvents and renewable starting materials, and producing minimal byproducts. Thus, the enzymatic polymerization is desirable for the environment and contributes to "green polymer chemistry" for maintaining sustainable society.
authors.affiliation: Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University , Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Shoda
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University , Yamadaoka, Suita 565-0871, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uyama
authors.affiliation: Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University , Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kadokawa
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Center for Fiber & Textile Science, Kyoto Institute of Technology , Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D055162:Biocatalysis; D055772:Green Chemistry Technology; D006867:Hydrolases / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D014166:Transferases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D010088:Oxidoreductases; D014166:Transferases; D006867:Hydrolases