title: Histochemical detection of binding sites for human growth hormone using biotinylated ligand.
abstract: Recombinant human growth hormone was covalently linked to biotin via a six-carbon spacer arm. Biotinylation was confirmed by electrophoresis and mass spectrometry showed that approximately 50% of the hormone was monobiotinylated. The modified growth hormone (GH) was shown to bind to the GH receptor of IM9 human lymphoid cells with an affinity of 0.55 x 10(9) M-1. Bioactivity of biotinylated GH measured in the Nb2 bioassay was 53.9% that of unlabeled GH. GH binding sites on human IM9 cells were visualized histochemically with the biotinylated hormone, a technique that provides a means of identifying receptors for GH on target cells in vitro.
authors.affiliation: Department of Clinical Biochemistry, King's College Hospital, London, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Bentham
authors.forename: R
authors.initials: R
authors.lastname: Aplin
authors.forename: M R
authors.initials: MR
authors.lastname: Norman
mesh_terms: D000818:Animals; D001665:Binding Sites; D001710:Biotin; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D013006:Growth Hormone / Q000032:analysis* / Q000378:metabolism; D006651:Histocytochemistry / Q000379:methods*; D006801:Humans; D008024:Ligands; D008214:Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure; D008223:Lymphoma / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D013058:Mass Spectrometry; D051381:Rats; D011986:Receptors, Somatotropin / Q000032:analysis* / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D008024:Ligands; D011986:Receptors, Somatotropin; D001710:Biotin; D013006:Growth Hormone