Linked Life Data

3985153

Source:http://linkedlifedata.com/resource/pubmed/id/3985153

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 2
pubmed:dateCreated
1985-5-14
pubmed:abstractText
We evaluated Ca binding by highly purified luminal (L) and basolateral (BL) tubular membranes prepared from beef kidney. Ca binding was measured by using 45Ca and a rapid-filtration technique. After Ca uptake reached equilibrium, the vesicles were lysed and the amount of 45Ca retained in the membranes was considered the bound Ca. Ca binding in both membranes accounted for approx. 80% of total Ca uptake. Analysis of binding data by Scatchard plot revealed the presence of two distinct types of binding sites in both L and BL membranes. The high-affinity binding sites showed a similar affinity constant of 10(-5)M for both L and BL membranes, but the maximum number of binding sites was 0.75 and 1.6 nmol/mg protein, respectively. In contrast, the low-affinity binding sites were similar regarding affinity constant and maximum number of binding sites in the two membranes. In L and BL membranes, high-affinity binding sites were selective for Ca, as high concentrations of divalent cations were required to inhibit Ca binding. In both membranes Ca binding was inhibited by ruthenium red, LaCl3, and detergents, and it was stimulated by calmodulin inhibitors (trifluoperazine, calmidazolium), ionophore A-23187, and ATP. These results demonstrate that L and BL membranes possess high-affinity binding sites with different capacities but similar characteristics as regards affinity constant and stimulation and inhibition of binding. The data further demonstrate that most of Ca uptake by these membranes represents binding.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
248
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F472-81
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
High-affinity calcium binding sites in luminal and basolateral renal membranes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.