Spatial Structure and Activity of Synthetic Fragments of Lynx1 and of Nicotinic Receptor Loop C Models
| Autor: | Igor E. Kasheverov, Konstantin S. Mineev, Alexey V. Feofanov, Dmitry A. Senko, Maxim N. Zhmak, Victor I. Tsetlin, Alexander S. Arseniev, Natalia S. Egorova, Anastasia A. Ignatova, Yuri N. Utkin, Elena V. Kryukova, Igor Ivanov |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Models Molecular Circular dichroism Stereochemistry Neurotoxins lcsh:QR1-502 Peptide Receptors Nicotinic Ligands Biochemistry lcsh:Microbiology Article law.invention radioligand assay 03 medical and health sciences Acetylcholine binding 0302 clinical medicine Bacterial Proteins law Animals Humans Receptor Molecular Biology Acetylcholine receptor Adaptor Proteins Signal Transducing Lymnaea chemistry.chemical_classification Binding Sites peptide fragments spatial structure Bungarotoxins Radioligand Assay circular dichroism nuclear magnetic resonance 030104 developmental biology Nicotinic agonist chemistry three-finger proteins nicotinic acetylcholine receptors Protein Conformation beta-Strand Carrier Proteins Peptides 030217 neurology & neurosurgery Torpedo Protein Binding |
| Zdroj: | Biomolecules Volume 11 Issue 1 Biomolecules, Vol 11, Iss 1, p 1 (2021) |
| ISSN: | 2218-273X |
| Popis: | Lynx1, membrane-bound protein co-localized with the nicotinic acetylcholine receptors (nAChRs) and regulates their function, is a three-finger protein (TFP) made of three &beta structural loops, similarly to snake venom &alpha neurotoxin TFPs. Since the central loop II of &alpha neurotoxins is involved in binding to nAChRs, we have recently synthesized the fragments of Lynx1 central loop, including those with the disulfide between Cys residues introduced at N- and C-termini, some of them inhibiting muscle-type nAChR similarly to the whole-size water-soluble Lynx1 (ws-Lynx1). Literature shows that the main fragment interacting with TFPs is the C-loop of both nAChRs and acetylcholine binding proteins (AChBPs) while some ligand-binding capacity is preserved by analogs of this loop, for example, by high-affinity peptide HAP. Here we analyzed the structural organization of these peptide models of ligands and receptors and its role in binding. Thus, fragments of Lynx1 loop II, loop C from the Lymnaea stagnalis AChBP and HAP were synthesized in linear and Cys-cyclized forms and structurally (CD and NMR) and functionally (radioligand assay on Torpedo nAChR) characterized. Connecting the C- and N-termini by disulfide in the ws-Lynx1 fragment stabilized its conformation which became similar to the loop II within the 1H-NMR structure of ws-Lynx1, the activity being higher than for starting linear fragment but lower than for peptide with free cysteines. Introduced disulfides did not considerably change the structure of HAP and of loop C fragments, the former preserving high affinity for &alpha bungarotoxin, while, surprisingly, no binding was detected with loop C and its analogs. |
| Databáze: | OpenAIRE |
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