Linked Life Data

6114747

Source:http://linkedlifedata.com/resource/pubmed/id/6114747

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1981-10-25
pubmed:abstractText
Treatment of hog gastric microsomes with the sulfhydryl reagent, thimerosal (ethylmercurithiosalicylate), produced differential effects on the K+-ATPase and the K+-stimulated p-nitrophenylphosphatase activities. For example, exposure to 2 mM thimerosal for 3 min severely reduced the activity of K+-stimulated ATPase, while K+-p-nitrophenylphosphatase activity was enhanced 2- to 3-fold. Higher concentration of thimerosal, or longer incubation times, also led to inhibition of K+-p-nitrophenylphosphatase. The activated state of p-nitrophenylphosphatase could be sustained by a 20-fold, or greater, dilution of treated membranes, and could be reversed by reduction of membrane SH groups by exogenous thiols. Significant activation of K+-p-nitrophenylphosphatase was not produced by p-chloromercuribenzene sulfonate, p-chloromercuribenzoate or mersalyl; however, ethyl mercuric chloride had qualitatively similar activity effects as thimerosal. Kinetics of K+-p-nitrophenylphosphatase for thimerosal-treated membranes were altered as follows: V increased; Km for p-nitrophenylphosphate unchanged for Ka for K+ increased. ATP, which is a potent inhibitor of K+-p-nitrophenylphosphatase activity in native membranes (KI approximately 200 microM). These data suggest that there are multiple SH groups which differentially influence the gastric K+-stimulated ATPase activity. Defined treatments with thimerosal are interpreted as an uncoupling of the K+-stimulated phosphatase component of the enzyme (for which p-nitrophenylphosphatase is a presumed model reaction). Such differential modifications can be usefully applied to the study of partial reactions of the enzyme and their specific role in the related H+-transport reaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
644
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
257-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Specific modification of gastric K+-stimulated ATPase activity by thimerosal.
pubmed:publicationType
Journal Article