title: Enzymatic hydrolysis of chemosynthesized atactic poly(3-hydroxybutyrate) by poly(3-hydroxyalkanoate) depolymerase from Acidovorax Sp. TP4 and Ralstonia pickettii T1.
abstract: The enzymatic degradability of chemosynthesized atactic poly([R,S]-3-hydroxybutyrate) [a-P(3HB)] by two types of extracellular poly(3-hydroxyalkanoate) (PHA) depolymerases purified from Ralstonia pickettii T1 (PhaZ(ral)) and Acidovorax Sp. TP4 (PhaZ(aci)), defined respectively as PHA depolymerase types I and II according to the position of the lipase box in the catalytic domain, were studied. The enzymatic degradation of a-P(3HB) by PhaZ(aci) depolymerase was confirmed from the results of weight loss and the scanning electron micrographs. The degradation products were characterized by one- and two-dimension (1)H NMR spectroscopy. It was found that a-P(3HB) could be degraded into monomer, dimer, and trimer by PhaZ(aci) depolymerase at temperatures ranging from 4 to 20 degrees C, while a-P(3HB) could hardly be hydrolyzed by PhaZ(ral) depolymerase in the same temperature range. These results suggested that the chemosynthesized a-P(3HB) could be degraded in the pure state by natural PHA depolymerase.
authors.affiliation: Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Inagawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Osanai
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kasuya
authors.forename: Terumi
authors.initials: T
authors.lastname: Saito
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsumura
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Doi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D016946:Gram-Negative Aerobic Rods and Cocci / Q000201:enzymology; D006868:Hydrolysis; D006885:Hydroxybutyrates / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000378:metabolism*; D013696:Temperature; D000094122:Polyhydroxybutyrates
chemical_list: D002265:Carboxylic Ester Hydrolases; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C077226:poly(3-hydroxyalkanoic acid) depolymerase