2h42
From Proteopedia
Crystal structure of PDE5 in complex with sildenafil
Structural highlights
FunctionPDE5A_HUMAN Plays a role in signal transduction by regulating the intracellular concentration of cyclic nucleotides. This phosphodiesterase catalyzes the specific hydrolysis of cGMP to 5'-GMP. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPhosphodiesterase-5 (PDE5) is the target for sildenafil, vardenafil, and tadalafil, which are drugs for treatment of erectile dysfunction and pulmonary hypertension. We report here the crystal structures of a fully active catalytic domain of unliganded PDE5A1 and its complexes with sildenafil or icarisid II. These structures together with the PDE5A1-isobutyl-1-methylxanthine complex show that the H-loop (residues 660-683) at the active site of PDE5A1 has four different conformations and migrates 7-35A upon inhibitor binding. In addition, the conformation of sildenafil reported herein differs significantly from those in the previous structures of chimerically hybridized or almost inactive PDE5. Mutagenesis and kinetic analyses confirm that the H-loop is particularly important for substrate recognition and that invariant Gly(659), which immediately precedes the H-loop, is critical for optimal substrate affinity and catalytic activity. Multiple conformations of phosphodiesterase-5: implications for enzyme function and drug development.,Wang H, Liu Y, Huai Q, Cai J, Zoraghi R, Francis SH, Corbin JD, Robinson H, Xin Z, Lin G, Ke H J Biol Chem. 2006 Jul 28;281(30):21469-79. Epub 2006 May 30. PMID:16735511[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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