Lazo O, Contreras M, Bhushan A, Stanley W, Singh I
Department of Pediatrics, Medical University of South Carolina, Charleston 29425.
Arch Biochem Biophys. 1989 May 1;270(2):722-8. doi: 10.1016/0003-9861(89)90555-9.
Very long chain fatty acids (lignoceric acid) are oxidized in peroxisomes and pathognomonic amounts of these fatty acids accumulate in X-adrenoleukodystrophy (X-ALD) due to a defect in their oxidation. However, in cellular homogenates from X-ALD cells, lignoceric acid is oxidized at a rate of 38% of control cells. Therefore, to identify the source of this residual activity we raised antibody to palmitoyl-CoA ligase and examined its effect on the activation and oxidation of palmitic and lignoceric acids in isolated peroxisomes from control and X-ALD fibroblasts. The normalization of peroxisomal lignoceric acid oxidation in the presence of exogenously added acyl-CoA ligases and along with the complete inhibition of activation and oxidation of palmitic and lignoceric acids in peroxisomes from X-ALD by antibody to palmitoyl-CoA ligase provides direct evidence that lignoceroyl-CoA ligase is deficient in X-ALD and demonstrates that the residual activity for the oxidation of lignoceric acid was derived from the activation of lignoceric acid by peroxisomal palmitoyl-CoA ligase. This antibody inhibited the activation and oxidation of palmitic acid but had little effect on these activities for lignoceric acid in peroxisomes from control cells. Furthermore, these data provide evidence that peroxisomal palmitoyl-CoA and lignoceroyl-CoA ligases are two different enzymes.
极长链脂肪酸（二十四烷酸）在过氧化物酶体中被氧化，由于其氧化缺陷，这些脂肪酸的特征性量在X-肾上腺脑白质营养不良（X-ALD）中积累。然而，在来自X-ALD细胞的细胞匀浆中，二十四烷酸的氧化速率为对照细胞的38%。因此，为了确定这种残余活性的来源，我们制备了针对棕榈酰辅酶A连接酶的抗体，并研究了其对来自对照和X-ALD成纤维细胞的分离过氧化物酶体中棕榈酸和二十四烷酸的活化和氧化的影响。在外源添加酰基辅酶A连接酶的情况下，过氧化物酶体中二十四烷酸氧化的正常化，以及棕榈酰辅酶A连接酶抗体对X-ALD过氧化物酶体中棕榈酸和二十四烷酸的活化和氧化的完全抑制，提供了直接证据，表明二十四烷酰辅酶A连接酶在X-ALD中缺乏，并证明二十四烷酸氧化的残余活性源自过氧化物酶体棕榈酰辅酶A连接酶对二十四烷酸的活化。这种抗体抑制了棕榈酸的活化和氧化，但对对照细胞过氧化物酶体中二十四烷酸的这些活性影响很小。此外，这些数据提供了证据，表明过氧化物酶体棕榈酰辅酶A和二十四烷酰辅酶A连接酶是两种不同的酶。
