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The New Phytologist Sep 2021Wood of coniferous trees (softwood), is a globally significant carbon sink and an important source of biomass. Despite that, little is known about the genetic basis of...
Wood of coniferous trees (softwood), is a globally significant carbon sink and an important source of biomass. Despite that, little is known about the genetic basis of softwood cell wall biosynthesis. Branching of xylan, one of the main hemicelluloses in softwood secondary cell walls, with glucuronic acid (GlcA) is critical for biomass recalcitrance. Here, we investigate the decoration patterns of xylan by conifer GlucUronic acid substitution of Xylan (GUX) enzymes. Through molecular phylogenetics we identify two distinct conifer GUX clades. Using transcriptional profiling we show that the genes are preferentially expressed in secondary cell wall forming tissues. With in vitro and in planta assays we demonstrate that conifer GUX enzymes from both clades are active glucuronyltransferases. Conifer GUX enzymes from each clade have different specific activities. While members of clade one add evenly spaced GlcA branches, the members of clade two are also capable of glucuronidating two consecutive xyloses. Importantly, these types of xylan patterning are present in softwood. As xylan patterning might modulate xylan-cellulose and xylan-lignin interactions, our results further the understanding of softwood cell wall biosynthesis and provide breeding or genetic engineering targets that can be used to modify softwood properties.
Topics: Arabidopsis; Cell Wall; Glucuronic Acid; Plant Breeding; Tracheophyta; Xylans
PubMed: 34086997
DOI: 10.1111/nph.17531 -
Angewandte Chemie (International Ed. in... Jan 2023Heparan sulfate (HS) has multifaceted biological activities. To date, no libraries of HS oligosaccharides bearing systematically varied sulfation structures are...
Heparan sulfate (HS) has multifaceted biological activities. To date, no libraries of HS oligosaccharides bearing systematically varied sulfation structures are available owing to the challenges in synthesizing a large number of HS oligosaccharides. To overcome the obstacles and expedite the synthesis, a divergent approach was designed, where 64 HS tetrasaccharides covering all possible structures of 2-O-, 6-O- and N-sulfation with the glucosamine-glucuronic acid-glucosamine-iduronic acid backbone were successfully produced from a single strategically protected tetrasaccharide intermediate. This extensive library helped identify the structural requirements for HS sequences to have strong fibroblast growth factor-2 binding but a weak affinity for platelet factor-4. Such a strategy to separate out these two interactions could lead to new HS-based potential therapeutics without the dangerous adverse effect of heparin-induced thrombocytopenia.
Topics: Oligosaccharides; Heparitin Sulfate; Protein Binding; Glucuronic Acid; Glucosamine
PubMed: 36173931
DOI: 10.1002/anie.202211985 -
BMC Research Notes Jul 2019Mitragynine is the main active compound of Mitragyna speciose (Kratom in Thai). The understanding of mitragynine derivative metabolism in human body is required to...
OBJECTIVE
Mitragynine is the main active compound of Mitragyna speciose (Kratom in Thai). The understanding of mitragynine derivative metabolism in human body is required to develop effective detection techniques in case of drug abuse or establish an appropriate dosage in case of medicinal uses. This in silico study is based upon in vivo results in rat and human by Philipp et al. (J Mass Spectrom 44:1249-1261, 2009).
RESULTS
Gas-phase structures of mitragynine, 7-hydroxymitragynine and their metabolites were obtained by quantum chemical method at B3LYP/6-311++G(d,p) level. Results in terms of standard Gibbs energies of reaction for all metabolic pathways are reported with solvation energy from SMD model. We found that 7-hydroxy substitution leads to changes in reactivity in comparison to mitragynine: position 17 is more reactive towards demethylation and conjugation with glucuronic acid and position 9 is less reactive towards conjugation with glucuronic acid. Despite the changes, position 9 is the most reactive for demethylation and position 17 is the most reactive for conjugation with glucuronic acid for both mitragynine and 7-hydroxymitragynine. Our results suggest that 7-hydroxy substitution could lead to different metabolic pathways and raise an important question for further experimental studies of this more potent derivative.
Topics: Animals; Computer Simulation; Demethylation; Glucuronic Acid; Humans; Metabolic Networks and Pathways; Mitragyna; Models, Chemical; Molecular Structure; Rats; Secologanin Tryptamine Alkaloids; Substance Abuse Detection; Substance-Related Disorders
PubMed: 31331383
DOI: 10.1186/s13104-019-4461-3 -
Pathobiology : Journal of... 2013Islet transplantation has been shown to be a viable treatment option for patients afflicted with type 1 diabetes. However, the lack of availablity of human pancreases... (Review)
Review
Islet transplantation has been shown to be a viable treatment option for patients afflicted with type 1 diabetes. However, the lack of availablity of human pancreases and the need to use risky immunosuppressive drugs to prevent transplant rejection remain two major obstacles to the routine use of islet transplantation in diabetic patients. Successful development of a bioartificial pancreas using the approach of microencapsulation with perm-selective coating of islets in hydrogels for graft immunoisolation holds tremendous promise for diabetic patients because it has great potential to overcome these two barriers. In this review article, we will discuss the need for a bioartificial pancreas, provide a detailed description of the microencapsulation process, and review the status of the technology in clinical development. We will also critically review the various factors that will need to be taken into consideration in order to achieve the ultimate goal of routine clinical application.
Topics: Alginates; Diabetes Mellitus, Type 1; Drug Compounding; Glucuronic Acid; Graft Rejection; Hexuronic Acids; Humans; Islets of Langerhans Transplantation; Pancreas; Pancreas, Artificial
PubMed: 23652283
DOI: 10.1159/000345873 -
Organic & Biomolecular Chemistry Apr 2014Although hundreds of heparan sulfate (HS) binding proteins have been implicated in a myriad of physiological and pathological processes, very little information is known...
Although hundreds of heparan sulfate (HS) binding proteins have been implicated in a myriad of physiological and pathological processes, very little information is known about ligand requirements for binding and mediating biological activities by these proteins. We report here a streamlined approach for the preparation of modular disaccharide building blocks that will facilitate the assembly of libraries of HS oligosaccharides for structure-activity relationship studies. In particular, we have found that glucuronic acid donors, which usually perform poorly in glycosylations, can give high yields of coupling products when the C-2 hydroxyl is protected with a permanent 4-acetoxy-2,2-dimethyl butanoyl- (PivOAc) or temporary levulinoyl (Lev) ester and the C-4 hydroxyl modified with a selectively removable 2-methylnaphthyl (Nap) ether. It has been shown that the PivOAc ester can be removed without affecting sulfate esters making it an ideal protecting group for HS oligosaccharide assembly. Iduronic acid donors exhibit more favorable glycosyl donating properties and a compound protected with a Lev ester at C-2 and an Fmoc function at the C-4 hydroxyl gave coupling products in high yield. The new donors avoid post-glycosylation oxidation and therefore allow the facile preparation of modular disaccharide building blocks.
Topics: Carbohydrate Conformation; Glucuronic Acid; Glycosylation; Oligosaccharides; Sulfates
PubMed: 24549353
DOI: 10.1039/c3ob42312c -
Clinical and Translational Science Jul 2020The pharmacokinetic (PK) properties of drugs are affected in several ways by interactions with microbiota. The aim of this study was to investigate the effects of oral...
The pharmacokinetic (PK) properties of drugs are affected in several ways by interactions with microbiota. The aim of this study was to investigate the effects of oral vancomycin on the gut microbiota and, consequently, on the PKs of simvastatin. An open-label, single arm, sequential crossover study was conducted in six healthy Korean male subjects. After 6 days on a control diet, simvastatin 40 mg was orally administered to the subjects before and after 1 week of oral vancomycin treatment. Blood samples for PK analysis and fecal samples for metagenomic and metabolomic analyses were collected. After vancomycin treatment, the richness of microbiota considerably decreased, and the composition was altered. In particular, the relative abundance of Bacteroidetes decreased, whereas that of proteobacteria increased. In addition, changes in fecal metabolites, including D-glucuronic acid, were observed. However, systemic exposure of simvastatin was not changed whereas that of hydroxysimvastatin showed a tendency to increase. The relationship between the change of PKs of simvastatin and the change of gut microbiota and fecal metabolites were not clearly observed.
Topics: Administration, Oral; Adult; Anti-Bacterial Agents; Bacteroidetes; Cross-Over Studies; Drug Interactions; Feces; Gastrointestinal Microbiome; Glucuronic Acid; Healthy Volunteers; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Metabolomics; Middle Aged; Proteobacteria; Simvastatin; Vancomycin; Young Adult
PubMed: 32058642
DOI: 10.1111/cts.12761 -
Journal of the American Society For... Oct 2008Electron detachment dissociation (EDD) Fourier transform mass spectrometry has recently been shown to be a powerful tool for examining the structural features of...
Electron detachment dissociation (EDD) Fourier transform mass spectrometry has recently been shown to be a powerful tool for examining the structural features of sulfated glycosaminoglycans (GAGs). The characteristics of GAG fragmentation by EDD include abundant cross-ring fragmentation primarily on hexuronic acid residues, cleavage of all glycosidic bonds, and the formation of even- and odd-electron product ions. GAG dissociation by EDD has been proposed to occur through the formation of an excited species that can undergo direct decomposition or ejects an electron and then undergoes dissociation. In this work, we perform electron-induced dissociation (EID) on singly charged GAGs to identify products that form via direct decomposition by eliminating the pathway of electron detachment. EID of GAG tetrasaccharides produces cleavage of all glycosidic bonds and abundant cross-ring fragmentation primarily on hexuronic acid residues, producing fragmentation similar to EDD of the same molecules, but distinctly different from the products of infrared multiphoton dissociation or collisionally activated decomposition. These results suggest that observed abundant fragmentation of hexuronic acid residues occurs as a result of their increased lability when they undergo electronic excitation. EID fragmentation of GAG tetrasaccharides results in both even- and odd-electron products. EID of heparan sulfate tetrasaccharide epimers produces identical fragmentation, in contrast to EDD, in which the epimers can be distinguished by their fragment ions. These data suggest that for EDD, electron detachment plays a significant role in distinguishing glucuronic acid from iduronic acid.
Topics: Electrons; Fourier Analysis; Glucuronic Acid; Glycosaminoglycans; Heparitin Sulfate; Hexuronic Acids; Iduronic Acid; Ions; Isomerism; Molecular Structure; Oligosaccharides; Tandem Mass Spectrometry
PubMed: 18657442
DOI: 10.1016/j.jasms.2008.06.024 -
The Journal of Biological Chemistry Apr 2009A second dermatan sulfate epimerase (DS-epi2) was identified as a homolog of the first epimerase (DS-epi1), which was previously described by our group. DS-epi2 is 1,222...
A second dermatan sulfate epimerase (DS-epi2) was identified as a homolog of the first epimerase (DS-epi1), which was previously described by our group. DS-epi2 is 1,222 amino acids long and has an approximately 700-amino acid N-terminal epimerase domain that is highly conserved between the two enzymes. In addition, the C-terminal portion is predicted to be an O-sulfotransferase domain. In this study we found that DS-epi2 has epimerase activity, which involves conversion of d-glucuronic acid to l-iduronic acid (EC 5.1.3.19), but no O-sulfotransferase activity was detected. In dermatan sulfate, iduronic acid residues are either clustered together in blocks or alternating with glucuronic acid, forming hybrid structures. By using a short interfering RNA approach, we found that DS-epi2 and DS-epi1 are both involved in the biosynthesis of the iduronic acid blocks in fibroblasts and that DS-epi2 can also synthesize the hybrid structures. Both iduronic acid-containing domains have been shown to bind to several growth factors, many of which have biological roles in brain development. DS-epi2 has been genetically linked to bipolar disorder, which suggests that the dermatan sulfate domains generated by a defective enzyme may be involved in the etiology of the disease.
Topics: Amino Acid Sequence; Cell Line; Cells, Cultured; Dermatan Sulfate; Fibroblasts; Glucuronic Acid; Golgi Apparatus; Humans; Iduronic Acid; Molecular Sequence Data; Plasmids; Protein Structure, Tertiary; RNA, Small Interfering; Racemases and Epimerases; Sulfotransferases
PubMed: 19188366
DOI: 10.1074/jbc.M809339200 -
PloS One 2016Alginate, the main cell-wall polysaccharide of brown algae, is composed of two residues: mannuronic acid (M-residues) and, its C5-epimer, guluronic acid (G-residues)....
Alginate, the main cell-wall polysaccharide of brown algae, is composed of two residues: mannuronic acid (M-residues) and, its C5-epimer, guluronic acid (G-residues). Alginate lyases define a class of enzymes that cleave the glycosidic bond of alginate by β-elimination. They are classified according to their ability to recognize the distribution of M- and G-residues and are named M-, G- or MG-lyases. In the CAZy database, alginate lyases have been grouped by sequence similarity into seven distinct polysaccharide lyase families. The polysaccharide lyase family PL6 is subdivided into three subfamilies. Subfamily PL6_1 includes three biochemically characterized enzymes (two alginate lyases and one dermatan sulfatase lyase). No characterized enzymes have been described in the two other subfamilies (PL6_2 and PL6_3). To improve the prediction of polysaccharide-lyase activity in the PL6 family, we re-examined the classification of the PL6 family and biochemically characterized a set of enzymes reflecting the diversity of the protein sequences. Our results show that subfamily PL6_1 includes two dermatan sulfates lyases and several alginate lyases that have various substrate specificities and modes of action. In contrast, subfamilies PL6_2 and PL6_3 were found to contain only endo-poly-MG-lyases.
Topics: Alginates; Amino Acid Sequence; Computational Biology; Crystallography, X-Ray; Databases, Protein; Glucuronic Acid; Hexuronic Acids; Membrane Proteins; Phaeophyceae; Phylogeny; Polysaccharide-Lyases; Sequence Homology, Amino Acid; Structure-Activity Relationship; Substrate Specificity
PubMed: 27438604
DOI: 10.1371/journal.pone.0159415 -
The Journal of Biological Chemistry Oct 2002We found a novel glycosyltransferase gene having a hypothetical beta 1,4-galactosyltransferase motif (GenBank accession number ) by a BLAST search and cloned its...
Enzymatic synthesis of chondroitin with a novel chondroitin sulfate N-acetylgalactosaminyltransferase that transfers N-acetylgalactosamine to glucuronic acid in initiation and elongation of chondroitin sulfate synthesis.
We found a novel glycosyltransferase gene having a hypothetical beta 1,4-galactosyltransferase motif (GenBank accession number ) by a BLAST search and cloned its full-length open reading frame using the 5'-rapid amplification of cDNA ends method. The truncated form was expressed in insect cells as a soluble enzyme. It transferred N-acetylgalactosamine, not galactose, to para-nitrophenyl-beta-glucuronic acid. The N-acetylgalactosamine-glucuronic acid linkage has been identified only in chondroitin sulfate; therefore, we examined its chondroitin elongation and initiation activities. N-Acetylgalactosaminyltransferase activity was observed toward chondroitin poly- and oligosaccharides, chondroitin sulfate oligosaccharides, and linkage tetrasaccharide (GlcA-Gal-Gal-Xyl-O-methoxyphenyl), and the chondroitin polysaccharide and linkage tetrasaccharide were better acceptor substrates than the others. Northern blot analysis and quantitative real-time PCR analysis revealed that its 4-kb transcripts were highly expressed in thyroid and placenta, although they were ubiquitously expressed in various tissues and cells. These results suggest that this enzyme has N-acetylgalactosaminyltransferase activity in both the elongation and initiation of chondroitin sulfate synthesis. Furthermore, we performed enzymatic synthesis of chondroitin pentasaccharide in vitro. In one tube reaction with four enzymes, beta 1,4-galactosyltransferase-VII, beta 1,3-galactosyltransferase-VI, glucuronyltransferase-I, and this enzyme, and a synthetic xylose-peptide acceptor, the structure GalNAc-GlcA-Gal-Gal-Xyl-peptide was constructed. This is the first report of a chondroitin pentasaccharide constructed with recombinant glycosyltransferases in vitro.
Topics: Acetylgalactosamine; Amino Acid Sequence; Chondroitin; Chromatography, High Pressure Liquid; Glucuronic Acid; Humans; Molecular Sequence Data; N-Acetylgalactosaminyltransferases; Recombinant Fusion Proteins; Sequence Alignment; Spectrometry, Mass, Electrospray Ionization; Tissue Distribution
PubMed: 12163485
DOI: 10.1074/jbc.M203619200