Ubiquinone diffusion rate

Range 0.3 - 100 (see comments and method) µm^2/sec
Organism Unspecified
Reference Lenaz G, Fato R. Is ubiquinone diffusion rate-limiting for electron transfer? J Bioenerg Biomembr. 1986 Oct18(5):369-401. p.384 paragraph 4PubMed ID3021715
Primary Source 1) Fato R, Battino M, Degli Esposti M, Parenti Castelli G, Lenaz G. Determination of partition and lateral diffusion coefficients of ubiquinones by fluorescence quenching of n-(9-anthroyloxy)stearic acids in phospholipid vesicles and mitochondrial membranes. Biochemistry. 1986 Jun 3 25(11):3378-90. AND (2) Gupte S, Wu ES, Hoechli L, Hoechli M, Jacobson K, Sowers AE, Hackenbrock CR. Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components. Proc Natl Acad Sci U S A. 1984 May81(9):2606-10.PubMed ID3730366, 6326133
Method Using fluorescence quenching corresponding to a diffusion coefficient in the range of 10^–6 cm^2/sec (primary source (1)) the long-range diffusion of a short-chain polar Q derivative measured by fluorescence photobleaching recovery (FRAP) (primary source (2)) is 3×10^–9 cm^2/sec.
Comments The discrepancy between these results is carefully scrutinized, and is mainly ascribed to the differences in diffusion ranges measured by the two techniques it is proposed that short-range diffusion, measured by fluorescence quenching, is more meaningful for electron transfer than long-range diffusion measured by FRAP
Entered by Ron Milo - Admin
ID 100805