Fourier transform infrared (FTIR) spectroscopic investigation of the nicotinic acetylcholine receptor (nAChR) Investigation of agonist binding and receptor conformational changes by flash‐induced release of ‘caged’ carbamoylcholine

FEBS Letters

Hucho, Ferdinand¹  Mäntele, Werner³  Naumann, Dieter²  Barth, Andreas³  Görne-Tschelnokow, Ute¹ 

[1] Institute für Biochemie, Freie Universität Berlin, Thielallee 63, 1000 Berlin 33, Germany;Robert-Koch-Institut des Budesgesund-heitamts, Nordufer 20, 1000 Berlin 65, Germany;Institut für Biophysics und Strahlenbiologie der Universität Freiburg, Freiburg, Germany

关键词: Nicotinic acetylcholine receptor (nAChR);    Conformational change;    Agonist binding;    FTIR;    FTIR;    Fourier-transform infrared;    AChR;    nicotinic acetylcholine receptor;    ACh;    acetylcholine;    cage I;    N-[1-(2-nitrophenyl)ethyl]carbamoylcholine iodide;    cage II;    N-(α-carboxy-2-nitrobenzyl)carbamoylcholine trifluoroacetate;   

DOI  :  10.1016/0014-5793(92)81097-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The binding and interaction of carbamoylcholine with the nicotinic acetylcholine receptor was investigated using photolytically release carbamoylcholine (‘caged’ carbamoylcholine). Upon UV flash activation of this photolabile substrate analog, characteristic changes in the IR absorbance spectrum were detected. Apart from difference bands arising from the changes of molecular structure upon photolytical release, spectral features can be attributed to the agonist upon binding to the receptor as well as to conformational changes of the receptor itself. The two photo-labile agonist analogs N-[1-(2-nitrophenyl)ethyl] carbamoylcholine iodide (cage I) and N-(α-carboxy-2-nitrobenzyl) carbamoylcholine trifluoroacetate (cage II), with different structures for comparison of the 1680-1540 cm⁻¹ region sensitive for protein conformation, yielded consistent results. A preliminary interpretation in terms of substrate binding and local conformational changes of the receptor upon carbamoylcholine binding is provided, in analogy to the binding of acetylcholine, activation, and subsequent deactivation taking place during signal transduction.

【 授权许可】

Unknown