Inhibition of pigeon breast muscle α-ketoglutarate dehydrogenase by phosphonate analogues of α-ketoglutarate

Succinylphosphonate (SP) is a powerful inhibitor or α-ketoglutarate dehydrogenase (KGD). Methylation of the phosphonate reduces its inhibitory effect. The complex of KGD with SP undergoes a kinetically slow transition similar to the process observed during catalysis. α-Ketoglutarate binds to the enzyme—inhibitor complex, preventing its isomerisation.