scholarly journals Acyl-CoA dehydrogenase activity in the riboflavin-deficient rat. Effects of starvation

1987 ◽  
Vol 244 (2) ◽  
pp. 387-391 ◽  
Author(s):  
N S Ross ◽  
C L Hoppel
Keyword(s):  
Fatty Acid ◽  
Dehydrogenase Activity ◽  
Fatty Acid Oxidation ◽  
Specific Activity ◽  
Short Chain ◽  
Acid Oxidation ◽  
Riboflavin Deficiency ◽  
Mitochondrial Fatty Acid ◽  
Chain Acyl ◽  
Riboflavin Deficient

Riboflavin deficiency in weanling rats causes a metabolic disorder characterized by failure to oxidize fatty acids. The disorder is similar to that seen in several human diseases, some of which are responsive to pharmacological doses of riboflavin. Previous analysis of the riboflavin-deficient rat has shown that the failure of fatty acid oxidation is due to a decrease in the activity of the acyl-CoA dehydrogenases of beta-oxidation. The activity of these flavoenzymes in liver rapidly decreases when a riboflavin-deficient diet is initiated. The objectives of these experiments were to analyse the effects of starvation on liver mitochondria isolated from the riboflavin-deficient rat. Our studies show that the decreased mitochondrial fatty acid oxidation induced by riboflavin deficiency is partially reversed by starvation. The extent of this reversal is proportional to the duration of starvation. The starvation-associated increase in fatty acid oxidation is mediated by an increase in the mitochondrial short-chain acyl-CoA dehydrogenase activity. The activity of this enzyme is increased such that the ratio of short-chain acyl-CoA dehydrogenase apoenzyme to holoenzyme does not change. We conclude that short-chain acyl-CoA dehydrogenase activity is limiting for fatty acid oxidation when its activity falls below a critical point. The increased mitochondrial specific activity of short-chain acyl-CoA dehydrogenase during starvation may result from an increased availability of flavin coenzyme or an increase in enzyme catalytic efficiency.

Medium- and Short-Chain L-3-Hydroxyl-Acetyl-Coenzyme A Deficiency: A New Identified Mutation in Four Cases

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S9-S9
Author(s):  
Sheng Feng ◽  
Deborah Cooper ◽  
Lu Tan ◽  
Gail Meyers ◽  
Michael Bennett
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Coenzyme A ◽  
Short Chain ◽  
Acid Oxidation ◽  
Sequencing Analysis ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid ◽  
Chain Acyl ◽  
Unusual Phenotype

Abstract Medium- and short-chain L-3-hydroxyacyl-coenzyme A dehydrogenase (M/SCHAD, SCHAD) deficiency is a mitochondrial fatty acid oxidation disorder (FAOD). This enzyme catalyzes the penultimate step in fatty acid oxidation, the NAD+ dependent conversion of L-3-hydroxyacyl-CoA to 3-ketoacyl-CoA for medium- and short-chain acyl-CoA intermediates (C4-C12). The clinical presentations of most patients are recurrent hypoglycemia associated with hyperinsulinism. We presented four infants with C4 acyl-carnitine elevation identified by newborn screening that also showed an unusual phenotype of congenital hypotonia and gross developmental delay. Enzymatic studies confirmed the disease. Sequencing analysis of all the HADH coding exons on the four patients revealed a homozygous variant of a novel change (c.908G>T, p.Gly303Val). Western blot analysis subsequently confirmed the lack of the SCHAD protein. In addition, there is another previously reported benign variant (c.257T>C) identified in three infants. Therefore, we postulate that the HADH variant (c.908G>T) is indeed pathogenic and associated with a severe phenotype as evidenced by the cases described herein. Population screening for the c.908G>T mutation suggests this mutation to be common among Puerto Ricans. We recommend that SCHAD deficiency is included as part of the differential diagnosis of all infants with congenital hypotonia.

scholarly journals 2-Mercaptoacetate administration depresses the β-oxidation pathway through an inhibition of long-chain acyl-CoA dehydrogenase activity

1981 ◽  
Vol 196 (3) ◽  
pp. 803-809 ◽  
Author(s):  
F Bauché ◽  
D Sabourault ◽  
Y Giudicelli ◽  
J Nordmann ◽  
R Nordmann
Keyword(s):  
Fatty Acid ◽  
Dehydrogenase Activity ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Beta Oxidation ◽  
Oxidation Pathway ◽  
Respiration Rates ◽  
Chain Acyl ◽  
The One ◽  
Mitochondrial Defect

To elucidate the mechanisms through which 2-mercaptoacetate administration inhibits fatty acid oxidation in the liver, the respiration rates induced by different substrates were studied polarographically in rat hepatic mitochondria isolated 3 h after 2-mercaptoacetate administration. Palmitoyl-L-carnitine oxidation was almost completely inhibited in either the absence or presence of malonate. Octanoate oxidation was also inhibited, and the intramitochondrial acyl-CoA content was markedly increased. The oxidation rate of pyruvate and 2-oxoglutarate on the one hand and of 3-hydroxybutyrate, succinate and glutamate on the other was either normal or only slightly decreased. In the presence of 2,4-dinitrophenol, the extent of the inhibition of palmitoyl-L-carnitine oxidation was unchanged. All these results are consistent with the hypothesis that the 2-mercaptoacetate inhibition of fatty acid oxidation is due to an inhibition of the beta-oxidation pathway itself. Finally, the mitochondrial defect responsible for this inhibition was shown to be an inhibition of palmitoyl-CoA dehydrogenase activity (EC 1.3.99.3).

scholarly journals Liberation of I4CO2from [14C]adipic acid and [14C]octanoic acid by adult rats during riboflavin deficiency and its reversal

1990 ◽  
Vol 63 (3) ◽  
pp. 553-562 ◽  
Author(s):  
C. J. Bates
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Adipic Acid ◽  
Time Course ◽  
Octanoic Acid ◽  
Urine Analysis ◽  
Acid Oxidation ◽  
Riboflavin Deficiency ◽  
Riboflavin Deficient

The purpose of the present study was to test the hypothesis that the already well-established mitochondria1 lesion in fatty acid oxidation in riboflavin-deficient experimental animals, might be accompanied by an alteration in vivo in the kinetics of oxidation of labelled adipic acid. This dicarboxylic acid was chosen for testing as a metabolic probe because a block in its oxidation was already apparent from urine analysis of riboflavin-deficient animals, whereas the oxidation of medium- or long-chain monocarboxylic acids seemed to be little affected by deficiency in vivo. Female adult Norwegian hooded rats fed on purified diets containing either 15 mg riboflavin/kg diet (controls) or about 0.4 mg/kg (riboflavin-deficient) received an intragastric dose of either [l,6-I4C] adipic acid or [l-'4C] octanoic acid. Expired carbon dioxide was then collected in an alkaline trap over 3 h, for determination of radioactivity.This test was repeated at intervals for up to 2 weeks following riboflavin repletion of the deficient animals, and in riboflavin-dosed controls. Whereas the rate and extent of ['4C]octanoic acid oxidation was not significantly affected by the deficiency or repletion, the extent of [I4C]adipic acid oxidation was markedly and significantly increased during repletion of the deficient animals. The time-course indicated a temporary overshoot, followed by a slow return to the control values over 1–2 weeks. Adipate oxidation was also much less affected by a preceding period of overnight starvation, than was octanoate oxidation. Thus, adipic acid (or a related metabolic probe) may have appropriate properties for the design of a functional test of fatty acid oxidation efficiency, during riboflavin deficiency or allied metabolic conditions in human subjects.

Substrate specificity of the 3-methylmercaptopropionyl-CoA (DmdC1) dehydrogenase from Ruegeria pomeroyi DSS-3

2021 ◽  
Author(s):  
Tao Wang ◽  
Hao Shi ◽  
William B. Whitman
Keyword(s):  
Fatty Acid ◽  
Substrate Specificity ◽  
Fatty Acid Oxidation ◽  
Short Chain ◽  
Acid Oxidation ◽  
Kinetic Properties ◽  
High Affinity ◽  
Chain Acyl ◽  
Demethylation Pathway ◽  
Ruegeria Pomeroyi

The acyl-CoA dehydrogenase family enzyme DmdC catalyzes the third step in the dimethylsulfoniopropionate (DMSP) demethylation pathway, the oxidation of 3-methylmercaptopropionyl-CoA (MMPA-CoA) to 3-methylthioacryloyl-CoA (MTA-CoA). To study its substrate specificity, the recombinant DmdC1 from Ruegeria pomeroyi was characterized. In addition to MMPA-CoA, the enzyme was highly active with short chain acyl-CoAs, with K m values for MMPA-CoA, butyryl-CoA, valeryl-CoA, caproyl-CoA, heptanoyl-CoA, caprylyl-CoA and isobutyryl-CoA of 36, 19, 7, 11, 14, 10, and 149 μM, respectively, and k cat values of 1.48, 0.40, 0.48, 0.73, 0.46, 0.23 and 0.01 sec −1 , respectively. Among these compounds, MMPA-CoA was the best substrate. The high affinity of DmdC1 for its substrate supports the model for kinetic regulation of the demethylation pathway. In contrast to DmdB, which catalyzes the formation of MMPA-CoA from MMPA, CoA and ATP, DmdC1 was not affected by physiological concentrations of potential effectors, such as DMSP, MMPA, ATP and ADP. Thus, compared to the other enzymes of the DMSP demethylation pathway, DmdC1 has only minimal adaptations for DMSP metabolism compared to other enzymes in the same family with similar substrates, supporting the hypothesis that it evolved relatively recently from a short chain acyl-CoA dehydrogenase involved in fatty acid oxidation. Importance We report the kinetic properties of DmdC1 from the model organism R. pomeroyi and close an important gap in the literature. While the crystal structure of this enzyme was recently solved and its mechanism of action described (X. Shao, H. Y. Cao, F. Zhao, M. Peng, et al., Mol Microbiol 111:1057-1073, 2019, https://doi.org/10.1111/mmi.14211 ), its substrate specificity and sensitivity to potential effectors was never examined. We show that DmdC1 has a high affinity for other short chain acyl-CoAs in addition to MMPA-CoA, which is the natural substrate in DMSP metabolism and is not affected by the potential effectors tested. This evidence supports the hypothesis that DmdC1 possesses few adaptations to DMSP metabolism and likely evolved relatively recently from a short chain acyl-CoA dehydrogenase involved in fatty acid oxidation. This work is important because it expands our understanding about the adaptation of marine bacteria to the increased availability of DMSP about 250 million years ago.

scholarly journals Hepatic peroxisomal and mitochondrial fatty acid oxidation in the riboflavin-deficient rat

1985 ◽  
Vol 229 (3) ◽  
pp. 717-721 ◽  
Author(s):  
P S Brady ◽  
C L Hoppel
Keyword(s):  
Specific Activity ◽  
Male Rats ◽  
Acid Oxidation ◽  
Riboflavin Deficiency ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Peroxisomal Protein ◽  
Wistar Strain ◽  
Mitochondrial Fatty Acid ◽  
Ad Libitum ◽  
Riboflavin Deficient

The effects of riboflavin deficiency on hepatic peroxisomal and mitochondrial palmitoyl-CoA oxidation were examined in weanling Wistar-strain male rats. The specific activities of peroxisomal catalase and palmitoyl-CoA-dependent NAD+ reduction were not affected by up to 10 weeks of riboflavin deficiency. In contrast, the specific activity of mitochondrial carnitine-dependent palmitoyl-CoA oxidation was depressed by 75% at 10 weeks of deficiency. The amount of peroxisomal protein per g of liver was not affected by riboflavin deficiency, whereas, expressed per liver, both riboflavin-deficient and pair-fed controls showed decreased peroxisomal protein compared with controls fed ad libitum. Hepatic mitochondria, but not peroxisomes, were sensitive to riboflavin deficiency.

scholarly journals Inhibition by acetyl-CoA of hepatic carnitine acyltransferase and fatty acid oxidation

1983 ◽  
Vol 216 (2) ◽  
pp. 499-502 ◽  
Author(s):  
K McCormick ◽  
V J Notar-Francesco ◽  
K Sriwatanakul
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Acetyl Coa ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Acyltransferase Activity ◽  
Carnitine Acyltransferase ◽  
Mitochondrial Transfer ◽  
Mitochondrial Fatty Acid ◽  
Chain Acyl

At micromolar concentrations, acetyl-CoA inhibited hepatic carnitine acyltransferase activity and mitochondrial fatty acid oxidation. The inhibitory effects were not nearly as potent on a molar basis as those of malonyl-CoA; nevertheless, the cytosolic concentrations of acetyl-CoA, as yet unknown, may be sufficient (greater than 30 microM) to curtail appreciably the mitochondrial transfer of long-chain acyl-CoA units and fatty acid oxidation. Hence acetyl-CoA may also partially regulate hepatic ketogenesis.

scholarly journals Acetylation of mitochondrial proteins by GCN5L1 promotes enhanced fatty acid oxidation in the heart

2017 ◽  
Vol 313 (2) ◽  
pp. H265-H274 ◽  
Author(s):  
Dharendra Thapa ◽  
Manling Zhang ◽  
Janet R. Manning ◽  
Danielle A. Guimarães ◽  
Michael W. Stoner ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Acid Oxidation ◽  
Lysine Acetylation ◽  
High Fat ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Acetylation Status ◽  
Mitochondrial Fatty Acid ◽  
Chain Acyl

Lysine acetylation is a reversible posttranslational modification and is particularly important in the regulation of mitochondrial metabolic enzymes. Acetylation uses acetyl-CoA derived from fuel metabolism as a cofactor, thereby linking nutrition to metabolic activity. In the present study, we investigated how mitochondrial acetylation status in the heart is controlled by food intake and how these changes affect mitochondrial metabolism. We found that there was a significant increase in cardiac mitochondrial protein acetylation in mice fed a long-term high-fat diet and that this change correlated with an increase in the abundance of the mitochondrial acetyltransferase-related protein GCN5L1. We showed that the acetylation status of several mitochondrial fatty acid oxidation enzymes (long-chain acyl-CoA dehydrogenase, short-chain acyl-CoA dehydrogenase, and hydroxyacyl-CoA dehydrogenase) and a pyruvate oxidation enzyme (pyruvate dehydrogenase) was significantly upregulated in high-fat diet-fed mice and that the increase in long-chain and short-chain acyl-CoA dehydrogenase acetylation correlated with increased enzymatic activity. Finally, we demonstrated that the acetylation of mitochondrial fatty acid oxidation proteins was decreased after GCN5L1 knockdown and that the reduced acetylation led to diminished fatty acid oxidation in cultured H9C2 cells. These data indicate that lysine acetylation promotes fatty acid oxidation in the heart and that this modification is regulated in part by the activity of GCN5L1. NEW & NOTEWORTHY Recent research has shown that acetylation of mitochondrial fatty acid oxidation enzymes has greatly contrasting effects on their activity in different tissues. Here, we provide new evidence that acetylation of cardiac mitochondrial fatty acid oxidation enzymes by GCN5L1 significantly upregulates their activity in diet-induced obese mice.

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