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

A comparative study on the structure of nonactivated and activated forms of phosphorylase kinase was carried out. The enzyme was activated by incubation in alkaline medium (pH 8.5), by phosphorylation with cAMP-dependent protein kinase and by limited proteolysis. The comparative analysis was based on the use of hydrophobic chromatography on phenyl-sepharose and electrophoresis in polyacrylamide gel density gradient. Activation of the enzyme was accompanied by separation of a low molecular weight component (Mr about 17 000). Using chromatography on phenyl-sepharose, this low molecular weight protein was obtained in a homogeneous state. It was found that the properties of the protein are close to those of calmodulin. The presence of calmodulin in phosphorylase kinase preparations was judged upon by the activation of the calmodulin-dependent form of phosphodiesterase. The boiled and subtilisin-treated kinase activates phosphodiesterase in the same way as does bovine brain calmodulin. The experimental results suggest that the delta-subunit is a protein inhibitor of the enzyme.
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PMID:[The role of calmodulin (delta-subunit) in the activation of phosphorylase kinase from rabbit skeletal muscles]. 301 Nov 26

The activation of phosphorylase kinase during limited proteolysis by subtilisin was studied. It was shown that phosphorylase kinase undergoes rapid activation and its activity remains unchanged throughout a prolonged incubation. Electrophoresis in the presence of Na-SDS revealed a rapid decomposition of the alpha-subunit and a gradual disappearance of the beta-subunit; the protein molecule was shown to be composed of the degradation products of alpha- and beta-subunits with different molecular weights and unchanged proteolysis of the gamma-subunit. The phosphorylase kinase hydrolysate was separated using chromatography on a cellulose phosphate column. The active protein fraction contains a new form of phosphorylase kinase with a low molecular weight (approximately 80 000) which is insensitive to Ca2+. The subtilisin-activated phosphorylase kinase does not affect the activity of phosphodiesterase from cyclic nucleotides.
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PMID:[Properties of phosphorylase kinase activated by subtilisin]. 701 93

YfkN isolated from the culture supernatant of Bacillus subtilis in the exponential phase of growth is a protein of 143.5 kDa that derives from a putative large precursor of 159.6 kDa processed at both the N- and C-terminal ends. Pulse-chase experiments indicated that the release occurs slowly with a half-time longer than 30 min, suggesting that the event is coupled with wall turnover. YfkN exhibits 2',3' cyclic nucleotide phosphodiesterase, 2' (or 3') nucleotidase and 5' nucleotidase activities. In vitro the protein is reduced by subtilisin digestion to a shorter polypeptide (68 kDa), displaying phosphodiesterase activity but devoid of any 5'nucleotidase activity. This proteolytic processing led us to localize the potential active sites of the various nucleotidase activities. When bacteria were grown in low phosphate medium, the exocellular production of the enzyme was enhanced, suggesting that it plays a role in phosphate metabolism. Comparison with nucleotidase databases suggests that yfkN resulted from gene fusion.
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PMID:Purification and characterization of YfkN, a trifunctional nucleotide phosphoesterase secreted by Bacillus subtilis. 1468 30

Invertebrate intracellular hemocyte signaling pathways affecting cellular-antigen responses, although defined for molluscs and some arthropods including dipteran insects, is less known for lepidopterans. Hemocytic-antigen responses of the arboreal pest lepidopteran Malacosoma disstria are linked to cAMP-dependent protein kinase A implicating cAMP in cellular hemocyte immune responses. The purpose in the present study was to determine intracellular cAMP effects on larval M. disstria hemocytes adhering to slides and bacteria. Altering adenylate cyclase and phosphodiesterase activities as well as cAMP levels in vitro and in vivo changed hemocyte responses to antigens. Quiescent hemocytes had high cAMP levels due to adenylate cyclase activity and possibly low phosphodiesterase (type 4) activity. Antigen contact diminished hemocytic cAMP levels. Inhibiting adenylate cyclase increased hemocyte-antigen and hemocyte-hemocyte adhesion, the latter producing nodules in vivo without bacterial antigens. Inhibiting phosphodiesterase type 4 produced the reverse effects. Pharmacologically increasing intracellular cAMP in attached hemocytes caused many of the cells to detach. Diminished intracellular cAMP changed hemograms in vivo in bacteria-free larvae comparable to changes induced by the bacterium, Bacillus subtilis, by producing nodules. Lowering cAMP enhanced also the removal of Xenorhabdus nematophila and B. subtilisin vivo.
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PMID:Innate hemocyte responses of Malacosoma disstria larvae (C. Insecta) to antigens are modulated by intracellular cyclic AMP. 1945 31