1QFW

TERNARY COMPLEX OF HUMAN CHORIONIC GONADOTROPIN WITH FV ANTI ALPHA SUBUNIT AND FV ANTI BETA SUBUNIT

Summary for 1QFW

• Entry DOI: 10.2210/pdb1qfw/pdb
• Descriptor: GONADOTROPIN ALPHA SUBUNIT, GONADOTROPHIN BETA SUBUNIT, ANTIBODY (ANTI ALPHA SUBUNIT) (LIGHT CHAIN), ... (7 entities in total)
• Functional Keywords: glycoprotein hormone, stimulation of production of progesterone, fvs specifically directed against alpha and beta subunit, immune system
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 6
• Total formula weight: 77152.53

Authors

Tegoni, M.,Spinelli, S.,Cambillau, C. (deposition date: 1999-04-15, release date: 2000-04-26, Last modification date: 2024-10-16)

Primary citation

Tegoni, M.,Spinelli, S.,Verhoeyen, M.,Davis, P.,Cambillau, C.
Crystal structure of a ternary complex between human chorionic gonadotropin (hCG) and two Fv fragments specific for the alpha and beta-subunits.
J.Mol.Biol., 289:1375-1385, 1999

PubMed Abstract: Human chorionic gonadotropin (hCG), is a placental hormone which exerts its major effect by stimulating progesterone production, crucially sustaining the early weeks of pregnancy. Detection of hCG with specific monoclonal antibodies (mAbs) has become the chosen means for pregnancy diagnosis. We have used antibody Fv fragments derived from two high-affinity mAbs, one against the alpha and the other against the beta-hCG subunit to enable the crystallisation of intact or desialylated hCG. Crystals of a ternary complex composed of Fv anti-alpha/hCG/Fv anti-beta were found to diffract to 3.5 A resolution, and the structure was solved by molecular replacement. In the crystal, the two Fvs keep hCG as in a molecular cage, providing good protein-protein contacts and leaving enough space for the saccharides to be accommodated in the cell solvent. The two Fvs were found not to interact directly through their complementary-determining regions with the hCG saccharides, but only with the protein. The hCG structure in the ternary complex was very close to that of the HF partially deglycosylated hormone, thus indicating that neither the saccharides nor the Fvs had any substantial influence on hormone structure.

PubMed: 10373373
DOI: 10.1006/jmbi.1999.2845

Experimental method

X-RAY DIFFRACTION (3.5 Å)