title: Chemoenzyamtic synthesis and self-assembling gelation behavior of amylose-grafted poly(γ-glutamic acid).
abstract: In this study, we investigated chmemoenzymatic synthesis of amylose-grafted poly(γ-glutamic acid) (PGA) as a new artificial saccharide-peptide conjugate composed of two biological macromolecules. Maltooligosaccharide as a primer of enzymatic polymerization by phosphorylase catalysis was first introduced on the PGA main chain by the condensation reaction using the condensing agent in NaOH aq. Thermostable phosphorylase-catalyzed enzymatic polymerization of α-d-glucose 1-phosphate (G-1-P) as a monomer was then performed from the primer chain ends of the product to obtain amylose-grafted PGAs, which formed hydrogels in reaction media depending on the G-1-P/primer feed ratios. The powder X-ray diffraction patterns of lyophilized samples (cryogels) from the hydrogels suggested that the amylose graft chains formed double helixes, which acted as cross-inking points for self-assembling hydrogelation. The scanning electron microscopic images of the cryogels showed regularly controlled porous morphologies. Moreover, pore sizes of the cryogels increased with increasing the G-1-P/primer feed ratios, whereas the degrees of substitution of primer on the PGA main chain did not obviously affect pore sizes.
authors.affiliation: Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Shouji
authors.affiliation: Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan. Electronic address: kadokawa@eng.kagoshima-u.ac.jp.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Kadokawa
mesh_terms: D000688:Amylose / Q000737:chemistry*; D029063:Aquifoliaceae / Q000201:enzymology; D060326:Chemistry Techniques, Synthetic; D005782:Gels; D008320:Maltose / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D006005:Phosphorylases / Q000378:metabolism*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D058105:Polymerization; D016062:Porosity
chemical_list: D005782:Gels; D009844:Oligosaccharides; D010455:Peptides; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D008320:Maltose; D000688:Amylose; D006005:Phosphorylases
keywords: Amylose; Chemoenzymatic; Enzymatic polymerization; Gelation; Graft copolymer; Poly(γ-glutamic acid)