Fatty acids stimulate activity and restore respiratory control in a proton channel mutant of cytochromecoxidase

Changes in the respiratory control index (RCI) and ADP:O ratio were found to be related to alterations in the free fatty acids levels of rat liver mitochondria aging in 0.25 M sucrose–Tris buffer at 0 °C. Free fatty acid levels increased with time after isolation of mitochondria while a concomitant decrease in the RCI and ADP:O ratio occurred. The changes in free fatty acid levels corresponded with the reported increasing levels of phospholipase A activity in aged mitochondrial preparations. Washing these mitochondria with sucrose buffer containing 1% defatted bovine serum albumin (BSA) counteracted the aging effect on the RCI (e.g., 2.5 to 3.5) and reduced the free fatty acid levels (e.g., 50 to 16 nmol/mg protein). This reversible phenomenon could be repeated several times during the in vitro aging at 0 °C. Use of 125I-iodinated BSA showed that approximately 5 μg BSA/mg mitochondria was adsorbed by the mitochondrial membranes during washing. These results indicate a direct correlation between the level of endogenous fatty acids and the uncoupling of mitochondrial oxidative phosphorylation. The mechanism of counteracting the aging effect by BSA involves the removal of some of the free fatty acids.

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The effect of non-esterified fatty acids on the proton-pumping cytochrome c oxidase reconstituted into liposomes

Biochemical Journal ◽

10.1042/bj2540139 ◽

1988 ◽

Vol 254 (1) ◽

pp. 139-145 ◽

Cited By ~ 27

Author(s):

N Labonia ◽

M Müller ◽

A Azzi

Keyword(s):

Fatty Acids ◽

Cytochrome C ◽

Cytochrome C Oxidase ◽

Respiratory Control ◽

Proton Pumping ◽

Phospholipid Vesicles ◽

Proton Permeability ◽

Enzyme Preparations ◽

Esterified Fatty Acids ◽

Subunit Iii

Bovine heart cytochrome c oxidase was reconstituted in phospholipid vesicles, and the effect of different non-esterified fatty acids (NEFA) was studied on its proton pump and on the proton permeability of the vesicles. Neither parameter appeared to be affected by concentrations of NEFA known to uncouple oxidative phosphorylation (10 microM). Also the permeability for K+ was not affected by them. The fatty acids caused an increase in the rate of electron transfer in the absence, but not in the presence, of uncoupler and/or valinomycin [diminution of the respiratory-control index (RCI)]. The RCI of 8.7-7.5 was decreased to about 4.5 in the presence of 0.27-10 microM-NEFA. Oleic acid was not effective at the above concentrations. Subunit III-depleted enzyme preparations gave vesicles with an RCI of about 5.5, which was decreased to 4.5 in the presence of NEFA. With both native and subunit III-depleted oxidase the RCI was never decreased to the value of 1 by NEFA, as happens with classical protonophores.

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VARIATIONS IN LIPID INTAKE AND THEIR INFLUENCE ON RESPIRATION AND TRICARBOXYLIC ACID CYCLE ACTIVITY

Canadian Journal of Biochemistry ◽

10.1139/o65-175 ◽

1965 ◽

Vol 43 (9) ◽

pp. 1575-1587 ◽

Cited By ~ 5

Author(s):

Hector F. DeLuca

Keyword(s):

Fatty Acids ◽

Vitamin D ◽

Vitamin A ◽

Tricarboxylic Acid Cycle ◽

Essential Fatty Acids ◽

Respiratory Control ◽

Liver Mitochondria ◽

Tricarboxylic Acid ◽

Membrane Systems ◽

Acid Cycle

The possible role of dietary lipids and lipid-soluble constituents in the tricarboxylic acid cycle, respiratory systems, and mitochondrial structure is discussed, with special emphasis on vitamin D, vitamin A, and essential fatty acids. Deficiency of any of these substances produces structural alterations in isolated kidney or liver mitochondria. In the case of vitamin D deficiency the structural alteration in kidney mitochondria is accompanied by an increased rate of citrate and isocitrate oxidation and a decreased transfer of calcium ions from inside to outside the mitochondria. Vitamin D added in vitro or given to the intact rat specifically decreases citrate oxidation and increases the translocation of calcium. Vitamin A deficiency increases the respiration of liver homogenates and mitochondria in the absence of phosphate acceptor, an effect which could readily be reversed within 48 hours after vitamin A administration. Increased ATPase and decreased respiratory control were also noted in liver mitochondria from vitamin A deficient rats. The structural change as well as the biochemical lesions could also be reversed within 48 hours after vitamin A administration. Similar experiments with essential fatty acid deficient mitochondria also revealed a high ATPase, low respiratory control, and marked structural damage. These changes could be reversed by the feeding of essential fatty acids to the deficient animals for 1–3 weeks. Despite many attempts, it was not possible to demonstrate structural changes in mitochondria in situ as a result of any of the deficiencies described. It is suggested that the respiratory and tricarboxylic acid cycle changes that have been attributed to the lipid constituents of the diet are secondary to alterations in subcellular membrane systems. The use of these membrane systems as tools or models in a study of the mechanism of action of the dietary lipid and lipid-soluble materials is discussed.

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Calorie Restriction Maintains Mitochondrial Function and Redox Balance Avoiding Lipidomic Reprogramming during Isoproterenol-Induced Cardiac Hypertrophy

10.1101/2021.07.13.452233 ◽

2021 ◽

Author(s):

Cícera Edna Barbosa David ◽

Aline Maria Brito Lucas ◽

Pedro Lourenzo Oliveira Cunha ◽

Yuana Ivia Ponte Viana ◽

Marcos Yukio Yoshinaga ◽

...

Keyword(s):

Fatty Acids ◽

Cardiac Hypertrophy ◽

Calorie Restriction ◽

Mitochondrial Function ◽

Cardiac Tissue ◽

Unsaturated Fatty Acids ◽

Saturated Fatty Acids ◽

Respiratory Control ◽

H2o2 Production

Cardiac hypertrophy induces a metabolic shift, leading to a preferential consumption of glucose (over fatty acids) to support the high energetic demand. Typically, health cardiac tissue utilizes more fat than any other organ. Calorie restriction is a dietary procedure that induces health benefits and lifespan extension in many organisms. Given the beneficial effects of calorie restriction and the metabolic dysregulation seen during cardiac hypertrophy, we hypothesized that calorie restriction prevents cardiac hypertrophy, lipid, mitochondrial, and redox dysregulations. Strikingly, calorie restriction reversed isoproterenol-induced cardiac hypertrophy, lowered succinate driven mitochondrial H2O2 production, improved mitochondrial function (indicated as a higher Respiratory Control Ratio – RCR) and avoided mitochondrial superoxide dismutase (MnSOD) and glutathione peroxidase (GPX) repression. To gain insight into how calorie restriction could interfere with the metabolic changes induced by cardiac hypertrophy, we performed lipidomic profiling. Calorie restriction protected against the consumption of several triglycerides (TG) linked to unsaturated fatty acids, and the accumulation of TGs containing saturated fatty acids observed in hypertrophic samples. Cardiac hypertrophy induced an increase in ceramides, phosphoethanolamines and acylcarnitines (12:0, 14:0, 16:0 and 18:0) that were also reversed by calorie restriction. Altogether, our data demonstrate that hypertrophy changes the cardiac lipidome, causes mitochondrial disturbances and oxidative stress. All these changes are prevented by calorie restriction intervention in vivo. This study uncovers calorie restriction as a resource protect cardiac tissue and prevent cardiac hypertrophy-induced lipidomic remodeling.

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A history of UCPI

Biochemical Society Transactions ◽

10.1042/bst0290751 ◽

2001 ◽

Vol 29 (6) ◽

pp. 751-755 ◽

Cited By ~ 71

Author(s):

D. G. Nicholls

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Uncoupling Protein ◽

Respiratory Control ◽

Receptor Activation ◽

Protonmotive Force ◽

Acid Activation ◽

Outer Face ◽

Purine Nucleotides ◽

Brown Adipose

Interest in the enormous thermogenic capacity of brown adipose tissue (BAT) began in the 1960s and focused on BAT mitochondria (BATM), which when prepared by conventional techniques respired rapidly but displayed no respiratory control. Two apparently distinct treatments, fatty acid removal and purine nucleotide addition, induced respiratory control. In 1972, we found that BATM were highly permeant to halides and protons, and that albumin decreased the proton conductance while purine nucleotides decreased both. Devising techniques to quantify the proton leak in respiring mitochondria we found a nucleotide-sensitive conductance pathway whose ‘break-point’, the protonmotive force at which conductance suddenly increased, could be subtly modulated by free fatty acids. The nucleotide-binding site on the outer face of the inner membrane was characterized and identified by photoaffinity labelling as a 32 kDa ‘uncoupling protein’, now UCP1. Studies with intact brown adipocytes generated the currently accepted model, namely that fatty acids liberated by β3-adrenergic receptor activation act as both self-regulating second messengers for UCP1 and substrates for fatty acid activation and oxidation. Fatty acid concentration increases at the outset of thermogenesis, binding to UCP1 lowers the protonmotive force below that giving respiratory control and rapid thermogenesis proceeds. At the termination of receptor activation oxidation of residual fatty acid ‘recouples’ the mitochondria. The challenge with the novel UCPs is to demonstrate a similar coherent mechanism.

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Influence of non-esterified fatty acids on respiratory control of reconstituted cytochrome-c oxidase

FEBS Letters ◽

10.1016/0014-5793(89)81469-3 ◽

1989 ◽

Vol 251 (1-2) ◽

pp. 270-274 ◽

Cited By ~ 14

Author(s):

Carsten Thiel ◽

Bernhard Kadenbach

Keyword(s):

Fatty Acids ◽

Cytochrome C ◽

Cytochrome C Oxidase ◽

Respiratory Control ◽

Esterified Fatty Acids

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Fatty acids as modulators of cytochrome c oxidase in proteoliposomes

Biochemical Journal ◽

10.1042/bj3200557 ◽

1996 ◽

Vol 320 (2) ◽

pp. 557-561 ◽

Cited By ~ 7

Author(s):

Martyn SHARPE ◽

Ivano PERIN ◽

John WRIGGLESWORTH ◽

Peter NICHOLLS

Keyword(s):

Fatty Acids ◽

Enzyme Activity ◽

Oleic Acid ◽

Membrane Potential ◽

Cytochrome C ◽

Palmitic Acid ◽

Cytochrome C Oxidase ◽

Respiratory Control ◽

Similar Concentration

The control of cytochrome c oxidase turnover in proteoliposomes by membrane potential (ΔΨ) and by pH gradient (ΔpH) is probably kinetic in nature, and inhibition by valinomycin and stimulation by nigericin indicate that ΔpH exerts a greater influence than does an equivalent ΔΨ. Oleic acid at 100 µM removes all ΔΨ and ΔpH control, whereas a similar concentration of palmitic acid increases turnover but does not completely abolish control. Valinomycin acts synergistically with both fatty acids, indicating that the latter can act as H+/K+ exchangers, but neither fatty acid alone markedly affects ΔpH, showing that they cannot fully mimic nigericin. Oleate, but not palmitate, diminishes ΔΨ, and can move electrophoretically as oleate anion. Submicromolar palmitic acid concentrations partly stimulate turnover in ΔΨ- and ΔpH-controlled proteoliposomes, as reported by Labonia, Muller and Azzi [(1988) Biochem. J. 254, 130–145], which might represent a direct effect on cytochrome c oxidase. The ubiquity of fatty acids in biological membranes suggests that these substances might be responsible for limiting respiratory control and enzyme activity in vivo.

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