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)

As revealed by spectrophotometry, native but not heat-inactivated influenza virus in the presence of ATP reduced the activity of calcium-dependent regulator protein-stimulated 3',5'-c AMP-phosphodiesterase (CDR-PDE). ATP could be partially replaced by ADP but not by AMP. The degree of CDR-PDE inhibition increased with increasing virus concentration. But at very high virus concentrations the rate of 3',5'-c AMP hydrolysis by CDR-PDE was not linearly dependent on time. At appropriate virus concentrations the degree of inhibition of CDR-PDE activity remained unchanged for the whole reaction time.
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PMID:Role of calcium-dependent regulator protein (CDR) in inhibition of 3',5'-c AMP-phosphodiesterase by influenza virus. II. Kinetic studies on inhibition of CDR-dependent phosphodiesterase by influenza virus. 4 Apr 17

The calcium-sensitive phosphodiesterase-stimulating activity sometimes associated with parvalbumin preparations is due to contaminating (less than 0.1%) amounts of carp muscle CDR (calcium-dependent regulator)-like protein. This protein can be resolved from parvalbumins by Sephadex G-75 chromatography and has many characteristics of the CDR. Parvalbumin itself causes a nonspecific stimulation of phosphodiesterase at all calcium concentrations which, in the presence of CDR, can cause an apparent shift to a lower concentration of the calcium level required for half-maximal stimulation.
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PMID:Inability of parvalbumin to function as a calcium-dependent activator of cyclic nucleotide phosphodiesterase activity. 22 Feb 39

Cyclic nucleotide phosphodiesterase activity (3':5'-cyclic-AMP 5'-nucleotidohydrolase, EC 3.1.4.17), which is activatable by Ca(2+)-dependent regulator protein (CDR), has been identified in cycled microtubule preparations from bovine brain. By using various methods to fractionate the microtubule preparation into subfractions (e.g., phosphocellulose chromatography to obtain purified 6S tubulin and soluble microtubule-associated proteins, and gel exclusion chromatography on Bio-Gel A-150m to obtain 10-nm filaments), we found that all the fractions exhibited some enzymic activity, but that most of the phosphodiesterase activity was localized in the 10-nm filament fraction. By using cyclic GMP as substrate, a specific activity of 921 +/- 168 pmol/mg of filament protein.min was determined. Also, 10-nm filaments were prepared directly from brain homogenates by differential centrifugation and gel exclusion chromatography. This fraction also contained phosphodiesterase activity but of slightly lower specific activity (752 +/- 9 pmol/mg of protein.min). The filament-associated enzymic activity was stable during storage (-70 degrees C) and to several salt extractions at moderate ionic strength (0.5 M); the latter finding indicates that the phosphodiesterase is not adsorbed to the filaments via nonspecific electrostatic interactions. Although a chelating agent was present in the initial homogenization buffer and generally in all buffers used in preparing fractions, an activator of a smooth muscle phosphodiesterase was released upon boiling the 10-nm filaments. This activator obtained in the boiled supernatant was Ca(2+)-sensitive, trifluoperazine-sensitive, and stimulated smooth muscle phosphodiesterase to nearly the same extent as purified (exogenous) CDR; thus, it probably represents filament-associated CDR.
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PMID:Cyclic nucleotide phosphodiesterase activity in 10-nm filaments and microtubule preparations from bovine brain. 22 49

AFTER exposure to secretagogues the small intestine changes from a tissue that absorbs fluid and electrolyte from lumen to blood into a tissue that secretes electrolyte and fluid into the lumen(1-4). It has been shown that this secretion results from an increase in the passive Cl(-) permeability of the mucosal border, which permits Nad to leak passively from the lateral intercellular spaces, where it is present at hypertonic concentrations(5), into the mucosal bathing solution. Na(+) and water, electroosmotically coupled to Na(+) movement, leak through the tight junctions(1,2), and Cl(-) leaks through relatively anhydrous anion-selective channels, induced withira the mucosal border by secretagogues. The increased reflux of NaCl from the lateral intercellular space accounts for both the apparent decrease in electroneutral NaCl uptake across the mucosal border induced by secretagogues and the apparent increase in active CP secretion and short-circuit current(3,6,7). We have investigated the mechanism by which intestinal secretagogues increase passive Cl(-) permeability and thereby cause secretion. Cl(-) permeability is increased by several secretagogues, some of which, such as theophylline and choleragen, increase intracellular cyclic AMP concentration, and others, such as A23187, the Ca(2+) ionophore, or carbachol, do not(8). Thus there has been no known common mode of secretory induction. To investigate this problem we used two drugs that prevent intestinal secretion in vitro, RMI 12330A (Richardson Merrell), and the antipsychotic pheno-thiazine trifluoperazine (Stelazine, Smith, Kline and French). RMI 12330A prevents secretion by inhibiting choleragen-induced adenylyl cyclase activity(9). Stelazine inhibits phosphodiesterase in tissues(11,12) by preventing the activation of the enzyme by Ca(2+)-dependent regulator protein, CDR. We report here that it also inhibits Cl(-) secretion and binds to CDR.
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PMID:Role of Ca(2+)-dependent regulator protein in intestinal secretion. 1606 90