Leloir pathway

The Leloir pathway is a metabolic pathway for the catabolism of D -galactose. It is named after Luis Federico Leloir, who first described it.

In the first step, galactose mutarotase facilitates the conversion of β- D -galactose to α- D -galactose since this is the active form in the pathway. Next, α- D -galactose is phosphorylated by galactokinase to galactose 1-phosphate. In the third step, D -galactose-1-phosphate uridylyltransferase converts galactose 1-phosphate to UDP-galactose using UDP-glucose as the uridine diphosphate source. Finally, UDP-galactose 4-epimerase recycles the UDP-galactose to UDP-glucose for the transferase reaction. Additionally, phosphoglucomutase converts the D-glucose 1-phosphate to D -glucose 6-phosphate.