Short/branched chain specific acyl-CoA dehydrogenase（ACADSB) belongs to the acyl-CoA dehydrogenase family of enzymes which catalyze the dehydrogenation of acyl-CoA derivatives in the metabolism of fatty acids or branch chained amino acids. ACADSB catalyzes the degradation of L-isoleucine while having the highest affinity for（s)-2-methylbutyryl-CoA， isobutyryl-CoA and 2-methylhexanoyl-CoA as substrates. ACADSB may use valproyl-CoA as substrate and have a role in regulating the metabolic flux of valproic acid in the development of toxicity of this agent. ACADSB gene defects cause the short/branched-chain acyl-CoA dehydrogenase deficiency（SBCADD)， which is an autosomal recessive disorder characterized by an increase of 2-methylbutyrylglycine and 2-methylbutyrylcarnitine in blood and urine.
