Very long chain fatty acid β-oxidation by subcellular fractions of normal and Zellweger syndrome skin fibroblasts
1987; Elsevier BV; Volume: 257; Issue: 2 Linguagem: Inglês
10.1016/0003-9861(87)90570-4
ISSN1096-0384
AutoresHarmeet Singh, Nicholas Derwas, A. Poulos,
Tópico(s)Metabolism and Genetic Disorders
ResumoVery long chain fatty acid (VLCFA) β-oxidation was compared in homogenates and subcellular fractions of cultured skin fibroblasts from normal individuals and from Zellweger patients who show greatly reduced numbers of peroxisomes in their tissues. β-Oxidation of lignoceric (C24:0) acid was greatly reduced compared to controls in the homogenates and the subcellular fractions of Zellweger fibroblasts. The specific activity of C24:0 acid β-oxidation was highest in the crude peroxisomal pellets of control fibroblasts. Fractionation of the crude mitochondrial and the crude peroxisomal pellets on Percoll density gradients revealed that the C24:0 acid oxidation was carried out entirely by peroxisomes, and the peroxisomal β-oxidation activity was missing in Zellweger fibroblasts. In contrast to the β-oxidation of C24:0 acid, the β-oxidation of C24:0 CoA was observed in both mitochondria and peroxisomes. We postulate that a very long chain fatty acyl CoA (VLCFA CoA) synthetase, which is different from long chain fatty acyl CoA synthetase, is required for the effective conversion of C24:0 acid to C24:0 CoA. The VLCFA CoA synthetase appears to be absent from the mitochondrial membrane but present in the peroxisomal membrane.
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