Linked Life Data

94064

Source:http://linkedlifedata.com/resource/pubmed/id/94064

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1980-5-23
pubmed:abstractText
Broken cell preparations of WI-38 and SV40-transformed WI-38 (VA13) fibroblasts were used to compare the cyclic nucleotide phosphodiesterase activities of the two cell strains. The bulk of the cAMP or cGMP phosphodiesterase activity of WI-38 and VA13 homogenates was found in the 100,000 x g fibroblast supernatant fractions. WI-38 and VA13 soluble phosphodiesterase activities showed anomalous kinetic behavior with either cAMP or cGMP as the substrate. At low substrate concentrations, e.g., 0.1 muM, WI-38 supernatant fractions hydrolyzed cGMP much more rapidly than cAMP. At high substrate concentrations, e.g., 100muM, the same enzyme preparations degraded cAMP more than twice as fast as cGMP. In contrast, VA13 soluble phosphodiesterase activity catalyzed the hydrolysis of a wide range of cAMP and cGMP concentrations at similar rates. Phosphodiesterase activity in WI-38 supernatant fractions was generally more sensitive than that of the comparable VA13 enzyme activity to inhibition by MIX and papaverine. The cAMP phosphodiesterase activity of both WI-38 and VA13 supernatant preparations was decreased by cGMP in a concentration-dependent manner. cAMP was an effective inhibitor of cGMP hydrolysis by VA13 soluble phosphodiesterase activity. Yet, the cGMP phosphodiesterase activity of WI-38 supernatant fractions was only slightly reduced in the presence of cAMP. DEAE-cellulose chromatography of WI-38 and VA13 supernatant preparations revealed two major peaks of phosphodiesterase activity for each cell type. WI-38 peak I showed much greater activity with 1muM cGMP than with 1muM cAMP and appeared to be composed of two different phosphodiesterase activities. WI-38 peak Ia included phosphodiesterase activity which could be stimulated by boiled, dialyzed fibroblast homogenates while WI-38 peak Ib coincided with column fractions which contained most of the cyclic GMP hydrolytic activity. VA13 peak I phosphodiesterase activity was eluted from DEAE cellulose columns at the same ionic strength as WI-38 peak Ia and hydrolyzed these two substrates at nearly identical rates. This enzyme activity was also increased in the presence of boiled, dialyzed fibroblast preparations. Peak II phosphodiesterase activities from both WI-38 and VA13 fibroblasts were relatively specific for cAMP as the substrate. Phosphodiesterase activity with the properties of WI-38 peak Ib was not isolated from VA13 supernatant fractions. These results suggested that the dissimilar patterns of cAMP accumulation in WI-38 and VA13 cultures may be at least partially related to different phosphodiesterase activities in the normal and the transformed fibroblasts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0095-1544
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
449-61
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Dissimilar cyclic nucleotide phosphodiesterase activities in subcellular fractions from normal and SV40-transformed WI-38 fibroblasts.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.