Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Resonance energy transfer was used to monitor the interactions of the gamma subunit of the cyclic GMP phosphodiesterase (gamma PDE) with the alpha and beta subunits, which together comprise the catalytic core of the enzyme (alpha beta PDE). An iodoacetamidofluorescein (IAF)-labeled alpha beta PDE (IAF-PDEt) served as the acceptor species in these experiments while a coumarin maleimide-modified gamma PDE (CPM-gamma PDE) served as the fluorescent donor. Trypsin treatment of an IAF-labeled, intact phosphodiesterase (PDE) complex resulted in the selective proteolysis of the gamma PDE and full activation of enzyme activity. The binding of IAF-PDEt to the CPM-gamma PDE was monitored directly by measuring the quenching (25-35%) of the CPM fluorescence emission or by measuring the changes in the rate cGMP hydrolysis by IAF-PDEt using the pH electrode method. Both methods yielded titration curves which were well fitted using a single affinity constant (Kd approximately 1-2 nM). Under conditions where added CPM-gamma PDE resulted in complete inhibition of the IAF-PDEt activity and, conversely, a maximal quenching of the CPM-gamma PDE fluorescence by added IAF-PDEt, the subsequent addition of guanosine 5'-O-(thiotriphosphate) bound form of the alpha subunit of transducin (alpha TGTP gamma S) restored approximately 50% of the enzyme activity while restoring < 30% of the CPM-gamma PDE fluorescence emission. Based on these results, we suggest that a portion of the observed PDE activation by alpha TGTP gamma S occurs via an associated complex of alpha TGTP gamma S and the enzyme.
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PMID:Regulation of the cGMP phosphodiesterase in bovine rod outer segments. Use of resonance energy transfer to distinguish between associative and dissociative activation mechanisms. 838 26

Despite its importance in reproductive biology and women's health, a detailed molecular-level understanding of the human endometrium is lacking. Indeed, no comprehensive studies have been undertaken to elucidate the important protein expression differences between the endometrial glandular epithelium and surrounding stroma during the proliferative and midsecretory phases of the menstrual cycle. We utilized laser microdissection to harvest epithelial cells and stromal compartments from proliferative and secretory premenopausal endometrial tissue and performed a global, quantitative mass spectrometry-based proteomics analysis. This analysis identified 1224 total proteins from epithelial cells, among which 318 were differentially abundant between the proliferative and secretory phases (q < 0.05), and 1005 proteins from the stromal compartments, 19 of which were differentially abundant between the phases (q < 0.05). Several proteins were chosen for validation by immunohistochemistry in an independent set of uterine tissues, including carboxypeptidase M, tenascin C, neprilysin, and ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3). ENPP3, which was elevated in epithelial glandular cells in the secretory phase, was confirmed to be elevated in midsecretory-phase baboon uterine lavage samples and also observed to have an N-linked glycosylated form that was not observed in the proliferative phase. This study provides a detailed view into the global proteomic alterations of the epithelial cells and stromal compartments of the cycling premenopausal endometrium. These proteomic alterations during endometrial remodeling provide a basis for numerous follow-up investigations on the function of these differentially regulated proteins and their role in reproductive biology and endometrial pathologies.
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PMID:Proteomics of the human endometrial glandular epithelium and stroma from the proliferative and secretory phases of the menstrual cycle. 2569 23