title: Crystal structure of human chorionic gonadotropin.
abstract: The three-dimensional structure of human chorionic gonadotropin shows that each of its two different subunits has a similar topology, with three disulphide bonds forming a cystine knot. This same folding motif is found in some protein growth factors. The heterodimer is stabilized by a segment of the beta-subunit which wraps around the alpha-subunit and is covalently linked like a seat belt by the disulphide Cys 26-Cys 110. This extraordinary feature appears to be essential not only for the association of these heterodimers but also for receptor binding by the glycoprotein hormones.
authors.affiliation: Department of Chemistry, University of Glasgow, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Lapthorn
authors.forename: D C
authors.initials: DC
authors.lastname: Harris
authors.forename: A
authors.initials: A
authors.lastname: Littlejohn
authors.forename: J W
authors.initials: JW
authors.lastname: Lustbader
authors.forename: R E
authors.initials: RE
authors.lastname: Canfield
authors.forename: K J
authors.initials: KJ
authors.lastname: Machin
authors.forename: F J
authors.initials: FJ
authors.lastname: Morgan
authors.forename: N W
authors.initials: NW
authors.lastname: Isaacs
mesh_terms: D000595:Amino Acid Sequence; D002236:Carbohydrate Conformation; D006063:Chorionic Gonadotropin / Q000737:chemistry* / Q000378:metabolism; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D003553:Cystine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D006023:Glycoproteins / Q000737:chemistry; D006133:Growth Substances / Q000737:chemistry; D006728:Hormones / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D011974:Receptors, LH / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D004220:Disulfides; D006023:Glycoproteins; D006133:Growth Substances; D006728:Hormones; D011974:Receptors, LH; D003553:Cystine