Falk, Werner and Harvath, L. and Leonard, E.J.
Only the chemotactic subpopulation of human blood monocytes expresses receptors for the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine.
Infection and immunity 36 (2), pp. 450-454.
Human peripheral blood monocytes comprise a subpopulation of 20 to 40% that is capable of responding to chemoattractants and a remaining subpopulation that cannot respond. We were able to obtain 99%-pure attractant-responsive monocytes by using a newly constructed separation chamber. The binding of the radioactive chemotactic peptide N-formylmethionyl-leucyl-[3H]phenylalanine to migrating and nonmigrating populations was then studied. The binding was saturable at room temperature in the presence of azide. Saturation occurred at 5 x 10(-8) M, and 50% of the maximal binding was obtained at 10(-8) M, the concentration that induced optimal chemotaxis. The nonmigrating monocytes did not bind the peptide under the same conditions, which shows that at least one reason for a nonresponsiveness to chemotaxin is apparently a lack of receptors. By Scatchard analysis we calculated an equilibrium dissociation constant ranging from 23 to 37 nM; the number of binding sites per cell ranged from 64,000 to 77,000. The binding was very rapid. Fifty percent of the optimal binding occurred at 3.5 min, and equilibrium was reached after 20 to 30 min. Chemotactic deactivation of the monocytes reduced the number of available binding sites by 60%.
|Institutions:|| Medicine > Lehrstuhl für Innere Medizin I|
|Methionine/analogs & derivatives||MESH|
|Receptors, Cell Surface/metabolism||MESH|
|Receptors, Formyl Peptide||MESH|
|Subjects:||600 Technology > 610 Medical sciences Medicine|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||20 Jul 2010 09:13|
|Last Modified:||20 Jul 2011 22:33|