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Validating the Acetylcholine Binding Protein's Conversion Potential to a Human Nicotinic Acetylcholine Receptor.
Author(s) -
Nemecz Ákos,
Taylor Palmer
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.579.1
Subject(s) - homomeric , nicotinic acetylcholine receptor , epibatidine , methyllycaconitine , ligand gated ion channel , chemistry , acetylcholine receptor , nicotinic agonist , protein subunit , cys loop receptors , ion channel , ligand (biochemistry) , biophysics , biochemistry , receptor , biology , gene
The cys‐loop family of ligand‐gated ion channels plays an important role in the chemical‐to‐electrical transduction of neuronal signaling. The well‐studied homomeric α7‐nAChR may be linked to nicotine addiction, and shows possible genetic linkages to such diseases as Alzheimer's and schizophrenia. The discovery of a homologous soluble snail acetylcholine binding protein (AChBP), also homomeric, provided a structural surrogate of the extracellular ligand‐binding domain; however, the binding protein, despite the requisite ligand properties, shows only ~30% residue identity with members of the nicotinic receptor family. We generated systematic mutations of the soluble Aplysia californica to achieve sequences resembling α7‐nAChR at the subunit interfaces and analyzed ligand binding affinities. Key constructs, representing stages of subunit interface conversion, were subsequently characterized using classical α7‐nAChR selective and nAChR ligands, such as peptidic antagonists α‐neurotoxin and α‐conotoxins, (+)‐epibatidine, lobeline, and methyllycaconitine and compared to values obtained on a full‐length human α7‐nAChR. Although no mutational construct fully resembles α7 selectivity, we have found a final construct with comparable α7‐nAChR affinities. Hence such constructs provide better suited templates for α7‐nAChR drug design. (Supported by: U01‐DA 019372, GM07752‐29)