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Kaushik Ghose - One of the best experts on this subject based on the ideXlab platform.
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identification and functional characterization of a flax udp Glycosyltransferase glucosylating secoisolariciresinol seco into secoisolariciresinol monoglucoside smg and diglucoside sdg
BMC Plant Biology, 2014Co-Authors: Jason Mccallum, Marva Sweeneynixon, Kumarakurubaran Selvaraj, Chris Kirby, Kaushik Ghose, Sylvie Cloutier, Michael K Deyholos, Raju DatlaAbstract:Lignans are a class of diphenolic nonsteroidal phytoestrogens often found Glycosylated in planta. Flax seeds are a rich source of secoisolariciresinol diglucoside (SDG) lignans. Glycosylation is a process by which a Glycosyl Group is covalently attached to an aglycone substrate and is catalyzed by uridine diphosphate Glycosyltransferases (UGTs). Until now, very little information was available on UGT genes that may play a role in flax SDG biosynthesis. Here we report on the identification, structural and functional characterization of 5 putative UGTs potentially involved in secoisolariciresinol (SECO) glucosylation in flax. Five UGT genes belonging to the Glycosyltransferases’ family 1 (EC 2.4.x.y) were cloned and characterized. They fall under four UGT families corresponding to five sub-families referred to as UGT74S1, UGT74T1, UGT89B3, UGT94H1, UGT712B1 that all display the characteristic plant secondary product Glycosyltransferase (PSPG) conserved motif. However, diversity was observed within this 44 amino acid sequence, especially in the two peptide sequences WAPQV and HCGWNS known to play a key role in the recognition and binding of diverse aglycone substrates and in the sugar donor specificity. In developing flax seeds, UGT74S1 and UGT94H1 showed a coordinated gene expression with that of pinoresinol-lariciresinol reductase (PLR) and their gene expression patterns correlated with SDG biosynthesis. Enzyme assays of the five heterologously expressed UGTs identified UGT74S1 as the only one using SECO as substrate, forming SECO monoglucoside (SMG) and then SDG in a sequential manner. We have cloned and characterized five flax UGTs and provided evidence that UGT74S1 uses SECO as substrate to form SDG in vitro. This study allowed us to propose a model for the missing step in SDG lignan biosynthesis.
Raju Datla - One of the best experts on this subject based on the ideXlab platform.
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identification and functional characterization of a flax udp Glycosyltransferase glucosylating secoisolariciresinol seco into secoisolariciresinol monoglucoside smg and diglucoside sdg
BMC Plant Biology, 2014Co-Authors: Jason Mccallum, Marva Sweeneynixon, Kumarakurubaran Selvaraj, Chris Kirby, Kaushik Ghose, Sylvie Cloutier, Michael K Deyholos, Raju DatlaAbstract:Lignans are a class of diphenolic nonsteroidal phytoestrogens often found Glycosylated in planta. Flax seeds are a rich source of secoisolariciresinol diglucoside (SDG) lignans. Glycosylation is a process by which a Glycosyl Group is covalently attached to an aglycone substrate and is catalyzed by uridine diphosphate Glycosyltransferases (UGTs). Until now, very little information was available on UGT genes that may play a role in flax SDG biosynthesis. Here we report on the identification, structural and functional characterization of 5 putative UGTs potentially involved in secoisolariciresinol (SECO) glucosylation in flax. Five UGT genes belonging to the Glycosyltransferases’ family 1 (EC 2.4.x.y) were cloned and characterized. They fall under four UGT families corresponding to five sub-families referred to as UGT74S1, UGT74T1, UGT89B3, UGT94H1, UGT712B1 that all display the characteristic plant secondary product Glycosyltransferase (PSPG) conserved motif. However, diversity was observed within this 44 amino acid sequence, especially in the two peptide sequences WAPQV and HCGWNS known to play a key role in the recognition and binding of diverse aglycone substrates and in the sugar donor specificity. In developing flax seeds, UGT74S1 and UGT94H1 showed a coordinated gene expression with that of pinoresinol-lariciresinol reductase (PLR) and their gene expression patterns correlated with SDG biosynthesis. Enzyme assays of the five heterologously expressed UGTs identified UGT74S1 as the only one using SECO as substrate, forming SECO monoglucoside (SMG) and then SDG in a sequential manner. We have cloned and characterized five flax UGTs and provided evidence that UGT74S1 uses SECO as substrate to form SDG in vitro. This study allowed us to propose a model for the missing step in SDG lignan biosynthesis.
Kumarakurubaran Selvaraj - One of the best experts on this subject based on the ideXlab platform.
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identification and functional characterization of a flax udp Glycosyltransferase glucosylating secoisolariciresinol seco into secoisolariciresinol monoglucoside smg and diglucoside sdg
BMC Plant Biology, 2014Co-Authors: Jason Mccallum, Marva Sweeneynixon, Kumarakurubaran Selvaraj, Chris Kirby, Kaushik Ghose, Sylvie Cloutier, Michael K Deyholos, Raju DatlaAbstract:Lignans are a class of diphenolic nonsteroidal phytoestrogens often found Glycosylated in planta. Flax seeds are a rich source of secoisolariciresinol diglucoside (SDG) lignans. Glycosylation is a process by which a Glycosyl Group is covalently attached to an aglycone substrate and is catalyzed by uridine diphosphate Glycosyltransferases (UGTs). Until now, very little information was available on UGT genes that may play a role in flax SDG biosynthesis. Here we report on the identification, structural and functional characterization of 5 putative UGTs potentially involved in secoisolariciresinol (SECO) glucosylation in flax. Five UGT genes belonging to the Glycosyltransferases’ family 1 (EC 2.4.x.y) were cloned and characterized. They fall under four UGT families corresponding to five sub-families referred to as UGT74S1, UGT74T1, UGT89B3, UGT94H1, UGT712B1 that all display the characteristic plant secondary product Glycosyltransferase (PSPG) conserved motif. However, diversity was observed within this 44 amino acid sequence, especially in the two peptide sequences WAPQV and HCGWNS known to play a key role in the recognition and binding of diverse aglycone substrates and in the sugar donor specificity. In developing flax seeds, UGT74S1 and UGT94H1 showed a coordinated gene expression with that of pinoresinol-lariciresinol reductase (PLR) and their gene expression patterns correlated with SDG biosynthesis. Enzyme assays of the five heterologously expressed UGTs identified UGT74S1 as the only one using SECO as substrate, forming SECO monoglucoside (SMG) and then SDG in a sequential manner. We have cloned and characterized five flax UGTs and provided evidence that UGT74S1 uses SECO as substrate to form SDG in vitro. This study allowed us to propose a model for the missing step in SDG lignan biosynthesis.
Jaroslav Píš - One of the best experts on this subject based on the ideXlab platform.
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Cyclic boronates in the mass spectrometry of ecdysteroids
Rapid Communications in Mass Spectrometry, 1993Co-Authors: Tomáš Vaisar, Jaroslav PíšAbstract:For the structural elucidation of ecdysteroids a reaction with phenylboronic acid has been employed. This reaction takes place exclusively on the C20,C22 diol moiety, thus facilitating fast and easy detection of this moiety in the molecule od ecdysteroid. This derivatization also redirects fragmentation to C17/C20 bond cleavage with charge retention on both fragments enabling assessment of the structure both of the steroid nucleus and of the side-chain. Possible reaction of phenylboronic acid with the diol moiety of the Glycosyl Group of the glycoside od ecdysteroid, producing di-adduct, is demonstrated; participation of the 5β-hydroxy Group of 5β,20-dihydroxyecdysone in the formation of such a di-adduct is discussed; and the role of theenol form of the 6-carbonyl Group is proved.
Zygmunt Sidorczyk - One of the best experts on this subject based on the ideXlab platform.
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Structure of a New N-acetylisomuramic Acid-Containing O-specific Polysaccharide of Proteus Penneri Strains 19 and 35
Carbohydrate research, 1996Co-Authors: Sof'ya N. Senchenkova, Alexander S. Shashkov, Yuriy A. Knirel, Nikolay K. Kochetkov, Krystyna Zych, Zygmunt SidorczykAbstract:O-Specific polysaccharides, together with oligosaccharide products of their degradation, were isolated by GPC after mild acid delipidation of lipopolysaccharides of Proteus penneri strains 19 and 35. The polysaccharides had the same trisaccharide repeating unit containing one residue each of D-galactose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-3-O-[(S)-1-carboxyethyl]-2-deoxy-D-glucose (N-acetylisomuramic acid). On the basis of 1D and 2D 1H and 13C NMR spectroscopy, including 2D correlation spectroscopy (COSY), rotating-frame NOE spectroscopy (ROESY), and H-detected heteronuclear 1H,13C multiple-quantum coherence (HMQC), the following structure of the repeating unit was established: [formula: see text]. The oligosaccharide products formed by cleavage of the glycosidic linkage of GlcNAc represent a chemical trisaccharide repeating unit of the polysaccharide and its oligomer homologs. The ease of hydrolysis of the polysaccharide is associated with the closeness of the Glycosyl Group and the lactic acid residue in N-acetylisomuramic acid. The polysaccharides studied are structurally related to the O-specific polysaccharides of P. penneri strains 62 and 71 studied by us earlier.