Crystal structure of human chorionic gonadotropin.
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.
Lapthorn
A J
AJ
Department of Chemistry, University of Glasgow, UK.
Harris
D C
DC
Littlejohn
A
A
Lustbader
J W
JW
Canfield
R E
RE
Machin
K J
KJ
Morgan
F J
FJ
Isaacs
N W
NW
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
D006063:Chorionic Gonadotropin; D004220:Disulfides; D006023:Glycoproteins; D006133:Growth Substances; D006728:Hormones; D011974:Receptors, LH; D003553:Cystine