Enzyme - Glucose-6-phosphate dehydrogenase (NADP(+))

Alternative Name(s)
  • Glucose-6-phosphate dehydrogenase.
  • Glucose-6-phosphate 1-dehydrogenase.
  • GPD.
  • G6PD.
  • G6PDH.

Catalytic Activity

D-glucose 6-phosphate + NADP(+) = 6-phospho-D-glucono-1,5-lactone + H(+) + NADPH


There are no Cofactors for this Enzyme

Reaction Mechanism

    Glucose-6-phosphate dehydrogenase (G6PDH) is a ubiquitous protein, present in bacteria and all eukaryotic cell types. The enzyme catalyses the the first step in the pentose pathway: the conversion of glucose-6-phosphate to gluconolactone 6-phosphate in the presence of NADP, producing NADPH. The ubiquitous expression of the enzyme gives it a major role in the production of NADPH for the many NADPH-mediated reductive processes in all cells. Deficiency of G6PDH is a common genetic abnormality affecting millions of people worldwide. Many sequence variants, most caused by single point mutations, are known, exhibiting a wide variety of phenotypes.

    The oxidation of glucose 6-phosphate by G6PD involves general base (His240) abstraction of a proton from the C1−OH, thereby allowing transfer of the hydride from C1 to the C4 position of the nicotinamide ring of the coenzyme.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    His P11411 179 1dpg 178
    Asp P11411 178 1dpg 177
    His P11411 241 1dpg 240
    Step Components

    overall product formed, proton transfer, overall reactant used, native state of enzyme regenerated, inferred reaction step, hydride transfer

    Step 1.

    His240 abstracts a proton from the substrate, eliminating a hydride that is added to NAD(P).

    Step 2.

    Inferred return step to deprotonate His240, ready for another reaction cycle.


    The products of the reaction.

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
Glucose-6-phosphate 1-dehydrogenase Human
Probable glucose-6-phosphate 1-dehydrogenase C7.13c Fission yeast
Glucose-6-phosphate 1-dehydrogenase 1, chloroplastic Mouse-ear cress
Glucose-6-phosphate 1-dehydrogenase, cytoplasmic isoform Potato
Glucose-6-phosphate 1-dehydrogenase X Mouse