scholarly journals Immunization of rabbits with synthetic peptides derived from a highly conserved β-sheet epitope region underneath the receptor binding site of influenza A virus

2013 ◽  
pp. 233
Author(s):  
Shoji Ideno ◽  
Kaoru Sakai ◽  
Mikihiro Yunoki ◽  
Ritsuko Kubota-Koketsu ◽  
Yuji Inoue ◽  
...  
Keyword(s):  
Binding Site ◽  
Influenza A Virus ◽  
Receptor Binding ◽  
Synthetic Peptides ◽  
Influenza A ◽  
Beta Sheet ◽  
Receptor Binding Site ◽  
Epitope Region

scholarly journals Potent sialic acid inhibitors that target influenza A virus hemagglutinin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu-Jen Chang ◽  
Cheng-Yun Yeh ◽  
Ju-Chien Cheng ◽  
Yu-Qi Huang ◽  
Kai-Cheng Hsu ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Antiviral Activity ◽  
Binding Site ◽  
Influenza A Virus ◽  
Receptor Binding ◽  
Influenza A ◽  
The United States ◽  
Ligand Complex ◽  
Receptor Binding Site ◽  
Computational Strategy

AbstractEradicating influenza A virus (IAV) is difficult, due to its genetic drift and reassortment ability. As the infectious cycle is initiated by the influenza glycoprotein, hemagglutinin (HA), which mediates the binding of virions to terminal sialic acids moieties, HA is a tempting target of anti-influenza inhibitors. However, the complexity of the HA structure has prevented delineation of the structural characterization of the HA protein–ligand complex. Our computational strategy efficiently analyzed > 200,000 records of compounds held in the United States National Cancer Institute (NCI) database and identified potential HA inhibitors, by modeling the sialic acid (SA) receptor binding site (RBS) for the HA structure. Our modeling revealed that compound NSC85561 showed significant antiviral activity against the IAV H1N1 strain with EC50 values ranging from 2.31 to 2.53 µM and negligible cytotoxicity (CC50 > 700 µM). Using the NSC85561 compound as the template to generate 12 derivatives, robust bioassay results revealed the strongest antiviral efficacies with NSC47715 and NSC7223. Virtual screening clearly identified three SA receptor binding site inhibitors that were successfully validated in experimental data. Thus, our computational strategy has identified SA receptor binding site inhibitors against HA that show IAV-associated antiviral activity.

scholarly journals Novel Mutations Evading Avian Immunity around the Receptor Binding Site of the Clade 2.3.2.1c Hemagglutinin Gene Reduce Viral Thermostability and Mammalian Pathogenicity

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 923 ◽  
Author(s):  
An ◽  
Lee ◽  
Hong ◽  
Song ◽  
Kim ◽  
...  
Keyword(s):  
Binding Site ◽  
Receptor Binding ◽  
Mammalian Cells ◽  
Influenza A ◽  
Receptor Binding Site ◽  
Receptor Affinity ◽  
Replication Efficiency ◽  
Adaptive Mutations ◽  
H5n1 Avian Influenza ◽  
Clade 2.3.2.1C

Abstract: Since 2007, highly pathogenic clade 2.3.2 H5N1 avian influenza A (A(H5N1)) viruses have evolved to clade 2.3.2.1a, b, and c; currently only 2.3.2.1c A(H5N1) viruses circulate in wild birds and poultry. During antigenic evolution, clade 2.3.2.1a and c A(H5N1) viruses acquired both S144N and V223I mutations around the receptor binding site of hemagglutinin (HA), with S144N generating an N-glycosylation sequon. We introduced single or combined reverse mutations, N144S and/or I223V, into the HA gene of the clade 2.3.2.1c A(H5N1) virus and generated PR8-derived, 2 + 6 recombinant A(H5N1) viruses. When we compared replication efficiency in embryonated chicken eggs, mammalian cells, and mice, the recombinant virus containing both N144S and I223V mutations showed increased replication efficiency in avian and mammalian hosts and pathogenicity in mice. The N144S mutation significantly decreased avian receptor affinity and egg white inhibition, but not all mutations increased mammalian receptor affinity. Interestingly, the combined reverse mutations dramatically increased the thermostability of HA. Therefore, the adaptive mutations possibly acquired to evade avian immunity may decrease viral thermostability as well as mammalian pathogenicity.

scholarly journals Substitutions near the Hemagglutinin Receptor-Binding Site Determine the Antigenic Evolution of Influenza A H3N2 Viruses in U.S. Swine

2014 ◽  
Vol 88 (9) ◽  
pp. 4752-4763 ◽  
Author(s):  
N. S. Lewis ◽  
T. K. Anderson ◽  
P. Kitikoon ◽  
E. Skepner ◽  
D. F. Burke ◽  
...  
Keyword(s):  
Binding Site ◽  
Receptor Binding ◽  
Influenza A ◽  
Receptor Binding Site ◽  
Antigenic Evolution

scholarly journals Human erythropoietin-specific sites of monoclonal antibody-mediated neutralization

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 670-675
Author(s):  
MR Fibi ◽  
M Aslan ◽  
P Hintz-Obertreis ◽  
JU Pauly ◽  
M Gerken ◽  
...  
Keyword(s):  
Binding Site ◽  
Receptor Binding ◽  
Conformational Changes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Site ◽  
Epitope Region ◽  
Human Erythropoietin ◽  
Group A ◽  
Group B ◽  
Binding Determinants

Recombinant human erythropoietin (rhuEpo)-specific mouse monoclonal antibodies (MoAbs) have been produced and characterized. All antibodies were specifically reactive with rhuEpo in enzyme-linked immunosorbent assay (ELISA). Epitope exclusion studies showed three distinct epitope regions, A, B, and C, recognized by neutralizing MoAbs. An additional epitope region D was recognized by non-neutralizing MoAbs. Antibodies defining an epitope region competed with each other for binding sites, but did not compete with antibodies defining a different epitope region. Group B antibodies were able to compete for the receptor binding site on rhuEpo with a soluble human Epo-receptor-lg fusion protein. No single peptide sequences were found to specifically interact either with group B MoAbs or with the rhuEpo-receptor. Therefore, it is suggested that epitope region B and the receptor binding site share binding determinants that are primarily composed of conformational epitopes. Because group A and group C antibodies did not compete with the receptor for binding to the receptor binding site of the rhuEpo molecule, it is suggested that neutralization via epitope regions A and C is mediated through binding inhibition caused by conformational changes, transmuting the binding site(s) for the receptor. Conversely, binding to the receptor seems to induce conformational changes in the hormone molecule, eliminating epitopes for group A and C antibodies.

scholarly journals Human erythropoietin-specific sites of monoclonal antibody-mediated neutralization

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 670-675 ◽  
Author(s):  
MR Fibi ◽  
M Aslan ◽  
P Hintz-Obertreis ◽  
JU Pauly ◽  
M Gerken ◽  
...  
Keyword(s):  
Binding Site ◽  
Receptor Binding ◽  
Conformational Changes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Site ◽  
Epitope Region ◽  
Human Erythropoietin ◽  
Group A ◽  
Group B ◽  
Binding Determinants

Abstract Recombinant human erythropoietin (rhuEpo)-specific mouse monoclonal antibodies (MoAbs) have been produced and characterized. All antibodies were specifically reactive with rhuEpo in enzyme-linked immunosorbent assay (ELISA). Epitope exclusion studies showed three distinct epitope regions, A, B, and C, recognized by neutralizing MoAbs. An additional epitope region D was recognized by non-neutralizing MoAbs. Antibodies defining an epitope region competed with each other for binding sites, but did not compete with antibodies defining a different epitope region. Group B antibodies were able to compete for the receptor binding site on rhuEpo with a soluble human Epo-receptor-lg fusion protein. No single peptide sequences were found to specifically interact either with group B MoAbs or with the rhuEpo-receptor. Therefore, it is suggested that epitope region B and the receptor binding site share binding determinants that are primarily composed of conformational epitopes. Because group A and group C antibodies did not compete with the receptor for binding to the receptor binding site of the rhuEpo molecule, it is suggested that neutralization via epitope regions A and C is mediated through binding inhibition caused by conformational changes, transmuting the binding site(s) for the receptor. Conversely, binding to the receptor seems to induce conformational changes in the hormone molecule, eliminating epitopes for group A and C antibodies.

scholarly journals Avian Influenza A Viruses Differ from Human Viruses by Recognition of Sialyloligosaccharides and Gangliosides and by a Higher Conservation of the HA Receptor-Binding Site

Virology ◽  
1997 ◽  
Vol 233 (1) ◽  
pp. 224-234 ◽  
Author(s):  
M.N. Matrosovich ◽  
A.S. Gambaryan ◽  
S. Teneberg ◽  
V.E. Piskarev ◽  
S.S. Yamnikova ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Binding Site ◽  
Receptor Binding ◽  
Influenza A ◽  
Influenza A Viruses ◽  
Receptor Binding Site ◽  
Human Viruses

scholarly journals Role of Neuraminidase in Influenza A(H7N9) Virus Receptor Binding

2017 ◽  
Vol 91 (11) ◽  
Author(s):  
Donald J. Benton ◽  
Stephen A. Wharton ◽  
Stephen R. Martin ◽  
John W. McCauley
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Binding Site ◽  
Influenza A Virus ◽  
Receptor Binding ◽  
Influenza A ◽  
Health Concern ◽  
H7n9 Virus ◽  
Virus Receptor ◽  
Sialic Acid Receptors

ABSTRACT Influenza A(H7N9) viruses have caused a large number of zoonotic infections since their emergence in 2013. They remain a public health concern due to the repeated high levels of infection with these viruses and their perceived pandemic potential. A major factor that determines influenza A virus fitness and therefore transmissibility is the interaction of the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) with the cell surface receptor sialic acid. Typically, the HA is responsible for binding to the sialic acid to allow virus internalization and the NA is a sialidase responsible for cleaving sialic acid to aid virus spread and release. N9 NA has previously been shown to have receptor binding properties mediated by a sialic acid binding site, termed the hemadsorption (Hb) site, which is discrete from the enzymatically active sialidase site. This study investigated the N9 NA from a zoonotic H7N9 virus strain in order to determine its possible role in virus receptor binding. We demonstrate that this N9 NA has an active Hb site which binds to sialic acid, which enhances overall virus binding to sialic acid receptor analogues. We also show that the N9 NA can also contribute to receptor binding due to unusual kinetic characteristics of the sialidase site which specifically enhance binding to human-like α2,6-linked sialic acid receptors. IMPORTANCE The interaction of influenza A virus glycoproteins with cell surface receptors is a major determinant of infectivity and therefore transmissibility. Understanding these interactions is important for understanding which factors are necessary to determine pandemic potential. Influenza A viruses generally mediate binding to cell surface sialic acid receptors via the hemagglutinin (HA) glycoprotein, with the neuraminidase (NA) glycoprotein being responsible for cleaving the receptor to allow virus release. Previous studies showed that the NA proteins of the N9 subtype can bind sialic acid via a separate binding site distinct from the sialidase active site. This study demonstrates for purified protein and virus that the NA of the zoonotic H7N9 viruses has a binding capacity via both the secondary binding site and unusual kinetic properties of the sialidase site which promote receptor binding via this site and which enhance binding to human-like receptors. This could have implications for understanding human-to-human transmission of these viruses.

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