Beta-oxidation enzymes in normal human muscle and in muscle from a patient with an unusual form of myopathic carnitine deficiency.
In a reported patient with myopathic carnitine deficiency, addition of exogenous carnitine to muscle homogenates failed to correct palmitate oxidation, and oral carnitine was of no clinical benefit. In a muscle biopsy from this patient, we found that, in contrast to the marked deficiency of free carnitine (3% of normal) short- and medium-chain acylcarnitines were in the normal range and long-chain acylcarnitine was increased almost four times. As this result confirmed the hypothesis of a muscle defect of mitochondrial oxidation of palmitate, all eight enzymes of beta-oxidation were measured spectrophotometrically in the muscle extract. None of them was found to be defective. These data suggest that the underlying biochemical abnormality in this patient may be a deficiency of the carnitine-acylcarnitine translocase system or a defective interaction between acyl-CoA dehydrogenase and its flavoprotein coenzyme.
Trevisan
C P
CP
Reichmann
H
H
DeVivo
D C
DC
DiMauro
S
S
D000217:Acyltransferases / Q000378:metabolism*; D000328:Adult; D002331:Carnitine / Q000172:deficiency* / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D002675:Child, Preschool; D003066:Coenzyme A Ligases / Q000378:metabolism*; D005260:Female; D006801:Humans; D009132:Muscles / Q000201:enzymology* / Q000473:pathology; D009135:Muscular Diseases / Q000201:enzymology*; D009468:Neuromuscular Diseases / Q000201:enzymology; D012016:Reference Values; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000217:Acyltransferases; D002334:Carnitine O-Palmitoyltransferase; D003066:Coenzyme A Ligases; C090799:FAA2 protein, S cerevisiae; D000098859:Long-Chain-Fatty-Acid-CoA Ligase; D002331:Carnitine