Publications

• Expression and characterization of mutations in human very long-chain acyl-CoA dehydrogenase using a prokaryotic system.

  Goetzman E.S., Wang Y., He M., Mohsen A.W., Ninness B.K., Vockley J.

  Very long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the first enzymatic step in the mitochondrial beta-oxidation of fatty acids 14-20 carbons in length. More than 100 cases of VLCAD deficiency have been reported with the disease varying from a severe, often fatal neonatal form to a mild adult ... >> More

  Very long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the first enzymatic step in the mitochondrial beta-oxidation of fatty acids 14-20 carbons in length. More than 100 cases of VLCAD deficiency have been reported with the disease varying from a severe, often fatal neonatal form to a mild adult-onset form. VLCAD is distinguished from matrix-soluble acyl-CoA dehydrogenases by its unique C-terminal domain, homodimeric structure, and localization to the inner mitochondrial membrane. We have for the first time expressed and purified VLCAD using a bacterial system. Recombinant VLCAD had similar biochemical properties to those reported for native VLCAD and the bacterial system was used to study six previously described disease-causing missense mutations including the two most common mild mutations (T220M, V243A), a mutation leading to the severe disease phenotype (R429W), and three mutations in the C-terminal domain (A450P, L462P, and R573W). Of particular interest was the finding that the A450P and L462P bacterial extracts had normal or increased amounts of VLCAD antigen and activity. In the pure form L462P had roughly 30% of wild-type activity while A450P was normal. Using computer modeling both mutations were mapped to a predicted charged surface of VLCAD that we postulate interacts with the mitochondrial membrane. In a membrane pull down assay both mutants showed greatly reduced mitochondrial membrane association, suggesting a mechanism for the disease in these patients. In summary, the bacterial expression system developed here will significantly advance our understanding of both the clinical aspects of VLCAD deficiency and the basic biochemistry of the enzyme. << Less

  Mol. Genet. Metab. 91:138-147(2007) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.

• Identification and characterization of new long chain acyl-CoA dehydrogenases.

  He M., Pei Z., Mohsen A.W., Watkins P., Murdoch G., Van Veldhoven P.P., Ensenauer R., Vockley J.

  Long-chain fatty acids are an important source of energy in muscle and heart where the acyl-CoA dehydrogenases (ACADs) participate in consecutive cycles of β-oxidation to generate acetyl-CoA and reducing equivalents for generating energy. However, the role of long-chain fatty acid oxidation in the ... >> More

  Long-chain fatty acids are an important source of energy in muscle and heart where the acyl-CoA dehydrogenases (ACADs) participate in consecutive cycles of β-oxidation to generate acetyl-CoA and reducing equivalents for generating energy. However, the role of long-chain fatty acid oxidation in the brain and other tissues that do not rely on fat for energy is poorly understood. Here we characterize two new ACADs, ACAD10 and ACAD11, both with significant expression in human brain. ACAD11 utilizes substrates with primary carbon chain lengths between 20 and 26, with optimal activity towards C22CoA. The combination of ACAD11 with the newly characterized ACAD9 accommodates the full spectrum of long chain fatty acid substrates presented to mitochondrial β-oxidation in human cerebellum. ACAD10 has significant activity towards the branched-chain substrates R and S, 2 methyl-C15-CoA and is highly expressed in fetal but not adult brain. This pattern of expression is similar to that of LCAD, another ACAD previously shown to be involved in long branched chain fatty acid metabolism. Interestingly, the ACADs in human cerebellum were found to have restricted cellular distribution. ACAD9 was most highly expressed in the granular layer, ACAD11 in the white matter, and MCAD in the molecular layer and axons of specific neurons. This compartmentalization of ACADs in the human central nerve system suggests that β-oxidation in cerebellum participates in different functions other than generating energy, for example, the synthesis and/or degradation of unique cellular lipids and catabolism of aromatic amino acids, compounds that are vital to neuronal function. << Less

  Mol. Genet. Metab. 102:418-429(2011) [PubMed] [EuropePMC]

  This publication is cited by 13 other entries.