BINDING OF HUMAN GM-CSF TO SYNTHETIC PEPTIDES OF THE ALPHA-SUBUNIT OFITS RECEPTOR

We have synthesized a series of peptides corresponding to portions of the extracellular domain of human granulocyte-macrophage colony stimul ating factor receptor alpha subunit (hGM-CSFR alpha). The sequences we re chosen according to the homology between hGM-CSFR alpha and the gro wth hormone receptor (GHR) and correspond-to the regions reported to f orm the binding site of the latter receptor. The peptides were examine d for their binding activity to hGM-CSF by affinity chromatography on resin-immobilized hGM-CSF and by a solid phase binding assay. Four pep tides endowed with hGM-CSF binding activity were identified and the po stulated homology between the binding sites of hGM-CSFR alpha and GHR was confirmed.