Direct demonstration that the deficient oxidation of very long chain fatty acids in X-linked adrenoleukodystrophy is due to an impaired ability of peroxisomes to activate very long chain fatty acids.
A method was developed to prepare peroxisome-enriched fractions depleted of microsomes and mitochondria from cultured skin fibroblasts. The method consists of differential centrifugation of a postnuclear supernatant followed by density gradient centrifugation on a discontinuous Metrizamide gradient. The activity of hexacosanoyl-CoA synthetase was subsequently measured in postnuclear supernatants and peroxisome-enriched fractions prepared from cultured skin fibroblasts from control subjects and patients with X-linked adrenoleukodystrophy. Whereas the hexacosanoyl-CoA synthetase activity in postnuclear supernatants of X-linked adrenoleukodystrophy fibroblasts was only slightly decreased (77.8 +/- 4.4% of control (n = 15], enzyme activity was found to be much more markedly reduced in peroxisomal fractions isolated from the mutant fibroblasts (19.6 +/- 6.7% of control (n = 5]. This is a direct demonstration that the defect in X-linked adrenoleukodystrophy is at the level of a deficient ability of peroxisomes to activate very long chain fatty acids, as first suggested by Hashmi et al. [Hashmi, M., Stanley, W. and Singh, I. (1986) FEBS Lett. 86, 247-250].
Wanders
R J
RJ
Department of Pediatrics, University Hospital Amsterdam, The Netherlands.
van Roermund
C W
CW
van Wijland
M J
MJ
Schutgens
R B
RB
van den Bosch
H
H
Schram
A W
AW
Tager
J M
JM
D000326:Adrenoleukodystrophy / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002458:Cell Fractionation; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002549:Diffuse Cerebral Sclerosis of Schilder / Q000378:metabolism*; D064429:Fatty Acid Synthases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D006801:Humans; D008830:Microbodies / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D012867:Skin / Q000201:enzymology
D005227:Fatty Acids; C017364:hexacosanoic acid; D002374:Catalase; D064429:Fatty Acid Synthases