Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/3868
DC Field | Value | Language |
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dc.contributor.author | Srinivasan, Chandra | - |
dc.contributor.author | Toon, Jason | - |
dc.contributor.author | Amari, Louis | - |
dc.contributor.author | Abukhdeir, Abde M. | - |
dc.contributor.author | Hamm, Heidi | - |
dc.contributor.author | Geraldes, Carlos F. G. C. | - |
dc.contributor.author | Ho, Yee-Kin | - |
dc.contributor.author | Freitas, Duarte Mota de | - |
dc.date.accessioned | 2008-08-29T15:35:19Z | - |
dc.date.available | 2008-08-29T15:35:19Z | - |
dc.date.issued | 2004 | en_US |
dc.identifier.citation | Journal of Inorganic Biochemistry. 98:5 (2004) 691-701 | en_US |
dc.identifier.uri | https://hdl.handle.net/10316/3868 | - |
dc.description.abstract | Li+ is the most effective drug used to treat bipolar disorder; however, its exact mechanism of action has yet to be elucidated. One hypothesis is that Li+ competes with Mg2+ for the Mg2+ binding sites on guanine-nucleotide binding proteins (G-proteins). Using 7Li T1 relaxation measurements and fluorescence spectroscopy with the Mg2+ fluorophore furaptra, we detected Li+/Mg2+ competition in three preparations: the purified G-protein transducin (Gt), stripped rod outer segment membranes (SROS), and SROS with purified Gt reattached (ROS-T). When purified ROS-T, SROS or transducin were titrated with Li+ in the presence of fixed amounts of Mg2+, the apparent Li+ binding constant decreased due to Li+/Mg2+ competition. Whereas for SROS the competition mechanism was monophasic, for Gt, the competition was biphasic, suggesting that in Gt, Li+/Mg2+ competition occurred with different affinities for Mg2+ in two types of Mg2+ binding sites. Moreover, as [Li+] increased, the fluorescence excitation spectra of both ROS-T and Gt were blue shifted, indicating an increase in free [Mg2+] compatible with Li+ displacement of Mg2+ from two low affinity Mg2+ binding sites of Gt. Gt release from ROS-T membrane was also inhibited by Li+ addition. In summary, we found evidence of Li+/Mg2+ competition in Gt-containing preparations. | en_US |
dc.description.uri | http://www.sciencedirect.com/science/article/B6TGG-4BJ2538-2/1/c5cc8bd5992b6629aba06705e0861119 | en_US |
dc.format.mimetype | aplication/PDF | en |
dc.language.iso | eng | eng |
dc.rights | openAccess | eng |
dc.subject | Transducin | en_US |
dc.subject | G-proteins | en_US |
dc.subject | Lithium | en_US |
dc.subject | Magnesium | en_US |
dc.subject | Ionic competition | en_US |
dc.title | Competition between lithium and magnesium ions for the G-protein transducin in the guanosine 5'-diphosphate bound conformation | en_US |
dc.type | article | en_US |
dc.identifier.doi | 10.1016/j.jinorgbio.2003.12.023 | - |
uc.controloAutoridade | Sim | - |
item.openairetype | article | - |
item.languageiso639-1 | en | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | Com Texto completo | - |
crisitem.author.researchunit | CQC - Coimbra Chemistry Centre | - |
crisitem.author.parentresearchunit | Faculty of Sciences and Technology | - |
crisitem.author.orcid | 0000-0002-0837-8329 | - |
Appears in Collections: | FCTUC Ciências da Vida - Artigos em Revistas Internacionais |
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file796b25b80e904ded93a39f490e7a6d3c.pdf | 330.39 kB | Adobe PDF | View/Open |
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