Evidence for an in vivo modification of mitochondrial proteins by coenzyme A

Huth, Walter; Worm-Breitgoff, Claudia; Möller, Ulrike; Wunderlich, Ilona

doi:10.1016/0167-4838(91)90518-5

Cited by 10 publications

(20 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Evidence has been reported of the existence of a form of CoA that is tightly bound to mitochondrial proteins and is released by treatment with DTT or ␤-mercaptoethanol (52,53). In their studies, the authors noted significant selectivity in the proteins to which the CoASH was bound, apparently through the reversible formation of disulfide bonds, and they reported partial inhibition of the activities of the CoA-bound forms of the enzymes acetyl-CoA acetyltransferase and 3-oxoacyl-CoA thiolase.…”

Section: Hyperoxia and Lung Coash And Coassgmentioning

confidence: 95%

CoASH and CoASSG Levels in Lungs of Hyperoxic Rats as Potential Biomarkers of Intramitochondrial Oxidant Stresses

O'Donovan

Rogers

Kelley³

et al. 2002

Pediatr Res

View full text Add to dashboard Cite

Coenzyme A (CoASH) is compartmentalized preferentially in the mitochondria, and CoASH and its mixed disulfide with glutathione (CoASSG) undergo thiol/disulfide exchange reactions with glutathione (GSH) and glutathione disulfide (GSSG) in vitro. We measured CoASH and CoASSG in freeze-clamped lung tissues from Fischer-344 and Sprague-Dawley rats maintained in room air or exposed to Ͼ95% O 2 for 48 h to test the hypothesis that oxidant stresses on lung thiol status would be observed in the CoASH/CoASSG redox couple, suggesting oxidant stress responses in the mitochondria. Lung tissue concentrations of CoASSG in the Fischer-344 rats declined from 0.89 Ϯ 0.15 to 0.51 Ϯ 0.13 nmol/g of lung after 48 h of hyperoxia. CoASH levels declined from 6.40 Ϯ 0.84 to 3.0 Ϯ 0.65 nmol/g of lung, and acetyl CoA levels also were lower in the lungs of animals exposed to hyperoxia. CoASH/CoASSG ratios were lower in animals exposed to hyperoxia, satisfying our previously defined criteria for an oxidant stress on this thiol/disulfide redox couple, but absolute CoASSG levels were not increased, as would be expected for oxidant stresses driven simply by increases in reactive oxygen species or other oxidants. Pulmonary edema was observed in the hyperoxic rats and accounted for some of the declines in CoASH concentrations, but CoASH contents per total lung also declined. Lung mitochondrial succinate dehydrogenase activities were not diminished in rats exposed to hyperoxia, indicating that the decreases in CoASH concentrations are not attributable to general destruction of lung mitochondria. Lung GSSG contents were greater in the hyperoxia animals, but GSH/GSSG ratios, which are dominated by extramitochondrial pools, did not decrease in these animals. The mechanisms responsible for, and the possible pathophysiologic consequences of, the decreases in lung CoASH concentrations are not evident from the data available at the present time, but the loss of more than half the tissue contents of CoASH is likely to generate additional metabolic effects that could have significant pathophysiologic consequences. Administration of supplemental oxygen remains an important therapy in the care of patients with pulmonary insufficiency, as is encountered in many prematurely born infants or in adults with acute respiratory distress. However, this supplemental oxygen can cause adverse effects, as has been observed in the lungs of experimental animals and humans exposed to elevated oxygen tensions (1-4). Cellular injury is manifested when the rates of generation of the reactive species are increased beyond the capacities of the antioxidant defense mechanisms, such as with exposure to hyperoxia (1,5,6), or when the functions of the antioxidant defense mechanisms are deficient, compromised, or developmentally unprepared, such as in prematurely born infants (3,7,8).In the course of exposure of experimental animals to Ͼ95% oxygen, a relatively prolonged period usually is observed in

show abstract

Section: Hyperoxia and Lung Coash And Coassgmentioning

confidence: 95%

CoASH and CoASSG Levels in Lungs of Hyperoxic Rats as Potential Biomarkers of Intramitochondrial Oxidant Stresses

O'Donovan

Rogers

Kelley³

et al. 2002

Pediatr Res

View full text Add to dashboard Cite

show abstract

“…The administration in i o of [1-"%C]pantothenic acid, the precursor of CoA, resulted in the radioactive labelling of several mitochondrial matrix proteins [8]. This radioactivity derived from [1-"%C]pantothenic acid could be attributed to proteinbound CoA or acyl-CoA.…”

Section: Introductionmentioning

confidence: 99%

“…The mitochondrial pellet was washed and resuspended in the abovementioned isolation medium but containing 30 % (v\v) Percoll and centrifuged for 10 min at 17 369 g. The supernatant was removed and the mitochondrial pellet was resuspended in the isolation medium containing in addition 1 mM PMSF, 1 mM EDTA, 1 µg\ml pepstatin and 1 µg\ml leupeptin. Mitoplasts and the mitochondrial matrix fraction were prepared using digitonin (1.2 mg\10 mg of protein) and Lubrol Wx (2 mg\10 mg of protein) as described by Schnaitman and Greenawalt [12] and as modified by Huth et al [8]. The matrix protein fraction was stabilized by addition of 50 mM potassium phosphate buffer (pH 7.2) and 20 % (w\v) glycerol.…”

Section: Isolation Of Liver Mitochondria and Preparation Of Matrix Prmentioning

confidence: 99%

“…For column centrifugation [8,17], a column (5 ml syringe) filled with Sephadex G25 Superfine was equilibrated with 4i2 ml of 20 mM NH % HCO $ buffer (pH 8.1) by centrifugation at 450 g for 3i5 min and then for 10 min. The assay sample (500 µl) was applied to the column by centrifugation at 450 g for 10 min.…”

Section: Assay Of Coa Modification Of Proteinsmentioning

confidence: 99%

“…The existence of multiple forms has been demonstrated, for example, for 3-oxoacyl-CoA thiolases (EC 2.3.1.16) and for acetyl-CoA acetyltransferase (acetoacetyl-CoA thiolase ; EC 2.3.1.9) in mammalian mitochondria [2][3][4]. The different forms of acetyl-CoA acetyltransferase revealed a charge heterogeneity in i o [5] that could not be traced to different cDNAs [6], but resulted from a CoA modification [7,8]. Thus the fully active unmodified enzyme [9] is sequentially transformed into partially active CoA-modified forms.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Immunochemical detection of CoA-modified mitochondrial matrix proteins

Huth

Pauli

Möller

1996

Biochemical Journal

Self Cite

View full text Add to dashboard Cite

An in vitro assay mixture consisting of mitochondrial matrix proteins from rat liver and CoA resulted in the formation of CoA-modified proteins. CoA-modified proteins were demonstrated by detection of CoA. CoA was released from the proteins by dithioerythritol treatment under denaturing conditions and was identified by (a) its retention time on HPLC, (b) its absorption spectrum and (c) its activity in a CoA-specific assay. This CoA represents protein-bound CoA and, in addition, protein-bound palmitoyl-CoA when MgATP was also present in the in vitro assay. The detection of immunoreactive proteins using monospecific anti-CoA antibodies exclusively identifies CoA-modified proteins. The specificity of these antibodies can be used to identify both endogenously occurring CoA-modified proteins and proteins that have been modified in the in vitro assay. An intact thiol group of CoA is an essential precondition for the modification to occur.

show abstract