Plasma membrane receptor for beta-lactoglobulin and retinol-binding protein in murine hybridomas.
The aim of the present work was to study the binding of [125I]-BLGA (beta-lactoglobulin variant A) to the plasma membrane fraction of hybrid cells. This binding increased as a function of time with on-rate and off-rate constant at 4.47 +/- 0.18 x 10(6) M-1 min-1 and 0.17 +/- 0.07 min-1, respectively (n = 3). The saturation study showed a single binding site type corresponding to a Kd at 8.26 +/- 2.98 nM and 14.02 +/- 2.61 x 10(12) sites per mg of the plasma membrane protein (n = 3). Competitive of binding BLGA was observed with BLGA, complexed with retinol and also with RBP (retinol-binding protein). Gel filtration of [125I]-BLGA incubated with Triton X-100 solubilized membrane showed the formation of a ligand-receptor complex. Cross-linking of the tracer to plasma membrane showed a complex with a M(r) at 69 kDa, suggesting a receptor M(r) of 51 kDa, as seen by autoradiography of SDS-PAGE.
Mansouri
A
A
Laboratoire de Biochimie Cellulaire et Moléculaire en Nutrition, EP CHRS 616, Université H. Poincaré, Nancy, France.
Guéant
J L
JL
Capiaumont
J
J
Pelosi
P
P
Nabet
P
P
Haertlé
T
T
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism*; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006825:Hybridomas / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007782:Lactoglobulins / Q000378:metabolism*; D051379:Mice; D017830:Octoxynol; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012177:Retinol-Binding Proteins / Q000378:metabolism*; D054839:Retinol-Binding Proteins, Plasma; D012995:Solubility; D014801:Vitamin A / Q000378:metabolism
D003432:Cross-Linking Reagents; D007457:Iodine Radioisotopes; D007782:Lactoglobulins; D011956:Receptors, Cell Surface; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A; D017830:Octoxynol