2icq: Difference between revisions

[[Image:2icq.jpg|left|200px]]<br /><applet load="2icq" size="350" color="white" frame="true" align="right" spinBox="true"  

In contrast with most inhalational anesthetics, the anesthetic gases xenon (Xe) and nitrous oxide (N(2)O) act by blocking the N-methyl-d-aspartate (NMDA) receptor. Using x-ray crystallography, we examined the binding characteristics of these two gases on two soluble proteins as structural models: urate oxidase, which is a prototype of a variety of intracellular globular proteins, and annexin V, which has structural and functional characteristics that allow it to be considered as a prototype for the NMDA receptor. The structure of these proteins complexed with Xe and N(2)O were determined. One N(2)O molecule or one Xe atom binds to the same main site in both proteins. A second subsite is observed for N(2)O in each case. The gas-binding sites are always hydrophobic flexible cavities buried within the monomer. Comparison of the effects of Xe and N(2)O on urate oxidase and annexin V reveals an interesting relationship with the in vivo pharmacological effects of these gases, the ratio of the gas-binding sites' volume expansion and the ratio of the narcotic potency being similar. Given these data, we propose that alterations of cytosolic globular protein functions by general anesthetics would be responsible for the early stages of anesthesia such as amnesia and hypnosis and that additional alterations of ion-channel membrane receptor functions are required for deeper effects that progress to "surgical" anesthesia.

2ICQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_flavus Aspergillus flavus] with <scene name='pdbligand=ACE:'>ACE</scene>, <scene name='pdbligand=AZA:'>AZA</scene>, <scene name='pdbligand=CYS:'>CYS</scene> and <scene name='pdbligand=N2O:'>N2O</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Urate_oxidase Urate oxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.3.3 1.7.3.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ICQ OCA].  

[[Category: Abraini, J H.]]

[[Category: Santos, J Sopkova-de Oliveira.]]

[[Category: h, N Colloc.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:51:20 2008''