Pyruvate dehydrogenase reactionsStep 4 E3 (dihydrolipoyl dehydeogenase) re-oxidizes lipoamide group of E2 Cys-Cys disulfidebond in enzymeisreduced Concomitant oxidation of lipoamideFADFADHS+SSH+HSSH
Pyruvate dehydrogenase reactions Step 4 E3 (dihydrolipoyl dehydeogenase) re-oxidizes lipoamide group of E2 Cys-Cys disulfide bond in enzyme is reduced Concomitant oxidation of lipoamide
Pyruvate dehydrogenase reactionsStep 5NAD+re-oxidizes Cys sulfhydryl groups Facilitated by FAD group - appears to initially receive electrons(FADH,) before passing them on to NAD + Usually, NADH donated electrons to FAD Association with enzyme changes its propertiesNAD+NADH+H+-FADFADSHSH
Pyruvate dehydrogenase reactions Step 5 NAD+ re-oxidizes Cys sulfhydryl groups Facilitated by FAD group – appears to initially receive electrons (FADH2) before passing them on to NAD + Usually, NADH donated electrons to FAD Association with enzyme changes its properties
Summary of the pyruvate dehydrogenase reactionsNAD+-FADSH-SHNADH+H+E3-FADOHSC-TPPCOCH3Hydroxyethyl-TPPHSLipoamideE1E2HSO0CH3CH3-CoAPyruvateAcetyl-CoAHSCoAAcetyl-dihydrolipoamide
Summary of the pyruvate dehydrogenase reactions