title: Identification of Fatty Acid Glucose Esters as Os9BGlu31 Transglucosidase Substrates in Rice Flag Leaves.
abstract: Rice Os9BGlu31 transglucosidase transfers glucosyl moieties between various carboxylic acids and alcohols, including phenolic acids and flavonoids, in vitro. The role of Os9BGlu31 transglucosidase in rice plant metabolism has only been suggested to date. Methanolic extracts of rice bran and leaves were found to contain oleic acid and linoleic acid to which Os9BGlu31 could transfer glucose from the 4-nitrophenyl β-D-glucoside (4NPGlc) donor to form 1-O-acyl glucose esters. Os9BGlu31 showed higher activity with oleic acid (18:1) and linoleic acid (18:2) than with stearic acid (18:0) and had both a higher kcat and a higher Km for linoleic than oleic acid in the presence of 8 mM 4NPGlc donor. Os9BGlu31 knockout mutant rice lines were found to have significantly larger amounts of fatty acid glucose esters than wild-type control lines. Because the transglucosylation reaction is reversible, these data suggest that fatty acid glucose esters act as glucosyl donor substrates for Os9BGlu31 transglucosidase in rice.
authors.affiliation: School of Biochemistry, Institute of Science, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.|Center for Biomolecular Structure, Function and Application, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.
authors.forename: Juthamath
authors.initials: J
authors.lastname: Komvongsa
authors.affiliation: Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University , Yongin 446-701, Korea.
authors.forename: Bancha
authors.initials: B
authors.lastname: Mahong
authors.affiliation: School of Biochemistry, Institute of Science, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.|Center for Biomolecular Structure, Function and Application, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.
authors.forename: Kannika
authors.initials: K
authors.lastname: Phasai
authors.affiliation: Center for Biomolecular Structure, Function and Application, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.|Center for Scientific and Technological Equipment, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hua
authors.affiliation: Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University , Yongin 446-701, Korea.
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Jeon
authors.affiliation: School of Biochemistry, Institute of Science, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.|Center for Biomolecular Structure, Function and Application, Suranaree University of Technology , Nakhon Ratchasima 30000, Thailand.
authors.forename: James R
authors.initials: JR
authors.lastname: Ketudat Cairns
mesh_terms: D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D005959:Glucosidases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D019787:Linoleic Acid / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism*; D012275:Oryza / Q000737:chemistry / Q000201:enzymology*; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D019301:Oleic Acid; D019787:Linoleic Acid; D005959:Glucosidases; D005947:Glucose
keywords: fatty acid; flag leaf; rice mutant; tandem mass spectrometry; transglycosidase