Linked Life Data

6235229

Source:http://linkedlifedata.com/resource/pubmed/id/6235229

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1984-9-17
pubmed:abstractText
Comparative measurements were carried out in order to evaluate the significance of intrinsic fluorescence transients with respect to various steps of the catalytic and transport cycle of sarcoplasmic reticulum ATPase. The enzyme can acquire three levels of intrinsic fluorescence. Level 1 (lowest fluorescence) is observed in the absence of Ca2+ and ATP. Level 2 (highest fluorescence) is induced by Ca2+ through a sequential mechanism including two binding steps interspaced by an isomerization step. This transition occurs more rapidly in the presence of ATP and produces enzyme activation. Level 3 (slightly higher fluorescence than level 1) is observed immediately upon ATP binding (or phosphorylation with Pi) in the absence of Ca2+. When ATP is added to the enzyme X calcium complex, the enzyme is rapidly phosphorylated and the bound calcium is translocated to a position which is protected from La3+ added to the medium. This initial phenomenon is followed by a slow isomerization of the phosphoenzyme which is revealed by a decrease of fluorescence intensity and produces calcium release inside the vesicles before hydrolytic cleavage of the phosphoenzyme. A reaction cycle is considered and subjected to analysis, based on three main enzyme states: E, in the absence of Ca2+; E', in the presence of Ca2+; and *E, subsequent to phosphorylation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9687-98
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
A comparative study of calcium transients by isotopic tracer, metallochromic indicator, and intrinsic fluorescence in sarcoplasmic reticulum ATPase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't