3P106 Structural biological study of reaction intermediates of heme oxygenase
3P106 ヘムオキシゲナーゼの反応中間体の構造生物学的研究(ヘム蛋白質))

M. Unno, M. Ikeda-Saito
2005 Seibutsu Butsuri  
The CO depende 皿t activatien mechanism of a transcriptiona ユfactor CooA Areaction mechaniSm of a nitric crXide reductase , cytochrome P450nor( P450nor ) 丘om Fusariu 皿 axysporu 皿 , was cLarified by usr ing Dens1ty fu皿 ctk )nal thcory and Hartree −Fc〕ck calcUlations . In this reaction meChanism , moleculal o 【bital ( MQ ) analysis reve 団ed that the NO ligalld dissociates from the heme iron immediately after one electron reduction by NADH , and MO enelgy ana ユ ysiS 【 evea ユ ed 七hat NADH acts as a
more » ... hat NADH acts as a one − eleCt :on reducer , not as a tw 〔 卜 electron reducer , and that NADH has a pivotal role different from other one − el tron reducer8 . The Iole of NADH is to act a8 a doub! e oneelectron donor ( Le・ , one − eleCtloll transfer occulli 皿 g twice ) and tO co 皿 bh亘e with the NO − molecnle by charge recombination ieactien . Our quantum chem . ical calculations indicated that 訓 reactions occurring in the heme pocket are too f 細t to become 匸at } limiting . Thereft 〕rel the rate limitin9 steps 血 the proposed reaction m han m ale 七he process ef capt 血 g NO and NADH int。 the heme peckat and the pr。cess 。f ex − pe旺ing a ploduct generated in the heme podket 、 Kinetics o 正these pro − cesses was discussed based on largeamplitude Vibration , which helps capturing E皿 d expe 山皿 g processes in a widely opened heme pocket of P450nor , The reaction mechanism proμ )sed here well explains pub 臨 hed experiment 国 data . 1く. Tsukamoto and Y . Akiyama : Hartree− FoCk ε皿 d DFT calcUlations f{}rthe reaction medh 肛 直8m of nitric aXide reductase cytOdlrome
doi:10.2142/biophys.45.s230_2 fatcat:sj2qtfhojndn3bljqjgzqrokiy