The mammalian X-linked housekeeping NADP+-dependent enzyme glucose-6-phosphate dehydrogenase (G6PD) catalyzes the first and rate-limiting of the pentose phosphate shunt where glucose-6-phosphate (G6P) is converted to 6-phosphoglucono-delta-lactone with the concomitant reduction of one NADP+ to NADPH. This pentose phosphate pathway (PPP) is primarily important due to its production of NADPH and pentose sugars which provide the cell with building blocks for nucleic acid biosynthesis. The NADPH generated in this first rate-limiting reaction is essential for protection of cells against oxidative damage as NADPH acts as the principal modulator of intracellular redox homeostasis within a cell1,2. NADPH is involved in a multitude of pathways that include roles as: the chief reducing equivalent in redox reactions that take place within erythrocytes involving glutathione reduction, an important regulator involved in the maintenance of optimum pH required for the stimulation of cell growth and proliferation by epidermal growth factor, and the sole source of NADPH production in some cell types such as erythrocytes.3,4,5,6
| Tetramer vs. Dimer | Page 1 |
| hsG6PD with NADP+ and G6P bound | Page 2 |
| 35% sequence identity reveals key residues | Page 3 |
| Coordinating residues of coenzyme binding site | Page 4 |
| The Catalytic Dyad | Page 5 |
| Rare dual-specificity of lmG6PD | Page 6 |