Disease relevance of Acads

• Glu368, the hypothetical active site catalytic residue of rat SCAD, was replaced with Asp, Gly, Gln, Arg, and Lys and the wild type and mutant SCADs were produced in Escherichia coli and purified [1].
• Three-dimensional structure of butyryl-CoA dehydrogenase from Megasphaera elsdenii [2].

High impact information on Acads

• In one cell line (YH2065) no SCAD protein was detectable [3].
• Using a [35S]methionine labeling/immunoprecipitation technique, we have previously shown that cultured skin fibroblast from three patients with short chain acyl-CoA dehydrogenase (SCAD) deficiency each synthesize a normal-sized (41 kD) variant SCAD in an amount comparable to that of normal cells [3].
• [35S]Methionine-labeling in the presence of rhodamine 6G demonstrated that SCAD-YH2065 was synthesized as a 44-kD precursor and imported normally into mitochondria, as were the normal SCAD and two other variant SCADs, excluding the possibility that SCAD-YH2065 is a truncated precursor that cannot be imported into mitochondria [3].
• A single 1773 base pair cDNA for rat SCAD covers the entire coding region (414 amino acids), including the 26-amino acid leader peptide and the 388-amino acid mature peptide [4].
• In this study, in vitro site-directed mutagenesis was used to investigate the effect of changing the position of the catalytic carboxylate on substrate specificity in short chain acyl-CoA dehydrogenase (SCAD) [1].

Chemical compound and disease context of Acads

• The crystal structure of butyryl-CoA dehydrogenase (BCAD) from Megasphaera elsdenii complexed with acetoacetyl-CoA has been solved at 2.5 A resolution [2].

Biological context of Acads

• These results confirm the identity of Glu368 as the catalytic residue of rat SCAD and suggest that alteration of the position of the catalytic carboxylate can modify substrate specificity [1].
• To clone the gene, the amino acid sequence of the 50 N-terminal residues of SCAD from M. elsdenii was determined [5].
• 5. Many of the effects of methylenecyclopropylpyruvate observed are consistent with inhibition of butyryl-CoA dehydrogenase and of specific CoA-dependent enzymes involved in gluconeogenesis [6].
• The cloned SCAD gene contained an open reading frame which revealed a high degree of sequence identity with an open reading frame protein sequence of the human SCAD and the rat medium-chain acyl-CoA dehydrogenase (MCAD) (44% and 36% identical residues in paired comparisons for human SCAD and rat MCAD, respectively) [5].
• Considering the importance of CK for brain energy homeostasis, it is proposed that the inhibition of Mi-CK activity may be associated to the neurological symptoms characteristic of SCAD deficiency [7].

Associations of Acads with chemical compounds

• The recombinant wild type SCAD kcat/K(m) values for butyryl-hexanoyl-, and octanoyl-CoA were 220, 22, and 3.2 microM-1 min-1, respectively, while the Glu368Asp mutant gave kcat/K(m) of 81, 12, and 1.4 microM-1 min-1, respectively, for the same substrates [1].
• After hypoglycin administration, hepatic mitochondrial butyryl-CoA dehydrogenase activity was inhibited by more than 90% and, surprisingly, the activity of the peroxisomal enzymes studied was largely preserved [8].
• In addition, a site-directed Glu367 Gln mutant of SCAD expressed from a pUC119 vector was shown to have minimal reductive and oxidative pathway activity with butyryl-CoA and crotonyl-CoA, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)[5]
• Modifications by penicillamine hydantoin of various subcellular markers enzymes (lactate dehydrogenase, N-acetyl beta-glucosaminidase, arylsulfatase C, butyryl-CoA dehydrogenase, lauryl-CoA and glycolate oxidases) were of weak amplitude consisting of either inhibition, inactivation or stimulation [9].
• Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is an inherited metabolic disorder biochemically characterized by tissue accumulation of predominantly ethylmalonic acid (EMA) and clinically by neurological dysfunction [7].

Analytical, diagnostic and therapeutic context of Acads

• These results indicate that the mutations responsible for SCAD deficiency are heterogeneous, and emphasize the importance of using both radiolabeling and immunoblotting when evaluating such genetic defects at the protein level [3].

References