title: Hypo-glycosylated human follicle-stimulating hormone (hFSH(21/18)) is much more active in vitro than fully-glycosylated hFSH (hFSH(24)).
abstract: Hypo-glycosylated hFSH(21/18) (possesses FSHβ(21) and FSHβ(18)bands) was isolated from hLH preparations by immunoaffinity chromatography followed by gel filtration. Fully-glycosylated hFSH(24) was prepared by combining the fully-glycosylated FSHβ(24) variant with hCGα and isolating the heterodimer. The hFSH(21/18) glycoform preparation was significantly smaller than the hFSH(24) preparation and possessed 60% oligomannose glycans, which is unusual for hFSH. Hypo-glycosylated hFSH(21/18) was 9- to 26-fold more active than fully-glycosylated hFSH(24) in FSH radioligand assays. Significantly greater binding of (125)I-hFSH(21/18) tracer than hFSH(24) tracer was observed in all competitive binding assays. In addition, higher binding of hFSH(21/18) was noted in association and saturation binding assays, in which twice as much hFSH(21/18) was bound as hFSH(24). This suggests that more ligand binding sites are available to hFSH(21/18) in FSHR than to hFSH(24). Hypo-glycosylated hFSH(21/18) also bound rat FSHRs more rapidly, exhibiting almost no lag in binding, whereas hFSH(24) specific binding proceeded very slowly for almost the first hour of incubation.
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA. Electronic address: george.bousfield@wichita.edu.
authors.forename: George R
authors.initials: GR
authors.lastname: Bousfield
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA.
authors.forename: Vladimir Y
authors.initials: VY
authors.lastname: Butnev
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA.
authors.forename: Viktor Y
authors.initials: VY
authors.lastname: Butnev
authors.affiliation: Biotechnology Core Facility, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Hiromasa
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford 0X1 3QU, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Harvey
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA.
authors.forename: Jeffrey V
authors.initials: JV
authors.lastname: May
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D043373:Follicle Stimulating Hormone, Human / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D015292:Glycoprotein Hormones, alpha Subunit / Q000737:chemistry* / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007457:Iodine Radioisotopes; D007986:Luteinizing Hormone / Q000737:chemistry* / Q000378:metabolism; D008358:Mannose / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D011869:Radioligand Assay; D051381:Rats; D011962:Receptors, FSH / Q000737:chemistry* / Q000378:metabolism; D020539:Sequence Analysis, Protein
chemical_list: D043373:Follicle Stimulating Hormone, Human; D015292:Glycoprotein Hormones, alpha Subunit; D007457:Iodine Radioisotopes; D011962:Receptors, FSH; D007986:Luteinizing Hormone; D008358:Mannose
keywords: FSH isoforms; FSHR; Oligosaccharide