A high diffusion coefficient for coenzyme Q10 might be related to a folded structure

FEBS Letters

Lenaz, Giorgio¹  Casadio, Rita²  Di Bernardo, Salvatore¹  Fato, Romana¹  Fariselli, Piero² 

[1] Laboratory of Bioenergetics, Department of Biochemistry `G. Moruzzi', via Irnerio 48, University of Bologna, 40126 Bologna, Italy;Laboratory of Biophysics, Department of Biology, via Irnerio 42, University of Bologna, 40126 Bologna, Italy

关键词: Coenzyme Q;    Molecular dynamics;    Phospholipid vesicle;    Diffusion;    Fluorescence quenching;   

DOI  :  10.1016/S0014-5793(98)00313-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We measured the lateral diffusion of different coenzyme Q homologues and analogues in model lipid vesicles using the fluorescence collisional quenching technique with pyrene derivatives and found diffusion coefficients in the range of 10⁻⁶ cm²/s. Theoretical diffusion coefficients for these highly hydrophobic components were calculated according to the free volume theory. An important parameter in the free volume theory is the relative dimension between diffusant and solvent: a molecular dynamics computer simulation of the coenzymes yielded their most probable geometries and volumes and revealed surprisingly similar sizes of the short and long homologues, due to a folded structure of the isoprenoid chain in the latter, with a length for coenzyme Q₁₀ of 21 Å. Using this information we were able to calculate diffusion coefficients in the range of 10⁻⁶ cm²/s, in good agreement with those found experimentally.

【 授权许可】

Unknown