Acyl-CoA dehydrogenase only active with R- and S-2-methyl-C15-CoA. A + a 2,3-saturated acyl-CoA = a 2,3-dehydroacyl-CoA + AH2 Widely expressed with highest expression in fetal brain, followed by heart, muscle, kidney and adult brain. Expression levels varying from isoform to isoform. Belongs to the acyl-CoA dehydrogenase family. Truncated N-terminus.