In enzymology, a 2-methylacyl-CoA dehydrogenase is an enzyme that catalyzes the chemical reaction 2-methylbutanoyl-CoA + acceptor ⇌ {\displaystyle \rightleftharpoons } 2-methylbut-2-enoyl-CoA + reduced acceptorThus, the two substrates of this enzyme are 2-methylbutanoyl-CoA and acceptor, whereas its two products are 2-methylbut-2-enoyl-CoA and reduced acceptor. Wikipedia