Linked Life Data

6269658

Source:http://linkedlifedata.com/resource/pubmed/id/6269658

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1981-12-21
pubmed:abstractText
A 33,000 g supernatant from human platelets showed a biphasic heat inactivation curve at 45, 50 and 55 degrees C of the cAMP and cGMP phosphodiesterase. This could suggest the presence of two differently heat sensitive phosphodiesterases. However, a preparation heated for 30 min at 55 degrees C, where only the apparently thermostable form of the enzyme remained, still displayed the same characteristics as the starting material, i.e. two apparent Km values for cAMP, a cAMP specific activity lower at low protein concentration (less than 50 micrograms/ml) than at high protein concentration(greater than 100 micrograms/ml), and three peaks of activity upon linear sucrose density gradient. Moreover, a biphasic inactivation curve was again observed after a second heat treatment. These results demonstrated that the heat effect is not a simple protein denaturation of one of two independent species. A study at different temperatures of the profile of the cAMP phosphodiesterase upon sucrose gradient demonstrated that the dissociated form was predominant at high temperature whereas lower temperature favored the associated form. During heat treatment, the dissociated form is at first denatured and this leads to a shift in the equilibrium between the associated and dissociated forms of the phosphodiesterase in favor of the dissociated form. From the overall results, one can draw a model for phosphodiesterase regulation by dissociation-reassociation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0300-9084
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
603-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
3',5' Cyclic nucleotide phosphodiesterase from human platelets: effect of heat upon the multiple forms and their interconversion.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't