Amino Acid Substitutions in Loop BC and Helix C Affect Antigenic Properties of Helix D in Hybrid IFN-<i>α</i>21a/<i>α</i>2c Molecules

Schmeisser, Hana; Hu, Renqiu; Kontsek, Peter; Bekisz, Joseph; Zoon, Kathryn C.

doi:10.1089/10799900252952253

Cited by 2 publications

(1 citation statement)

References 32 publications

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“…Finally, we chose to dock the loop in the SD1 subdomain of IFNAR1 enclosing the 64G12 epitope with IFN residues located at the C-terminal of helix D (Figure 6). This is in agreement with Schmeisser et al, (41) who showed that amino acid substitutions in loop BC, helix C, and helix D alter the interaction between IFN-R and its receptor and influence the threshold of activation of the biological response.…”

Section: Ifnar1 Residues Involved In Interferon Bindingsupporting

confidence: 92%

Identification of Residues of the IFNAR1 Chain of the Type I Human Interferon Receptor Critical for Ligand Binding and Biological Activity

et al. 2004

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The antiviral and antiproliferative activities of human type I interferons (IFNs) are mediated by two transmembrane receptor subunits, IFNAR1 and IFNAR2. To elucidate the role of IFNAR1 in IFN binding and the establishment of biological activity, specific residues of IFNAR1 were mutated. Residues (62)FSSLKLNVY(70) of the S5-S6 loop of the N-terminal subdomain of IFNAR1 and tryptophan-129 of the second subdomain of IFNAR1 were shown to be crucial for IFN-alpha binding and signaling and establishment of biological activity. Mutagenesis of peptide (278)LRV in the third subdomain shows that these residues are critical for IFN-alpha-induced biological activity but not for ligand binding. These data, together with the sequence homology of IFNAR1 with cytokine receptors of known structure and the recently resolved NMR structure of IFNAR2, led to the establishment of a three-dimensional model of the human IFN-alpha/IFNAR1/IFNAR2 complex. This model predicts that following binding of IFN to IFNAR1 and IFNAR2 the receptor complex assumes a "closed form", in which the N-terminal domain of IFNAR1 acts as a lid, resulting in the activation of intracellular kinases. Differences in the primary sequence of individual IFN-alpha subtypes and resulting differences in binding affinity, duration of ligand/receptor association, or both would explain differences in intracellular signal intensities and biological activity observed for individual IFN-alpha subtypes.

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Section: Ifnar1 Residues Involved In Interferon Bindingsupporting

confidence: 92%

Identification of Residues of the IFNAR1 Chain of the Type I Human Interferon Receptor Critical for Ligand Binding and Biological Activity

et al. 2004

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Binding Characteristics of IFN-αSubvariants to IFNAR2-EC and Influence of the 6-Histidine Tag

Schmeisser

Kontsek

Esposito

et al. 2006

Journal of Interferon & Cytokine Research

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The expression, purification, detection, and assay of recombinant proteins have been made more convenient and rapid by the use of small affinity tags. To facilitate the purification of interferon-alpha2c (IFN-alpha2c) by metal chelate affinity chromatography, N-terminal 6-histidine tag was introduced via genetic manipulation. Two preparations of IFN material were purified; one contained IFN-alpha2c with the 6-histidine tag, and the other contained IFN-alpha2c without the 6-histidine tag. The antigenic properties of the human IFN-alpha2c subvariant with and without the 6-histidine tag, as well as the effects of the N-terminal 6-histidine tag on IFN-alpha2c interaction with the extracellular domain of human IFN-alpha receptor chain 2 (IFNAR2-EC) were examined. For the purposes of this study, IFNs were characterized by Western blots with anti-IFN monoclonal antibodies (mAb) and bioassays. Immunoblot analyses showed differences between IFN-alpha2c-6-histidine tag and IFN-alpha2a, b, c in their interaction with IFNAR2-EC. We also observed differences between IFN-alpha2c-6-histidine tag and IFN-alpha2a, b, c in bioactivities. This study is the first report that shows that an N-terminal 6-histidine tag on IFN-alpha2c can affect its interaction with receptor and cause a different bioactivity.

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Amino Acid Substitutions in Loop BC and Helix C Affect Antigenic Properties of Helix D in Hybrid IFN-α21a/α2c Molecules

Cited by 2 publications

References 32 publications

Identification of Residues of the IFNAR1 Chain of the Type I Human Interferon Receptor Critical for Ligand Binding and Biological Activity

Identification of Residues of the IFNAR1 Chain of the Type I Human Interferon Receptor Critical for Ligand Binding and Biological Activity

Binding Characteristics of IFN-αSubvariants to IFNAR2-EC and Influence of the 6-Histidine Tag

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