The surface of alpha-subunit loop 1 distant from the subunit interface is exposed in the hCG lutropin receptor complex.
Interactions of the placental glycoprotein hormone human choriogonadotropin (hCG) with lutropin receptors (LHR) are required for maintenance of early pregnancy. Knowledge of how hCG interacts with LHR is useful for understanding the mechanism of receptor function, an issue of considerable debate. A large surface of hCG remains exposed after the hormone binds the LHR and can be readily detected with monoclonal antibodies. Here we show that the surface of hCG alpha-subunit loop 1 furthest from the beta-subunit interface can also be recognized by a monoclonal antibody when hCG is bound to the LHR. This extends the area of hCG known to be exposed in the hormone receptor complex, an observation that further restricts models of hCG-LHR interaction.
Department of OBGYN, UMDNJ-Robert Wood Johnson (Rutgers) Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA.
R V
RV
Myers
Y
Y
Wang
W R
WR
Moyle
D000911:Antibodies, Monoclonal / Q000276:immunology; D001665:Binding Sites; D006063:Chorionic Gonadotropin / Q000737:chemistry* / Q000276:immunology; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008958:Models, Molecular; D011247:Pregnancy; D021122:Protein Subunits; D011974:Receptors, LH / Q000737:chemistry*; D013329:Structure-Activity Relationship
D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D007457:Iodine Radioisotopes; D021122:Protein Subunits; D011974:Receptors, LH