» Articles » PMID: 8546703

The Specificity of Mitochondrial Complex I for Ubiquinones

Overview
Journal Biochem J
Specialty Biochemistry
Date 1996 Jan 1
PMID 8546703
Citations 21
Authors
Affiliations
Soon will be listed here.
Abstract

We report the first detailed study on the ubiquinone (coenzyme Q; abbreviated to Q) analogue specificity of mitochondrial complex I, NADH:Q reductase, in intact submitochondrial particles. The enzymic function of complex I has been investigated using a series of analogues of Q as electron acceptor substrates for both electron transport activity and the associated generation of membrane potential. Q analogues with a saturated substituent of one to three carbons at position 6 of the 2,3-dimethoxy-5-methyl-1,4-benzoquinone ring have the fastest rates of electron transport activity, and analogues with a substituent of seven to nine carbon atoms have the highest values of association constant derived from NADH:Q reductase activity. The rate of NADH:Q reductase activity is potently but incompletely inhibited by rotenone, and the residual rotenone-insensitive rate is stimulated by Q analogues in different ways depending on the hydrophobicity of their substituent. Membrane potential measurements have been undertaken to evaluate the energetic efficiency of complex I with various Q analogues. Only hydrophobic analogues such as nonyl-Q or undecyl-Q show an efficiency of membrane potential generation equivalent to that of endogenous Q. The less hydrophobic analogues as well as the isoprenoid analogue Q-2 are more efficient as substrates for the redox activity of complex I than for membrane potential generation. Thus the hydrophilic Q analogues act also as electron sinks and interact incompletely with the physiological Q site in complex I that pumps protons and generates membrane potential.

Citing Articles

Residual Complex I activity and amphidirectional Complex II operation support glutamate catabolism through mtSLP in anoxia.

Ravasz D, Bui D, Nazarian S, Pallag G, Karnok N, Roberts J Sci Rep. 2024; 14(1):1729.

PMID: 38242919 PMC: 10798963. DOI: 10.1038/s41598-024-51365-4.


Redox-Cycling "Mitocans" as Effective New Developments in Anticancer Therapy.

Bakalova R, Lazarova D, Sumiyoshi A, Shibata S, Zhelev Z, Nikolova B Int J Mol Sci. 2023; 24(9).

PMID: 37176145 PMC: 10179378. DOI: 10.3390/ijms24098435.


Coenzyme Q Analogues: Benefits and Challenges for Therapeutics.

Suarez-Rivero J, Pastor-Maldonado C, Povea-Cabello S, Alvarez-Cordoba M, Villalon-Garcia I, Munuera-Cabeza M Antioxidants (Basel). 2021; 10(2).

PMID: 33557229 PMC: 7913973. DOI: 10.3390/antiox10020236.


Coenzyme Q is a universal substrate for the measurement of respiratory chain enzyme activities in trypanosomatids.

Cermakova P, Kovalinka T, Ferenczyova K, Horvath A Parasite. 2019; 26:17.

PMID: 30901308 PMC: 6430614. DOI: 10.1051/parasite/2019017.


CoQ supplementation rescues nephrotic syndrome through normalization of HS oxidation pathway.

Kleiner G, Barca E, Ziosi M, Emmanuele V, Xu Y, Hidalgo-Gutierrez A Biochim Biophys Acta Mol Basis Dis. 2018; 1864(11):3708-3722.

PMID: 30251690 PMC: 6181133. DOI: 10.1016/j.bbadis.2018.09.002.


References
1.
Schatz G, RACKER E . Partial resolution of the enzymes catalyzing oxidative phosphorylation. VII. Oxidative phosphorylation in the diphosphopyridine nucleotide-cytochrome b segment of the respiratory chain: assay and properties in submitochondrial particles. J Biol Chem. 1966; 241(6):1429-38. View

2.
Lenaz G, Daves Jr G, Kfolkers K . Organic structural specificity and sites of coenzyme Q in succinoxidase and DPNH-oxidase systems. Arch Biochem Biophys. 1968; 123(3):539-50. DOI: 10.1016/0003-9861(68)90175-6. View

3.
Horgan D, Ohno H, SINGER T . Studies on the respiratory chain-linked reduced nicotinamide adenine dinucleotide dehydrogenase. XV. Interactions of piericidin with the mitochondrial respiratory chain. J Biol Chem. 1968; 243(22):5967-76. View

4.
Ernster L, Lee I, Norling B, Persson B . Studies with ubiquinone-depleted submitochondrial particles. Essentiality of ubiquinone for the interaction of succinate dehydrogenase, NADH dehydrogenase, and cytochrome b. Eur J Biochem. 1969; 9(3):299-310. DOI: 10.1111/j.1432-1033.1969.tb00609.x. View

5.
Gutman M, SINGER T, Casida J . Studies on the respiratory chain-linked reduced nicotinamide adenine dinucleotide dehydrogenase. XVII. Reaction sites of piericidin A and rotenone. J Biol Chem. 1970; 245(8):1992-7. View