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V N Sukhorukov, V P Karagodin, E R Zakiev, A N Orekhov
This review mainly focuses on the medical and biological role of relatively poor studied enzymes known as sialidases. Structure and function of sialic acid, particularly as a component of gangliosides and plasma lipoproteins is described. Among the whole variety of sialidases, trans-sialidase is of special interest, since it is capable of removing sialic acid from the low density lipoprotein (LDL) particles and transferring it to different acceptors in plasma. Desialylation of LDL in turn endow them the capacity to accumulate in the smooth muscle cells of human aortic intima, highlighting the important role of desialylation in atherogenesis...
October 19, 2016: Current Pharmaceutical Design
Wenjie Gao, Henghui Li, Yanyan Liu, Yuhong Liu, Xiaojun Feng, Bi-Feng Liu, Xin Liu
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has become an important technology for glycan analysis due to its ease of operation, short analysis time and impurity tolerance. However, the low ionization efficiency of N-glycans led to the difficulty in analyzing glycans of low abundance in complex biological samples due to the lack of basic site for protonation. Therefore, highly sensitive method for the glycans analysis is in urgent demand. Here we report a new strategy to introduce a permanent charge at the reducing end of N-linked glycans by a one pot reaction, where glycosylamines that were obtained by rapid deglycosylation within 5min were labeled with N-succinimidyloxycarbonylmethyl tris (2,4,6- trimethoxyphenyl) phosphonium bromide (TMPP-Ac-OSu)...
December 1, 2016: Talanta
Pavel Damborský, Katarzyna M Koczula, Andrea Gallotta, Jaroslav Katrlík
Lateral flow assays (LFAs) enable the simple and rapid detection and quantification of analytes and is popular for point-of-care (PoC), point-of-use and outdoor testing applications. LFAs typically depend on antibody or nucleic acid based recognition. We present the innovative concept of a LFA using lectins in the role of the biorecognition element. Lectins are a special kind of glycan-binding protein and the lectin-based LFA herein described was developed for the determination of the glycosylation of free prostate specific antigen (PSA)...
October 21, 2016: Analyst
Alexandre Guillot, Manuel Dauchez, Nicolas Belloy, Jessica Jonquet, Laurent Duca, Beatrice Romier, Pascal Maurice, Laurent Debelle, Laurent Martiny, Vincent Durlach, Stephanie Baud, Sebastien Blaise
Sialic acids (SA) are monosaccharides that can be located at the terminal position of glycan chains on a wide range of proteins. The post-translational modifications, such as N-glycan chains, are fundamental to protein functions. Indeed, the hydrolysis of SA by specific enzymes such as neuraminidases can lead to drastic modifications of protein behavior. However, the relationship between desialylation of N-glycan chains and possible alterations of receptor function remains unexplored. Thus, the aim of the present study is to establish the impact of SA removal from N-glycan chains on their conformational behavior...
October 19, 2016: Scientific Reports
Zhigang Wu, Yunpeng Liu, Cheng Ma, Lei Li, Jing Bai, Lauren Byrd-Leotis, Yi Lasanajak, Yuxi Guo, Liuqing Wen, He Zhu, Jing Song, Yanhong Li, David A Steinhauer, David F Smith, Baohua Zhao, Xi Chen, Wanyi Guan, Peng George Wang
Glycans play diverse roles in a wide range of biological processes. Research on glycan-binding events is essential for learning their biological and pathological functions. However, the functions of terminal and internal glycan epitopes exhibited during binding with glycan-binding proteins (GBPs) and/or viruses need to be further identified. Therefore, a focused library of 36 biantennary asparagine (Asn)-linked glycans with some presenting tandem glycan epitopes was synthesized via a combined Core Isolation/Enzymatic Extension (CIEE) and one-pot multienzyme (OPME) synthetic strategy...
October 18, 2016: Organic & Biomolecular Chemistry
Lorena Claumarchirant, Luis Manuel Sanchez-Siles, Esther Matencio, Amparo Alegria, María Jesús Lagarda
Sialic acid (Sia) contents and bioaccessibility (BA) in human milk (HM) and infant formulas (IFs) were determined, and Sia intakes by infants between 0-6 months of age were evaluated. Total Sia contents in HM decreased during lactation from 136.14 to 24.47 mg/100 mL. The total Sia contents in IFs (13.15-25.78 mg/100 mL) were lower than in HM, and were not related to the addition of ingredients acting as sources of Sia in their formulation. The Sia intakes derived from IFs consumption were lower than in HM, and only one IF reached the intakes provided by HM from the age of two months...
October 18, 2016: Journal of Agricultural and Food Chemistry
Freek Cox, Ted Kwaks, Boerries Brandenburg, Martin H Koldijk, Vincent Klaren, Bastiaan Smal, Hans J W M Korse, Eric Geelen, Lisanne Tettero, David Zuijdgeest, Esther J M Stoop, Eirikur Saeland, Ronald Vogels, Robert H E Friesen, Wouter Koudstaal, Jaap Goudsmit
Interactions with receptors for the Fc region of IgG (FcγRs) have been shown to contribute to the in vivo protection against influenza A viruses provided by broadly neutralizing antibodies (bnAbs) that bind to the viral hemagglutinin (HA) stem. In particular, Fc-mediated antibody-dependent cellular cytotoxicity (ADCC) has been shown to contribute to protection by stem-binding bnAbs. Fc-mediated effector functions appear not to contribute to protection provided by strain-specific HA head-binding antibodies...
2016: Frontiers in Immunology
Stephanie Holst, Gabi W van Pelt, Wilma E Mesker, Rob A Tollenaar, Ana I Belo, Irma van Die, Yoann Rombouts, Manfred Wuhrer
The current protocols for glycomic analysis of cells often require a large quantity of material (5-20 million cells). In order to analyze the N-glycosylation from small amounts of cells (≤1 million) as obtained from, for example, primary cell lines or cell sorting, and in a higher throughput approach, we set up a robust 96-well format PVDF-membrane based N-glycan release protocol followed by linkage-specific sialic acid stabilization, cleanup, and MALDI-TOF-MS analysis. We further evaluated the influence of PNGase F incubation time on the N-glycan profile...
2017: Methods in Molecular Biology
Shiyue Zhou, Kerry M Wooding, Yehia Mechref
The development of a reliable and high-throughput glycomic profiling strategy is in high demand due to the biological roles of glycans and their association with different diseases. Native analysis can be quite difficult because of the low ionization efficiency and microheterogeneity of glycans. In this chapter, the sample preparation protocols and LC-MS analysis of permethylated glycan strategies are introduced. Solid-phase permethylation is a fast, convenient, and high-yield method to stabilize sialic acid and improve glycan ionization efficiency and analysis in positive mode; this results in a more sensitive and reliable glycomic profiling strategy...
2017: Methods in Molecular Biology
Noortje de Haan, Karli R Reiding, Manfred Wuhrer
Matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) is a highly suitable method for the rapid analysis of IgG glycopeptides, providing a wealth of structural information. A limitation of this approach is that it generates a bias when analyzing sialylated species due to the labile nature of sialic acid glycosidic linkages. One way to overcome this problem is by chemical derivatization of the sialic acids. The method presented here results in both the stabilization of the sialic acids, as well as the differentiation of α2,3- and α2,6-linked sialic acids by mass...
2017: Methods in Molecular Biology
Hai Yu, Yanhong Li, Jie Zeng, Vireak Thon, Dung M Nguyen, Thao Ly, Hui Yu Kuang, Alice Ngo, Xi Chen
Glycosphingolipids are a diverse family of biologically important glycolipids. In addition to variations on the lipid component, more than 300 glycosphingolipid glycans have been characterized. These glycans are directly involved in various molecular recognition events. Several naturally occurring sialic acid forms have been found in sialic acid-containing glycosphingolipids, namely gangliosides. However, ganglioside glycans containing less common sialic acid forms are currently not available. Herein, highly effective one-pot multienzyme (OPME) systems are used in sequential for high-yield and cost-effective production of glycosphingolipid glycans, including those containing different sialic acid forms such as N-acetylneuraminic acid (Neu5Ac), N-glycolylneuraminic acid (Neu5Gc), 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (Kdn), and 8-O-methyl-N-acetylneuraminic acid (Neu5Ac8OMe)...
October 13, 2016: Journal of Organic Chemistry
Jamie M O'Sullivan, Sonia Aguila, Emily McRae, Soracha E Ward, Orla Rawley, Padraic G Fallon, Teresa M Brophy, Roger J S Preston, Lauren Brady, Orla Sheils, Alain Chion, James S O'Donnell
BACKGROUND: Enhanced von Willebrand factor (VWF) clearance is important in the etiology of both type 1 and type 2 von Willebrand disease (VWD). In addition, previous studies have demonstrated that VWF glycans play a key role in regulating in vivo clearance. However, the molecular mechanisms underlying VWF clearance remain poorly understood. OBJECTIVE: To define the molecular mechanisms through which VWF N-glycan structures influence in vivo clearance. METHODS: Using a series of exoglycosidases, different pd-VWF glycoforms were generated...
October 12, 2016: Journal of Thrombosis and Haemostasis: JTH
Johanna M U Silvola, Helena Virtanen, Riikka Siitonen, Sanna Hellberg, Heidi Liljenbäck, Olli Metsälä, Mia Ståhle, Tiina Saanijoki, Meeri Käkelä, Harri Hakovirta, Seppo Ylä-Herttuala, Pekka Saukko, Matti Jauhiainen, Tibor Z Veres, Sirpa Jalkanen, Juhani Knuuti, Antti Saraste, Anne Roivainen
Given the important role of inflammation and the potential association of the leukocyte trafficking-associated adhesion molecule vascular adhesion protein 1 (VAP-1) with atherosclerosis, this study examined whether functional VAP-1 is expressed in atherosclerotic lesions and, if so, whether it could be targeted by positron emission tomography (PET). First, immunohistochemistry revealed that VAP-1 localized to endothelial cells of intra-plaque neovessels in human carotid endarterectomy samples from patients with recent ischemic symptoms...
October 12, 2016: Scientific Reports
Maheswata Sahoo, Lingaraja Jena, Surya Narayan Rath, Satish Kumar
The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1...
September 2016: Genomics & Informatics
Li Hui Wu, Xiao Ting Shao, Jun Xia Guo, Hui Sun, Qi Chen, Jing Pan, Qian Qian Cai, Yi Wei Dong, Zhong Yi Chen, Xiao Mei Yan, Min Peng, Nanbert Zhong, Xing Zhong Wu
Sialic acid modification is a kind of post-translational modification. To investigate the regulation effect of sialic acid on neural differentiation, we used CycloManN propanyl perac (CycloManN pro), a metabolic precursor of sialic acid, to treat PC12 cells. We noted that CycloManN pro indeed robustly promoted global sialylation detected by MAL II lectin blot in PC12 cells. Simultaneously, we interestingly found that the neurite outgrowth of PC12 cells was significantly promoted by the CycloManN pro treatment...
October 10, 2016: Glycoconjugate Journal
Tadanobu Takahashi, Saori Unuma, Sawako Kawagishi, Yuuki Kurebayashi, Maiko Takano, Hiroki Yoshino, Akira Minami, Takashi Yamanaka, Tadamune Otsubo, Kiyoshi Ikeda, Takashi Suzuki
Most equine influenza A viruses (IAVs) show strong binding to glycoconjugates containing N-glycolylneuraminic acid (Neu5Gc) as well as N-acetylneuraminic acid (Neu5Ac). Therefore, the progeny of equine IAV is thought to be released from the infected cell surface through removal of sialic acids by the viral sialidase. In the present study, equine IAV sialidases showed significantly lower substrate affinity than that of human IAV sialidases to artificial and natural Neu5Gc-conjugated substrates. The substrate specificity of equine IAV sialidases is in disagreement with their binding specificity to molecular species of sialic acid...
2016: Biological & Pharmaceutical Bulletin
Gnanesh Kumar B S, Avadhesha Surolia
Seeds of Maackia amurensis constitutes two sialic acid specific agglutinins known as leukagglutinin and hemagglutinin. Maackia amurensis leukagglutinin (MAL) recognizes α2-3-linked sialic acid present mainly in N-glycans and composed of two disulfide linked monomers. It exhibits potential N-glycosylation sites (four PNGs) which have been assumed to undergo differential occupancy. In this study we have characterized the site specific macro- and microheterogeneity of monomers in detail by analysing N-glycopeptides and peptides through liquid chromatography coupled to ion trap mass spectrometer in MS(3) mode (LC-MS(n))...
October 5, 2016: International Journal of Biological Macromolecules
Rohan Yadav, Shani Leviatan Ben-Arye, Balamurugan Subramani, Vered Padler-Karavani, Raghavendra Kikkeri
Sialic acids (Sias) are important terminal sugars on cell surfaces involved in a wide range of protein-carbohydrate interactions. Hence, agents modulating sias-mediated protein interactions are promising inhibitors or vaccine candidates. Here, we report the synthesis of Neu5Acα(2-6)Gal structural analogs and their binding to a series of siglecs. The results showed distinct binding patterns with conserved siglecs (hCD22 and mCD22) compared to rapid evolving siglecs (Siglecs -3 & -10).
September 27, 2016: Organic & Biomolecular Chemistry
Toshi Horie, Megumi Inomata, Takeshi Into, Yoshiaki Hasegawa, Noriyuki Kitai, Fuminobu Yoshimura, Yukitaka Murakami
Bacterial glycoproteins are associated with physiological and pathogenic functions of bacteria. It remains unclear whether bacterial glycoproteins can bind to specific classes of lectins expressed on host cells. Tannerella forsythia is a gram-negative oral anaerobe that contributes to the development of periodontitis. In this study, we aimed to find lectin-binding glycoproteins in T. forsythia. We performed affinity chromatography of wheat germ agglutinin, which binds to N-acetylglucosamine (GlcNAc) and sialic acid (Sia), and identified OmpA-like protein as the glycoprotein that has the highest affinity...
2016: PloS One
Junko Nio-Kobayashi, Hazirah B Z Abidin, Jeremy K Brown, Toshihiko Iwanaga, Andrew W Horne, W Colin Duncan
Sialylation creates a negative charge on the cell surface that can interfere with blastocyst implantation. For example, α2,6-sialylation on terminal galactose, catalyzed by the sialyltransferase ST6GAL1, inhibits the binding of galectin-1, a β-galactoside-binding lectin. We recently reported the potential involvement of galectin-1 and -3 in the pathogenesis of tubal ectopic pregnancy; however, the precise role of galectins and their ligand glycoconjugates remain unclear. Here, we investigated the expression of the genes encoding α2,3- and α2,6-galactoside sialyltransferases (ST3GAL1 - 6 and ST6GAL1 - 2) and the localization of sialic acids in the Fallopian tube of women with or without ectopic implantation...
October 5, 2016: Molecular Reproduction and Development
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