Linked Life Data

6715364

Source:http://linkedlifedata.com/resource/pubmed/id/6715364

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1984-6-14
pubmed:abstractText
Parallel cytometric and fluorimetric analyses of the interaction of a fluoresceinated N-formyl hexapeptide (N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein, Nle = norleucine) with its receptors on human neutrophils are presented. The cytometric analyses take advantage of the ability of the fluorescence flow cytometer to discriminate free and receptor-bound ligand in a homogeneous real-time assay. The spectrofluorometric analysis relies on a high affinity antibody to fluorescein to discriminate free and bound ligand. We find that the number of receptors for formyl peptides on the surface of a resting cell is 53,000 +/- 13,000 (Kd approximately 0.6 +/- 0.2 nM). We use commercially available cytometric standards to calibrate the cytometer and we obtain similar values for the number of receptors. The temperature dependence of the kinetics of ligand-receptor interactions have been examined. The association rate constant varies from approximately 3 X 10(8) M-1 min-1 at 4 degrees C to approximately 10(9) M-1 min-1 at 37 degrees C (delta H approximately 8 kcal/mol). While ligand internalization is blocked at 4 degrees C, at 37 degrees C internalization proceeds at an initial rate of approximately 24% of the occupied receptors/min following a latency period of approximately 20-30 s. Intermediate rates and longer latency periods are found at 15 and 25 degrees C. Dissociation of the ligand is heterogeneous and depends both on the length of time of association and the temperature. After short periods of association, the ligand dissociates with t1/2 approximately 1-5 min. After longer periods (30 min at 15 degrees C or 100 min at 4 degrees C), but while the ligand-receptor complex remains on the cell surface, t1/2 increases to greater than 30 min. It appears that the ligand-receptor complex undergoes an alteration in affinity, with a time course at elevated temperatures, which parallels or lags behind the time course of the participation of the occupied receptors in cell activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5661-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
The dynamics of ligand-receptor interactions. Real-time analyses of association, dissociation, and internalization of an N-formyl peptide and its receptors on the human neutrophil.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't