scholarly journals Role of Secondary Sialic Acid Binding Sites in Influenza N1 Neuraminidase

2010 ◽  
Vol 132 (9) ◽  
pp. 2883-2885 ◽  
Author(s):  
Jeffrey C. Sung ◽  
Adam W. Van Wynsberghe ◽  
Rommie E. Amaro ◽  
Wilfred W. Li ◽  
J. Andrew McCammon
Keyword(s):  
Sialic Acid ◽  
Binding Sites ◽  
Sialic Acid Binding

scholarly journals Sperm Binding to Oviductal Epithelial Cells in the Rat: Role of Sialic Acid Residues on the Epithelial Surface and Sialic Acid-Binding Sites on the Sperm Surface1

2004 ◽  
Vol 71 (4) ◽  
pp. 1262-1269 ◽  
Author(s):  
Paula P. Cortés ◽  
Pedro A. Orihuela ◽  
Lidia M. Zúñiga ◽  
Luis A. Velásquez ◽  
Horacio B. Croxatto
Keyword(s):  
Sialic Acid ◽  
Epithelial Cells ◽  
Binding Sites ◽  
Epithelial Surface ◽  
Sperm Binding ◽  
Sialic Acid Binding

scholarly journals Role of Sialic Acid Binding Specificity of the 1918 Influenza Virus Hemagglutinin Protein in Virulence and Pathogenesis for Mice

2009 ◽  
Vol 83 (8) ◽  
pp. 3754-3761 ◽  
Author(s):  
Li Qi ◽  
John C. Kash ◽  
Vivien G. Dugan ◽  
Ruixue Wang ◽  
Guozhong Jin ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Sialic Acid ◽  
Influenza A ◽  
Influenza Pandemic ◽  
Binding Specificity ◽  
Influenza Viruses ◽  
Virulence Determinants ◽  
Sialic Acid Binding ◽  
1918 Influenza

ABSTRACT The 1918 influenza pandemic caused more than 40 million deaths and likely resulted from the introduction and adaptation of a novel avian-like virus. Influenza A virus hemagglutinins are important in host switching and virulence. Avian-adapted influenza virus hemagglutinins bind sialic acid receptors linked via α2-3 glycosidic bonds, while human-adapted hemagglutinins bind α2-6 receptors. Sequence analysis of 1918 isolates showed hemagglutinin genes with α2-6 or mixed α2-6/α2-3 binding. To characterize the role of the sialic acid binding specificity of the 1918 hemagglutinin, we evaluated in mice chimeric influenza viruses expressing wild-type and mutant hemagglutinin genes from avian and 1918 strains with differing receptor specificities. Viruses expressing 1918 hemagglutinin possessing either α2-6, α2-3, or α2-3/α2-6 sialic acid specificity were fatal to mice, with similar pathology and cellular tropism. Changing α2-3 to α2-6 binding specificity did not increase the lethality of an avian-adapted hemagglutinin. Thus, the 1918 hemagglutinin contains murine virulence determinants independent of receptor binding specificity.

scholarly journals The structure of siglec-7 in complex with sialosides: leads for rational structure-based inhibitor design

2006 ◽  
Vol 397 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Helen Attrill ◽  
Hirokazu Takazawa ◽  
Simone Witt ◽  
Soerge Kelm ◽  
Rainer Isecke ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Binding Sites ◽  
Cellular Interactions ◽  
Inhibitor Design ◽  
Binding Assays ◽  
Rational Structure ◽  
Transmembrane Receptors ◽  
Acetylneuraminic Acid ◽  
Sialic Acid Binding ◽  
Inhibition Data

Siglecs (sialic acid binding Ig-like lectins) are transmembrane receptors for sialylated glycoconjugates that modulate cellular interactions and signalling events in the haematopoietic, immune and nervous systems. Siglec-7 is a structural prototype for the recently described family of immune inhibitory CD33-related siglecs and is predominantly expressed on natural killer cells and monocytes, as well as subsets of CD8 T-cells. Siglec-specific inhibitors are desired for the detection of masked and unmasked forms of siglecs, to aid in dissection of signalling pathways and as tools to investigate siglecs as potential therapeutic targets. As a first step towards this end, we present the crystal structure of siglec-7 in complex with a sialylated ligand, the ganglioside analogue DSLc4 [α(2,3)/α(2,6) disialyl lactotetraosyl 2-(trimethylsilyl)ethyl], which allows for a detailed description of the binding site, required for structure-guided inhibitor design. Mutagenesis and binding assays were used to demonstrate a key structural role for Lys131, a residue that changes conformation upon sialic acid binding. Differences between the binding sites of siglec family members were then exploited using α-methyl Neu5Ac (N-acetylneuraminic acid) as a basic scaffold. A co-crystal of siglec-7 in complex with the sialoside inhibitor, oxamido-Neu5Ac [methyl α-9-(amino-oxalyl-amino)-9-deoxy-Neu5Ac] and inhibition data for the sialosides gives clear leads for future inhibitor design.

scholarly journals The Role of Sialic Acids in the Establishment of Infections by Pathogens, With Special Focus on Leishmania

2021 ◽  
Vol 11 ◽  
Author(s):  
Tainá Cavalcante ◽  
Mariana Medina Medeiros ◽  
Simon Ngao Mule ◽  
Giuseppe Palmisano ◽  
Beatriz Simonsen Stolf
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Host Cell ◽  
Functional Diversity ◽  
Sialic Acids ◽  
Cellular Communication ◽  
Special Focus ◽  
Functional Studies ◽  
Sialic Acid Binding

Carbohydrates or glycans are ubiquitous components of the cell surface which play crucial biological and structural roles. Sialic acids (Sias) are nine-carbon atoms sugars usually present as terminal residues of glycoproteins and glycolipids on the cell surface or secreted. They have important roles in cellular communication and also in infection and survival of pathogens. More than 20 pathogens can synthesize or capture Sias from their hosts and incorporate them into their own glycoconjugates and derivatives. Sialylation of pathogens’ glycoconjugates may be crucial for survival inside the host for numerous reasons. The role of Sias in protozoa such as Trypanosoma and Leishmania was demonstrated in previous studies. This review highlights the importance of Sias in several pathogenic infections, focusing on Leishmania. We describe in detail the contributions of Sias, Siglecs (sialic acid binding Ig-like lectins) and Neuraminidase 1 (NEU 1) in the course of Leishmania infection. A detailed view on the structural and functional diversity of Leishmania-related Sias and host-cell receptors will be provided, as well as the results of functional studies performed with different Leishmania species.

scholarly journals Research progress on the role of sialic acid-binding immunoglobulin-like lectin 9 in various diseases

2021 ◽  
Vol 5 (2.1) ◽  
pp. 51
Author(s):  
Ling Cao ◽  
Xiaoliang Yuan
Keyword(s):  
Sialic Acid ◽  
Autoimmune Diseases ◽  
Inflammatory Cytokines ◽  
Immune Cells ◽  
Immune Escape ◽  
Research Progress ◽  
Tumor Immune Escape ◽  
Sialic Acid Binding ◽  
Pro Inflammatory Cytokines

Sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9) is a receptor that expresses on the surface of immune cells. It plays an important role in the body’s immune response. Increased expression of Siglec-9 has been reported in infectious diseases, autoimmune diseases and cancer. Pathogenic microorganism and tumor cells can inhibit the recognition and killing of immune cells by upregulating their own specific sialic acid and binding with Siglec-9 on the surface of host immune cells, and suppress the release of pro-inflammatory cytokines and promote the release of anti-inflammatory cytokines, eventually leading to immunosuppression, tumor immune escape and the like. However, the immunosuppressive function of Siglec-9 may be advantageous for diseases such as neutrophil asthma and autoimmune diseases. Therefore, further research on the mechanism of action of Siglec-9 is of great significance.

scholarly journals Evidence for involvement of IgA1 hinge glycopeptide in the IgA1-IgA1 interaction in IgA nephropathy.

1997 ◽  
Vol 8 (6) ◽  
pp. 915-919 ◽  
Author(s):  
T Kokubo ◽  
Y Hiki ◽  
H Iwase ◽  
A Horii ◽  
A Tanaka ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Iga Nephropathy ◽  
Binding Sites ◽  
Competitive Inhibition ◽  
Hinge Region ◽  
Percent Inhibition ◽  
The Core ◽  
Proline Rich Peptide ◽  
Inhibition Curve

The study was performed to investigate the role of the IgA1 hinge region in the IgA1-IgA1 interaction, which was observed previously in IgA nephropathy. The competitive inhibition assays of the IgA1-IgA1 binding were performed using the following candidates for inhibitors: native IgA1 hinge glycopeptide (nHGP), IgA1, IgA2, and IgG. The IgA1-IgA1 binding was definitely inhibited by the nHGP and the IgA1 (maximum of percent inhibition: 66.1 and 60.5%, respectively). There was no obvious inhibition in the IgA2 and the IgG. The inhibition curves of the nHGP and the IgA1 were significantly different from that of the IgG (P < 0.01, respectively). Furthermore, to reveal the detailed binding sites in the interaction, the same inhibition assays were performed using the following substances composing the IgA1 hinge glycopeptide: galactose (Gal), N-acetyl-galactosamine (GalNAc), Gal beta 1-3GalNAc, sialic acid, tetrapeptide PTPS, and synthesized hinge proline-rich peptide PVPSTPPTPSPSTPPTPSPS (sHP). sHP, Gal beta 1-3GalNAc, Gal, and GalNAc inhibited the binding (69.3, 34.1, 14.9, 14.6%, respectively). No obvious inhibition was observed in sialic acid and tetrapeptide PTPS. The inhibition curve of sHP was significantly different from that of the PTPS (P < 0.05). Those of Gal beta 1-3GalNAc, Gal, and GalNAc were also significantly different from that of sialic acid (P < 0.05, respectively). These results suggested that the IgA1-IgA1 interaction could be mediated by the core structure including the peptide and the sugars, except for sialic acid in the hinge region, resulting in the formation of the circulating macromolecular IgA1 in IgA nephropathy.

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