Structural and enzymatic analyses of a glucosyltransferase Alr3699/HepE involved in Anabaena heterocyst envelop polysaccharide biosynthesis
Formation of the heterocyst envelope polysaccharide (HEP) is a key process for cyanobacterial heterocyst differentiation. The maturation of HEP in Anabaena sp. strain PCC 7120 is controlled by a gene cluster termed HEP island in addition to an operon alr3698-alr3699, which encodes two putative proteins termed Alr3698/HepD and Alr3699/HepE. Here we report the crystal structures of HepE in the apo-form and three complex forms that bind to UDP-glucose (UDPG), UDP&glucose, and UDP, respectively. The overall structure of HepE displays a typical GT-B fold of glycosyltransferases, comprising two separate β/α/β...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Wang, X.-P., Jiang, Y.-L., Dai, Y.-N., Cheng, W., Chen, Y., Zhou, C.-Z. Tags: Structural Biology Source Type: research
The valine and lysine residues in the conserved FxVTxK motif are important for the function of phylogenetically distant plant cellulose synthases
Cellulose synthases (CESAs) synthesize the β-1,4-glucan chains that coalesce to form cellulose microfibrils in plant cell walls. In addition to a large cytosolic (catalytic) domain, CESAs have eight predicted transmembrane helices (TMHs). However, analogous to the structure of BcsA, a bacterial CESA, predicted TMH5 in CESA may instead be an interfacial helix. This would place the conserved FxVTxK motif in the plant cell cytosol where it could function as a substrate-gating loop as occurs in BcsA. To define the functional importance of the CESA region containing FxVTxK, we tested five parallel mutations in Arabidopsis ...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Slabaugh, E., Scavuzzo-Duggan, T., Chaves, A., Wilson, L., Wilson, C., Davis, J. K., Cosgrove, D. J., Anderson, C. T., Roberts, A. W., Haigler, C. H. Tags: Plant Biology Source Type: research
Acinetobacter baumannii K27 and K44 capsular polysaccharides have the same K unit but different structures due to the presence of distinct wzy genes in otherwise closely related K gene clusters
Capsular polysaccharides (CPSs), from Acinetobacter baumannii isolates 1432, 4190 and NIPH 70, which have related gene content at the K locus, were examined, and the chemical structures established using 2D 1H and 13C NMR spectroscopy. The three isolates produce the same pentasaccharide repeat unit, which consists of 5-N-acetyl-7-N-[(S)-3-hydroxybutanoyl] (major) or 5,7-di-N-acetyl (minor) derivatives of 5,7-diamino-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic (legionaminic) acid (Leg5Ac7R), d-galactose, N-acetyl-d-galactosamine and N-acetyl-d-glucosamine. However, the linkage between repeat units in NIPH 70 was d...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Shashkov, A. S., Kenyon, J. J., Senchenkova, S. N., Shneider, M. M., Popova, A. V., Arbatsky, N. P., Miroshnikov, K. A., Volozhantsev, N. V., Hall, R. M., Knirel, Y. A. Tags: Microbial Biology Source Type: research
Biochemical characterization of an {alpha}1,2-colitosyltransferase from Escherichia coli O55:H7
In this study, starting with chemically prepared colitose, 94.6 mg of GDP-colitose was prepared via a facile and efficient one-pot two-enzyme system involving an l-fucokinase/GDP-l-Fuc pyrophosphorylase and an inorganic pyrophosphatase (EcPpA). WbgN, a putative ColT from E. coli O55:H5 was then cloned, overexpressed, purified and biochemically characterized by using GDP-colitose as a sugar donor. Activity assay and structural identification of the synthetic product clearly demonstrated that wbgN encodes an α1,2-ColT. Biophysical study showed that WbgN does not require metal ion, and is highly active at pH 7.5–9...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Wu, Z., Zhao, G., Li, T., Qu, J., Guan, W., Wang, J., Ma, C., Li, X., Zhao, W., Wang, P. G., Li, L. Tags: Glycan Synthesis Source Type: research
Comparison of biological activities of human antithrombins with high-mannose or complex-type nonfucosylated N-linked oligosaccharides
The structure of the N-linked oligosaccharides attached to antithrombin (AT) has been shown to affect its anticoagulant activity and pharmacokinetics. Human AT has biantennary complex-type oligosaccharides with the unique feature of lacking a core fucose, which affects its biological activities by changing its heparin-binding affinity. In human plasma, AT circulates as a mixture of the α-form bearing four oligosaccharides and the β-form lacking an oligosaccharide at Asn135. However, it remains unclear how the immature high-mannose-type oligosaccharides produced by mammalian cells affect biological activities of ...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Yamada, T., Kanda, Y., Takayama, M., Hashimoto, A., Sugihara, T., Satoh-Kubota, A., Suzuki-Takanami, E., Yano, K., Iida, S., Satoh, M. Tags: Glycan Recognition Source Type: research
Urinary {beta}-galactosidase stimulates Ca2+ transport by stabilizing TRPV5 at the plasma membrane
Transcellular Ca2+ transport in the late distal convoluted tubule and connecting tubule (DCT2/CNT) of the kidney is a finely controlled process mediated by the transient receptor potential vanilloid type 5 (TRPV5) channel. A complex-type-N-glycan bound at the extracellular residue Asn358 of TRPV5 through post-translational glycosylation has been postulated to regulate the activity of TRPV5 channels. Using in vitro Ca2+ transport assays, immunoblot analysis, immunohistochemistry, patch clamp electrophysiology and total internal reflection fluorescence microscopy, it is demonstrated that the glycosidase β-galactosidase ...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Leunissen, E. H. P., Blanchard, M. G., Sheedfar, F., Lavrijsen, M., van der Wijst, J., Bindels, R. J. M., Hoenderop, J. G. J. Tags: Glycan Recognition Source Type: research
Elevated level of serum glycoprotein bifucosylation and prognostic value in Chinese breast cancer
Aberrant glycosylation is highly associated with cancer progression. The aim of this study was to compare bifucosylated N-glycans in sera obtained from healthy controls and breast cancer patients, with the goal of identifying a potential indicator for monitoring the recurrence and metastasis of breast cancer. A unique structural pattern of bifucosylated N-glycan, with both core and antennary fucosylation, was identified in breast cancer patients. The spectrum of antennary fucosylation was a composite of the standard spectra of Lewis X and H2, indicating a mixture of the two epitopes. Permethylated N-glycans of the glycopro...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Ju, L., Wang, Y., Xie, Q., Xu, X., Li, Y., Chen, Z., Li, Y. Tags: Cancer Biology Source Type: research
Structure and biological activity of a fucosylated chondroitin sulfate from the sea cucumber Cucumaria japonica
A fucosylated chondroitin sulfate (FCS) was isolated from the body wall of Pacific sea cucumber Cucumaria japonica by extraction in the presence of papain followed by Cetavlon precipitation and anion-exchange chromatography. FCS was shown to contain d-GalNAc, d-GlcA, l-Fuc and sulfate in molar proportions of about 1:1:1:4.5. Structure of FCS was elucidated using NMR spectroscopy and methylation analysis of the native polysaccharide and products of its desulfation and carboxyl reduction. The polysaccharide was shown to contain a typical chondroitin core ->3)-β-d-GalNAc-(1->4)-β-d-GlcA-(1->. Sulfate groups...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Ustyuzhanina, N. E., Bilan, M. I., Dmitrenok, A. S., Shashkov, A. S., Kusaykin, M. I., Stonik, V. A., Nifantiev, N. E., Usov, A. I. Tags: Analytical Glycobiology Source Type: research
Diverse molecular recognition properties of blood group A binding monoclonal antibodies
Information about specificity and affinity is critical for use of carbohydrate-binding antibodies. Herein, we evaluated eight monoclonal antibodies to the blood group A (BG-A) antigen. Antibodies 87-G, 9A, HE-10, HE-24, HE-193, HE-195, T36 and Z2A were profiled on a glycan microarray to assess specificity, relative affinity and the influence of glycan density on recognition. Our studies highlight several noteworthy recognition properties. First, most antibodies bound GalNAcα1–3Gal and the BG-A trisaccharide nearly as well as larger BG-A oligosaccharides. Second, several antibodies only bound the BG-A trisacchar...
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Gildersleeve, J. C., Wright, W. S. Tags: Glycan Recognition Source Type: research
Apiose: one of nature's witty games
Apiose is a unique branched-chain pentose found principally in plants. It is a key component of structurally complex cell wall polysaccharides, as well as being present in a large number of naturally occurring secondary metabolites. This review provides a comprehensive overview of the current state of knowledge on the metabolism and natural occurrence of apiose, using cyanogenic glycosides and their related compounds as a case study. The biological function of apiose and of apiosylated compounds is discussed. (Source: Glycobiology)
Source: Glycobiology - March 29, 2016 Category: Biology Authors: Picmanova, M., Moller, B. L. Tags: REVIEW Source Type: research
Novel or reproducible: That is the question
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Source: Glycobiology - March 29, 2016 Category: Biology Authors: Ten Hagen, K. G. Tags: GLYCO-FORUM Source Type: research
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Source: Glycobiology - March 29, 2016 Category: Biology Tags: GLYCO-FORUM Source Type: research
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Source: Glycobiology - March 29, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
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Source: Glycobiology - March 29, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
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Source: Glycobiology - March 29, 2016 Category: Biology Tags: Cover/Standing Material Source Type: research
