© 2006 The Japanese Biochemical Society.
Regular Paper |
Theoretical Study on Charge-Transfer Interaction between Acyl-CoA Dehydrogenase and 3-Thiaacyl-CoA Using Density Functional Method
1 Department of Biosystems Science, Graduate School of Science and Technology, Kobe University, 1-1 Rokodai-cho, Nada-ku, Kobe 657-8501; and Departments of 2 Molecular Enzymology and 3 Molecular Physiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556
* To whom correspondence should be addressed. Phone/Fax: +81-89-946-9587, E-mail: putaro{at}protein.osaka-u.ac.jp (T.Tanaka); Phone: +81-96-373-5063, Fax: +81-96-373-5066, E-mail: harr{at}gpo.kumamoto-u.ac.jp (H.Tamaoki).
Acyl-CoA dehydrogenase forms a complex with a substrate analog, 3-thiaacyl-CoA, exhibiting a charge-transfer (CT) band. The structure of a complex model of oxidized lumiflavin with deprotonated 3-thiabutanoate ethylthioester designed for the above CT complex was fully optimized by means of density functional theory (DFT), the spatial arrangement being similar to the corresponding X-ray structure reported previously. The electrostatic interaction between flavin and an anionic ligand, therefore, plays a major role in determination of the arrangement of the CT complex. When the excitation energies and oscillator strengths for the optimized structures of complex models including oxidized 8-substituted lumiflavins were calculated, the obtained wavelengths correlated well with observed values reported. Subsequently, we carried out DFT calculations for new complex models redesigned for complexes of oxidized 8-substituted FADs with an anionic ligand by introducing hydrogen bonds at the carbonyl group of the ligand with the 2'-hydroxyl group of the N10-ribityl of FAD and with the main-chain amide group of Glu376. The CT absorbing wavelengths of the new complex models exhibited better correlation with those observed previously. Consequently, comparison of substituent effects on the DFT calculations for the complex models will lead to a deeper understanding of the CT interaction and the effect of the hydrogen-bonding interaction on the CT framework.
Present address: Integrated Center for Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  Y. Nishina, K. Sato, H. Tamaoki, C. Setoyama, R. Miura, and K. Shiga FT-IR Spectroscopic Studies on the Molecular Mechanism for Substrate Specificity/Activation of Medium-Chain Acyl-CoA Dehydrogenase J. Biochem., September 1, 2009; 146(3): 351 - 357. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Nishina, K. Sato, C. Setoyama, H. Tamaoki, R. Miura, and K. Shiga Intramolecular and Intermolecular Perturbation on Electronic State of FAD Free in Solution and Bound to Flavoproteins: FTIR Spectroscopic Study by Using the C = O Stretching Vibrations as Probes J. Biochem., August 1, 2007; 142(2): 265 - 272. [Abstract] [Full Text] [PDF]
|
|