Direct Modulation of Microtubule Stability Contributes to Anthracene General Anesthesia

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• 作者：Daniel J. Emerson ; Brian P. Weiser ; John Psonis ; Zhengzheng Liao ; Olena Taratula ; Ashley Fiamengo ; Xiaozhao Wang ; Keizo Sugasawa ; Amos B. Smith ; III ; Roderic G. Eckenhoff ; Ivan J. Dmochowski
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：April 10, 2013
• 年：2013
• 卷：135
• 期：14
• 页码：5389-5398
• 全文大小：506K
• 年卷期：v.135,no.14(April 10, 2013)
• ISSN：1520-5126

文摘

Recently, we identified 1-aminoanthracene as a fluorescent general anesthetic. To investigate the mechanism of action, a photoactive analogue, 1-azidoanthracene, was synthesized. Administration of 1-azidoanthracene to albino stage 40鈥?7 tadpoles was found to immobilize animals upon near-UV irradiation of the forebrain region. The immobilization was often reversible, but it was characterized by a longer duration consistent with covalent attachment of the ligand to functionally important targets. IEF/SDS-PAGE examination of irradiated tadpole brain homogenate revealed labeled protein, identified by mass spectrometry as 尾-tubulin. In vitro assays with aminoanthracene-cross-linked tubulin indicated inhibition of microtubule polymerization, similar to colchicine. Tandem mass spectrometry confirmed anthracene binding near the colchicine site. Stage 40鈥?7 tadpoles were also incubated 1 h with microtubule stabilizing agents, epothilone D or discodermolide, followed by dosing with 1-aminoanthracene. The effective concentration of 1-aminoanthracene required to immobilize the tadpoles was significantly increased in the presence of either microtubule stabilizing agent. Epothilone D similarly mitigated the effects of a clinical neurosteroid general anesthetic, allopregnanolone, believed to occupy the colchicine site in tubulin. We conclude that neuronal microtubules are 鈥渙n-pathway鈥?targets for anthracene general anesthetics and may also represent functional targets for some neurosteroid general anesthetics.