Phosphodiesterase-5
| Phosphodiesterase-5 | ||
|---|---|---|
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| according to PDB 3bjc ; Magnesium ion (green), zinc ion (blue), inhibitor "component 12" (red) | ||
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Existing structural data : 1rkp , 1t9r , 1tbf , 1udt , 1xoz , 2chm , 2h40 , 3b2r |
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| Properties of human protein | ||
| Mass / length primary structure | 875 amino acids | |
| Cofactor | 2A 2+ with A = Zn, Mn, Mg, Co | |
| Isoforms | PDE5A1, PDE5A2 | |
| Identifier | ||
| Gene name | PDE5 | |
| External IDs |
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| Enzyme classification | ||
| EC, category | 3.1.4.35 , phosphatase | |
| Response type | hydrolysis | |
| Substrate | 3 ', 5'-cGMP | |
| Products | Guanosine 5'-phosphate | |
| Occurrence | ||
| Homology family | cGMP-cleaving PDE | |
| Parent taxon | Euteleostomi | |
Phosphodiesterase-5 (PDE5) is the name for one of the enzymes that cleave the phosphoric acid ester bond in cGMP , producing 5'- GMP . In humans, the phosphodiesterase-5 comes in the smooth muscle of the Penisschwellkörpers ( corpus cavernosum ) and the pulmonary artery before. Blocking the cGMP breakdown by inhibiting PDE5 (with, for example, sildenafil ) leads to increased signals in the relaxation signaling pathways and, in particular, to increased blood supply in the penile erectile tissue and a decrease in pressure in the blood vessels of the lungs.
In addition to PDE5, there are other phosphodiesterases that only cleave cGMP . If they are involved in the transmission of visual cues they are numbered 6, and if they have manganese as a cofactor they are numbered 9. The PDE11 cleaves both cAMP and cGMP.
Catalyzed reaction
-
+ H 2 O → 
+ 2 H +
- cGMP is degraded to 5'-GMP.
Medical importance
So-called phosphodiesterase-5 inhibitors ( PDE-5 inhibitors ), such as sildenafil ( Viagra ), tadalafil ( Cialis ) and vardenafil ( Levitra ), increase the cGMP concentration for a short time , which leads to a relaxation of the vascular muscles and thus to a widening of them, which then in turn leads to increased blood flow and an erection of the penis and a drop in blood pressure in the lungs. They are used to treat erectile dysfunction and pulmonary arterial hypertension .
Individual evidence
- ↑ Phosphodiesterase-5. In: Online Mendelian Inheritance in Man . (English).
