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)

Calmodulin-dependent phosphodiesterase was purified to apparent homogeneity from the total calmodulin-binding fraction of bovine heart in a single step by immunoaffinity chromatography. The isolated enzyme had significantly higher affinity for calmodulin than the bovine brain 60-kDa phosphodiesterase isozyme. The cAMP-dependent protein kinase was found to catalyze the phosphorylation of the purified cardiac calmodulin-dependent phosphodiesterase with the incorporation of 1 mol of phosphate/mol of subunit. The phosphodiesterase phosphorylation rate was increased severalfold by histidine without affecting phosphate incorporation into the enzyme. Phosphorylation of phosphodiesterase lowered its affinity for calmodulin and Ca2+. At constant saturating concentrations of calmodulin (650 nM), the phosphorylated calmodulin-dependent phosphodiesterase required a higher concentration of Ca2+ (20 microM) than the nonphosphorylated phosphodiesterase (0.8 microM) for 50% activity. Phosphorylation could be reversed by the calmodulin-dependent phosphatase (calcineurin), and dephosphorylation was accompanied by an increase in the affinity of phosphodiesterase for calmodulin.
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PMID:Phosphorylation and characterization of bovine heart calmodulin-dependent phosphodiesterase. 164 4

Calmodulin-like activity has been reported for the first time in mycobacterial species, namely Mycobacterium tuberculosis BCG and M. smegmatis ATCC 14468. The activity was mainly located in the soluble fraction of the mycobacterial cells, Radioimmunoassay revealed maximum levels of calmodulin in young growing cells (early logarithmic phase of growth). Calmodulin-dependent phosphodiesterase activation assay revealed low activity (22%) of partially purified calmodulin either due to insufficient amount of calmodulin to activate phosphodiesterase or due to the presence of some factors interfering with the assay. Calmodulin antagonists, viz. trifluoperazine and phenothiazine, significantly inhibited the 32Pi incorporation into mycobacterial phospholipids. Similar inhibition was observed when EGTA (which removes calcium) was added to the medium. Significant inhibition of 32Pi incorporation in the presence of calmodulin antagonists suggested the involvement of calmodulin in mycobacterial phospholipid metabolism.
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PMID:Calmodulin-like activity in mycobacteria. 166 96