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A purified bovine lung cGMP-binding cGMP-specific phosphodiesterase (cG-BPDE) was rapidly phosphorylated by purified bovine lung cGMP-dependent protein kinase (cGK). Within a physiological concentration range, cGK catalyzed phosphorylation of cG-BPDE at a rate approximately 10 times greater than did equimolar concentrations of purified catalytic subunit of(More)
Intracellular cAMP and cGMP levels are increased in response to a variety of hormonal and chemical stimuli; these nucleotides play key roles as second messenger signals in modulating myriad physiological processes. The cAMP-dependent protein kinase and cGMP-dependent protein kinase are major intracellular receptors for these nucleotides, and the actions of(More)
A bovine lung cGMP-binding phosphodiesterase (cG-BPDE) was purified to homogeneity and exhibited specific cGMP hydrolytic (Km = 5.6 microM) and cGMP binding (half-maximum approximately 0.2 microM) activities which comigrated throughout the purification. A chimeric structure was suggested for cG-BPDE since DEAE chromatography of a partial alpha-chymotryptic(More)
In addition to its cGMP-selective catalytic site, cGMP-binding cGMP-specific phosphodiesterase (PDE5) contains two allosteric cGMP-binding sites and at least one phosphorylation site (Ser92) on each subunit [Thomas, M.K., Francis, S.H. & Corbin, J.D. (1990) J. Biol. Chem. 265, 14971-14978]. In the present study, prior incubation of recombinant bovine PDE5(More)
To date, studies suggest that biological signaling by nitric oxide (NO) is primarily mediated by cGMP, which is synthesized by NO-activated guanylyl cyclases and broken down by cyclic nucleotide phosphodiesterases (PDEs). Effects of cGMP occur through three main groups of cellular targets: cGMP-dependent protein kinases (PKGs), cGMP-gated cation channels,(More)
[3H]Vardenafil (Levitra) or [3H]tadalafil (Cialis) binding was used to quantify PDE5 in rat lung and heart tissue. Each radioligand bound to purified recombinant phosphodiesterase-5 (PDE5) or to PDE5 in crude extracts with strong affinity, high specificity, slow dissociation, and good stoichiometry. PDE5, the only 3H inhibitor-binding protein detected in(More)
The cGMP-binding cGMP-specific phosphodiesterase (PDE5) degrades cGMP and regulates the intracellular level of cGMP in many tissues, including the smooth muscle of the corpus cavernosum of the penis. Sildenafil (Viagra), a specific PDE5 inhibitor, promotes penile erection by blocking the activity of PDE5, which causes cGMP to accumulate in the corpus(More)