Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.16 (calcineurin)
 17,112 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cysteamine and propionitrile cause severe duodenal ulcers with perforation within 24-48 h after a single injection in rats. These animal models were used to gain insight into the early, preulcerogenic biochemical changes in the duodenal mucosa. The results indicate that a single sc injection of cysteamine and propionitrile induced dose- and time-dependent decreases in the activity of phosphoprotein phosphatase (PPPase) in homogenate and particulate fractions of rat duodenal mucosa. The decrease in enzyme activity was detectable 4 h after the injection of the ulcerogens, it was maximal at 12 h, and hardly detectable at 24 h. No effect on the enzyme activity was found under in vitro conditions. PPPase activity in the liver was not influenced by either cysteamine or propionitrile. Furthermore, the toxic but nonulcerogenic derivative of cysteamine ethanolamine had no effect on PPPase in the duodenum. Thus, the effect of the duodenal ulcerogens on PPPase activity was indirect and organ specific, related only to the target organ (i.e., duodenal mucosa). The effect of the drugs was also selective at the level of mucosal cells: both duodenal ulcerogens depleted protein and alkaline phosphatase but not lysosomal acid phosphatase. The decrease of PPPase activity could be a general property of the duodenal ulcerogens since it is independent of their effect on endogenous somatostatin.
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PMID:The influence of cysteamine and propionitrile on duodenal phosphoprotein phosphatase in rats. 289 91

A microcystin (MC)-Sepharose column was prepared by addition of 2-aminoethanethiol to the alpha, beta-unsaturated carbonyl of the N-methyldehydroalanine residue of MC-LR, followed by reaction of the introduced amino group with N-hydroxysuccinimide-activated CH-Sepharose. The MC-Sepharose bound protein phosphatase-1 (PP1) with high capacity and purified human PP1 gamma in one step from E. coli extracts. It was also used to purify forms of PP1 bound to myofibrils from skeletal muscle. Two of these comprised PP1 complexed to N-terminal fragments of the M-subunit which enhance its myosin phosphatase activity, while the third comprised PP1 and an N-terminal fragment of the glycogen-binding (G)-subunit.
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PMID:Purification of type 1 protein (serine/threonine) phosphatases by microcystin-Sepharose affinity chromatography. 798 18

Recent animal and bird deaths at several lakes in Ireland were indicative of possible cyanobacterial poisoning. Using protein phosphatase inhibition assays, microcystins (MCs) were identified in extracts of cyanobacteria from several lakes at concentrations ranging from 1.6 to 168 micrograms/g. This is the first report of MCs in Irish freshwaters. The protein phosphatase inhibition assay was used to screen fractions during HPLC purification of the MCs in cyanobacteria (Anabaena and Oscillatoria) and water samples from Corbally and Caragh Lakes. MC-LR, MC-HtyR, MC-FR, and MC-YR and 3 unidentified MCs of m/z values 1028.5, 981, 1042.7 were isolated from the Corbally sample; while the Caragh Lake sample contained largely MC-LR and MC-YR. A new microanalytical technique was developed for the confirmation of MCs which involved the derivatisation of the methyldehydroalanine group of MCs with 2-aminoethanethiol. Electrospray mass spectrometry of these products showed characteristic double-charged ions, and this novel technique was useful for differentiating MCs from co-eluting impurities in HPLC fractions of cyanobacterial extracts.
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PMID:First identification of microcystins in Irish lakes aided by a new derivatisation procedure for electrospray mass spectrometric analysis. 961 13