title: Chain transfer reaction catalyzed by various polyhydroxyalkanoate synthases with poly(ethylene glycol) as an exogenous chain transfer agent.
abstract: Polyhydroxyalkanoate (PHA) synthases catalyze chain transfer (CT) reaction after polymerization reaction of PHA by transferring PHA chain from PHA synthase to a CT agent, resulting in covalent bonding of CT agent to PHA chain at the carboxyl end. Previous studies have shown that poly(ethylene glycol) (PEG) is an effective exogenous CT agent. This study aimed to compare the effects of PEG on CT reaction during poly[(R)-3-hydroxybutyrate] [P(3HB)] synthesis by using six PHA synthases in Escherichia coli JM109. The synthesized P(3HB) polymers were characterized in terms of molecular weight and end-group structure. Supplementation of PEG to the culture medium reduced P(3HB) molecular weights by up to 96% due to PEG-induced CT reaction. The P(3HB) polymers were subjected to (1)H NMR analysis to confirm the formation of a covalent bond between PEG and P(3HB) chain at the carboxyl end. This study revealed the reactivity of PHA synthases to PEG with respect to CT reaction in E. coli.
authors.affiliation: Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tomizawa
authors.forename: Yuta
authors.initials: Y
authors.lastname: Saito
authors.forename: Manami
authors.initials: M
authors.lastname: Hyakutake
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Hideki
authors.initials: H
authors.lastname: Abe
authors.forename: Takeharu
authors.initials: T
authors.lastname: Tsuge
mesh_terms: D000217:Acyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001395:Azotobacter / Q000145:classification / Q000201:enzymology / Q000235:genetics; D001410:Bacillus megaterium / Q000145:classification / Q000201:enzymology / Q000235:genetics; D001419:Bacteria / Q000737:chemistry / Q000145:classification / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002384:Catalysis; D020118:Cupriavidus necator / Q000145:classification / Q000201:enzymology / Q000235:genetics; D020605:Delftia acidovorans / Q000145:classification / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D010802:Phylogeny; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D054813:Polyhydroxyalkanoates; D011092:Polyethylene Glycols; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase