Interaction of silkworm larvae expressed monomeric hM-CSF with its receptor on murine bone marrow derived macrophage.
Human macrophage colony-stimulating factor (hM-CSF) expressed in the silkworm larvae was monomeric. The nature of the interaction of iodinated monomeric M-CSF with murine bone marrow derived macrophage (BMM) was studied. On incubation with 2 nM [125I]M-CSF at 4 degrees C, approximately 90% of the maximal binding occurred within 15 min with a plateau around 1hr which then gradually declined. Scatchard plot analysis showed that the Kd for the monomeric M-CSF is 5.3 x 10(-10) M and the number of binding sites per cell is 4 x 10(4). Competition experiment indicated that cellular binding of the iodinated monomeric rhM-CSF was almost as effective as the native M-CSF. The results show that the interchain disulfide bond of M-CSF is not essential for the natural folding of active M-CSF.
Qiu
P
P
Department of Biochemistry, Nanjing University, P.R. China.
Xi
T
T
Zhu
J
J
Qin
J
J
Zhu
D
D
D000818:Animals; D001667:Binding, Competitive; D012831:Bombyx; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes; D007700:Kinetics; D007814:Larva; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008970:Molecular Weight; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D014162:Transfection
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor