Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.37 (CNPase)
 539 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An improved method for the assay of cyclic nucleotide phosphodiesterases (CNPases) is described in which residual 3H-cAMP or 3H-cGMP is separated from products by chromatography on thin layers of PEI-cellulose. Comparison of CNPase activity in crude or purified kidney enzyme assayed by the PEI-cellulose method with a batch anion-exchange resin method showed serious underestimation of activity by the latter method. The batch method underestimated CNPase activity by 34-82%. The error was due to substantial binding of nucleosides (adenosine and guanosine) to the resin, which is assumed not to occur by those using this method.
J Chromatogr 1976 Dec 22
PMID:Comparison of batch and chromatographic assays of cyclic nucleiotide phosphodiesterases. 18 7

A myelin-related fraction (SN 4) was isolated from forebrain of 17- and 40-day-old rats. Fraction SN 4 was obtained as a supernatant in a slow speed differential centrifugation of a myelin fraction. In contrast to multilamellar myelin fraction, SN 4 consisted of small vesicular profiles of a mixture of single membranes and some triple-layered structures. All typical myelin components were found in the SN 4 fraction from adult rat brain but their relative proportion was different from that of myelin: Wolfgram protein, myelin glycoproteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase were increased, while basic proteins and proteolipid protein were decreased significantly. In contrast, the lipid composition appeared very similar to the one found in myelin. SN 4 from 17-day-old rat brains was essentially similar to that from adults, except that the major myelin glycoprotein was not enriched in comparison to myelin. Developmental changes found in myelin were also present in the SN 4 fraction. The specific radioactivity of the fucose-labeled major myelin glycoprotein was similar in SN 4 and in myelin. The particular composition of fraction SN 4 suggests that this material is not significantly contaminated by non-myelin-related membranes but rather supports the hypothesis that it could be enriched in a membrane representing a zone of transition during the formation of myelin and which is subjected to a remodelling of its protein components.
Brain Res 1977 Dec 09
PMID:Characterization of a myelin-related fraction (SN 4) isolated from rat forebrain at two developmental stages. 20 45

Purified Newcastle disease virus (NDV) virions possess 2',3'-cyclic nucleotide 2'-phosphohydrolase (2'-CNPase) and 2',3'-cyclic nucleotide 3'-phosphohydrolase (3'-CNPase) activities. These enzyme activities cannot be removed from the virion even after extensive purification by chromatography on controlled-pore glass. In the intact virion, the 3'-CNPase activity was stimulated by Triton X-100, while the 2'-CNPase activity was partially inhibited. We have prepared the NDV subunits and have shown that 3'-CNPase was associated exclusively with the viral nucleocapsid. In contrast, the 2'-CNPase activity was associated with both the envelope as well as the nucleocapsid. A threshold amount of both enzyme activities was detected in viral M protein.
Acta Virol 1990 Dec
PMID:Localization of 2',3'-decycling phosphodiesterases in the Newcastle disease virus virion. 198 76

The mouse 2',3'-cyclic-nucleotide 3'-phosphodiesterase gene was isolated from a mouse gene library. Restriction endonuclease mapping and DNA sequencing analysis revealed that this gene is about 6 kb long and is separated into three exons by two introns. The transcription initiation site was identified. The mouse cDNA of 2374 bp was obtained and used for the screening and analysis of the gene.
Biochem Biophys Res Commun 1989 Dec 29
PMID:Structure of mouse 2',3'-cyclic-nucleotide 3'-phosphodiesterase gene. 255 53

Clonal cell line D6P2T, subcloned from an ethylnitrosourea-induced tumor line D6 of the rat peripheral nervous system, has been characterized with particular attention to galactolipid metabolism. Galactosylcerebroside and sulfatide synthesis and expression on the cell surface are highly regulated in D6P2T cells by mechanisms involving serum- and cyclic AMP-mediated pathways. These cells also express 2',3'-cyclic nucleotide 3'-phosphohydrolase (Wolfgram protein W1a) and laminin. In contrast, myelin basic protein and antigen HNK-1 were not detected. Line D6P2T appears to be a semi-differentiated Schwann cell model, which offers interesting possibilities for studies of galactolipid synthesis, transport, and sorting.
J Neurochem 1987 Dec
PMID:Regulated galactolipid synthesis and cell surface expression in Schwann cell line D6P2T. 282 98

The distribution of calcium-activated neutral proteinase (CANP) activity was examined in the subcellular fractions of quaking and control mouse brain. The CANP activity was determined in purified myelin, cytosol and pellet (P2, consisting of nuclei, mitochondria and microsomes) fractions using [14C]azocasein as substrate. The enzyme activity in quaking brain was 1.3-fold greater than control. Fifty-seven percent of the control brain activity was in purified myelin compared to only 7% in quaking myelin. The specific activity of the control purified myelin was 4-fold greater than homogenate while that of the quaking was two-fold greater. In contrast, 51% of the quaking brain activity was present in cytosol compared to only 18% in the control. Triton X-100 greatly increased the control brain activity (10-fold) while the quaking brain activity was increased by only 1.2-fold. The total calcium content in the quaking brain was greatly elevated (6-fold) compared to control. Approximately 30% of the brain 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) activity was in quaking myelin while 77% of the CNPase activity in control brain was in myelin. These results suggest that in quaking brain much of the CANP is not incorporated into the myelin membrane and remains cytosolic.
Brain Res 1987 Dec 01
PMID:Distribution of calcium-activated neutral proteinase activity in quaking mouse brain: a subcellular study. 282 58

The composition of CNS myelin was investigated in rats adrenalectomized at day 14 and killed 7 days later, previously shown to result in a 25% reduction in the amount of bulk-isolated myelin and a 40% decrease in brain glycerol 3-phosphate dehydrogenase activity. The proportions of the major myelin proteins, as well as the specific activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase, were the same in the myelin from both adrenalectomized and control animals. The amount of total phospholipid and the proportions of individual phospholipids were also normal in myelin from the adrenalectomized animals. The amount of nonmyelin phospholipid in whole brain was unchanged by adrenalectomy. Labeling studies carried out 4 days after adrenalectomy of 14-day-old animals showed no change in the synthesis rates of the major myelin phospholipids as compared with the synthesis rate of nonmyelin phospholipids. Furthermore, incorporation of [1,(3)-14C]glycerol into the glycerol moiety of ethanolamine plasmalogen, which requires glycerol 3-phosphate dehydrogenase, was also normal, showing that the reduced oligodendroglial glycerol 3-phosphate dehydrogenase activity following adrenalectomy was not rate-limiting for myelin phospholipid synthesis.
J Neurochem 1985 Dec
PMID:Normal myelin composition and phospholipid synthesis in adrenalectomized rats with reduced brain myelin and glycerol 3-phosphate dehydrogenase activity. 299 97

The effect of insulin, proinsulin and crude pancreatic extract was studied in organotypic nerve tissue cultures, principally in relation to the development of myelin. Cultures were exposed to media supplemented with these substances beginning on the first day of explantation. By 4 days in vitro, there was a good neuritic outgrowth from all the fragments. That from the insulin and pancreatic extract-fed were more profuse and extended further than from the control group. By 8-12 days in vitro it was also possible to observe more myelinated axons in these treated groups. The pattern of changes in the myelin associated enzyme activity, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) paralleled the differential increase in myelination. Insulin-fed cultures showed a more rapid increase in CNPase activity, which, after 21 days in vitro reached a plateau about 30-50% over that of the controls. Cultures treated with pancreatic extract showed a similar pattern of increased activity, while in proinsulin-treated explants the activity was only significantly higher after 21 days in vitro. To study the effect of these substances on remyelination, well myelinated cultures were completely demyelinated by exposure to anti-white matter antiserum and were subsequently exposed to the same normal control or supplemented media. The amount of myelin and concomitantly the CNPase activity increased rapidly and in the same proportion between the various groups as was observed previously during primary myelination. Insulin as well as crude pancreatic extract and, to some extent, proinsulin demonstrated a marked effect on the time of onset and principally on the total amount of myelin developed by treated cultures as compared to those maintained in normal nutrient medium.
J Neurol Sci 1985 Dec
PMID:Effect of insulin, proinsulin and pancreatic extract on myelination and remyelination in organotypic nerve tissue in culture. 300 58

The metabolism of thyroxine (T4) and triiodothyronine (T3) in cultured glial cells was studied in situ. Cultures were prepared from fetal rat brain and grown for the last 4 days in a chemically defined medium (CDM). They contained astrocytes and oligodendrocytes as shown by the enzyme markers, glutamine synthetase and 2',3'-cyclic nucleotide phosphohydrolase. These cells contained high affinity (22-33 pM), limited capacity (120-230 fmol/mg DNA) nuclear receptors for T3. Cells incubated in situ with 50 pM [125I]T4 actively metabolized the hormone. The major iodothyronine produced was T3 (220-570 fmol/4 h/mg DNA). About 70% accumulated in the cells, the remainder was released into the medium. Within the cells, T3 was partly bound to the nuclear receptors (16.5-20 fmol/mg DNA). Reverse T3 (rT3) was a minor metabolite (30-45 fmol/4 h/mg DNA); it was almost completely released into the medium. The half-life of [125I]T3 (50 pM) was found to be about 15 h. These results show that, in situ, glial cell cultures containing astrocytes and oligodendrocytes grown in CDM actively deiodinate T4 to T3 and degrade T3 rather slowly.
Mol Cell Endocrinol 1986 Dec
PMID:Thyroid hormone metabolism by glial cells in primary culture. 380 6

A procedure was developed for the detection of 2',3'-cyclic nucleotide 3'-phosphohydrolase in myelin. This assay was sufficiently to detect the low levels of 2',3'-cyclic nucleotide 3'-phosphohydrolase in human erythrocytes. The 2',3'-cyclic nucleotide 3'-phosphohydrolase of human erythrocytes was determined to be exclusively associated with the inner (cytosolic) side of the membrane. Leaky ghosts and resealed ghosts were assayed for 2',3'-cyclic nucleotide 3'-phosphohydrolase (Ca2+/Mg2+)-ATPase, and acetylcholinesterase activity, and the 2',3'-cyclic nucleotide 3'-phosphohydrolase profile is the same as that of the (Ca2+/Mg2+)-ATP, an established inner membrane marker.
Biochim Biophys Acta 1981 Dec 18
PMID:Specific localization of 2',3'-cyclic nucleotide 3'-phosphohydrolase, (Ca2+/Mg2+)-ATPase, and acetylcholinesterase in human erythrocyte membrane. 611 15


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