کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5814085 | 1556622 | 2015 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Engineered α4β2 nicotinic acetylcholine receptors as models for measuring agonist binding and effect at the orthosteric low-affinity α4-α4 interface
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کلمات کلیدی
nAChRdpmSBCCRRCys-loop receptorACh - آهRadioligand binding - اتصال دهنده رادیولینگAcetylcholine - استیل کولینElectrophysiology - الکتروفیزیولوژیdisintegrations per minute - تخریب در دقیقهPharmacology - فارماکولوژی یا داروشناسیwild-type - نوع وحشیIon channel - کانال یونیNicotinic acetylcholine receptor (nAChR) - گیرنده استیل کولین نیکوتین (nAChR)nicotinic acetylcholine receptor - گیرنده استیلکولین نیکوتین
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب رفتاری
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The nicotinic acetylcholine receptor α4β2 is important for normal mammalian brain function and is known to express in two different stoichiometries, (α4)2(β2)3 and (α4)3(β2)2. While these are similar in many aspects, the (α4)3(β2)2 stoichiometry differs by harboring a third orthosteric acetylcholine binding site located at the α4-α4 interface. Interestingly, the third binding site has, so far, only been documented using electrophysiological assays, actual binding affinities of nicotinic receptor ligands to this site are not known. The present study was therefore aimed at determining binding affinities of nicotinic ligands to the α4-α4 interface. Given that epibatidine shows large functional potency differences at α4-β2 vs. α4-α4 interfaces, biphasic binding properties would be expected at (α4)3(β2)2 receptors. However, standard saturation binding experiments with [3H]epibatidine did not reveal biphasic binding under the conditions utilized. Therefore, an engineered β2 construct (β2HQT), which converts the β(â) face to resemble that of an α4(â) face, was utilized to create (α4)3(β2HQT)2 receptors harboring three α4-α4 interfaces. With this receptor, low affinity binding of epibatidine with a Kd of â¼5 nM was observed in sharp contrast to a Kd value of â¼10 pM observed for wild-type receptors. A strong correlation between binding affinities at the (α4)3(β2HQT)2 receptor and functional potencies at the wild-type receptor of a range of nicotinic ligands highlighted the validity of using the mutational approach. Finally, large differences in activities at α4-β2 vs. α4-α4 interfaces were observed for structurally related agonists underscoring the need for establishing all binding parameters of compounds at α4β2 receptors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuropharmacology - Volume 92, May 2015, Pages 135-145
Journal: Neuropharmacology - Volume 92, May 2015, Pages 135-145
نویسندگان
Philip K. Ahring, Jeppe A. Olsen, Elsebet Ã. Nielsen, Dan Peters, Martin H.F. Pedersen, Line A. Rohde, Jette S. Kastrup, Azadeh Shahsavar, Dinesh C. Indurthi, Mary Chebib, Michael Gajhede, Thomas Balle,