Recombinant Human CG alpha/beta (HCG) Heterodimer Protein

• Reactivity: Hu
• Applications: Bioactivity

Recombinant Human CG alpha/beta (HCG) Heterodimer Protein Summary

• Details of Functionality: Measured by its ability to induce cAMP accumulation in MLTC‑1 mouse Leydig tumor cells. Rebois, R.V. et al. (1982) J. Cell Biol. 94:70. The ED₅₀ for this effect is 0.07-0.42 ng/mL.
• Source: Chinese Hamster Ovary cell line, CHO-derived human Chorionic Gonadotropin alpha/beta (HCG) protein
  

  Human CG beta (Ser21-Gln165) Accession # P01233

  Human CG alpha (Ala25-Ser116) Accession # P01215
  N-terminus	C-terminus

• Accession #: P01233 (CG beta ) & P01215 (CG alpha )
• N-terminal Sequence: Ser21 (CG beta ) & Ala25 (CG alpha )
• Structure / Form: Noncovalently-linked heterodimer
• Protein/Peptide Type: Recombinant Proteins
• Gene: CGB3
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.01 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 15.5 kDa (CG beta ) & 10.2 kDa (CG alpha ).
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 27-32 kDa & 20-22 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 100 μg/mL in PBS containing at least 0.1% human or bovine serum albumin.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human CG alpha/beta (HCG) Heterodimer Protein

• CGB
• CGB5
• CGB7
• CGB8
• CG-beta
• Choriogonadotropin subunit beta 3
• Choriogonadotropin
• Chorionic gonadotrophin chain beta
• Chorionic Gonadotropin alpha/beta
• Chorionic gonadotropin beta 3 subunit
• chorionic gonadotropin beta chain
• chorionic gonadotropin beta subunit 3
• chorionic gonadotropin chain beta
• hCGB
• LHB
• luteinizing hormone beta subunit

Background

HCG (human chorionic gonadotropin) is a member of the glycoprotein hormone (GPH) family within the cystine knot growth factor superfamily (1‑5). It is a heterodimer of a 23‑32 kDa unique subunit, CGb, with a 14‑22 kDa alpha subunit, CGa (common glycoprotein hormone alpha) that is shared with GPH family members lutropin (LH), follitropin (FSH) and thyroid stimulating hormone (TSH) (1, 2). CGb occurs only in higher primates, while the most closely related hormone, LHb, is expressed in all mammals (6). Human CGb and LHb share a receptor, LH/CG‑R or LHR, and show 86% aa sequence identity between aa 21 and 133, before diverging into a 32 aa, highly O‑glycosylated (CGb) or 8 aa (LHb) C‑terminal tail (2). Mature human CGa shares 69%‑73% aa identity with dog, rabbit, rat, mouse, cow, sheep, pig, cat and horse CGa. Each subunit form a cystine knot structure with three disulfide bridges (5). A “seat‑belt” loop of CGb wraps around CGa, stabilizing subunit non‑covalent association and conferring receptor selectivity (5). CGb is encoded by six clustered, nonallelic genes that encode identical, but differentially expressed, proteins (2, 7). HGC produced by cytotrophoblast cells in early pregnancy is hyperglycosylated and sialylated, increasing its acidity and half‑life (3, 4, 8). Forms with lower glycosylation are produced by syncytiotrophoblasts in continuing pregnancy, and in small amounts by the pituitary where it is also sulfated (4, 8). Free, variably glycosylated CGb subunits are also reported (3, 4). The primary role of HCG is to act as an autocrine factor to establish pregnancy and control placental growth and function. HCG has also been shown to induce the angiogenic factor, EG‑VEGF/PK1, and contribute to immune privilege by increasing circulating regulatory T cells and anti‑inflammatory cytokines IL‑10 and IL‑27, via cAMP signaling (9, 10). In addition to pregnancy, large amounts of HCG are produced in gestational trophoblastic diseases such as choriocarcinoma and hydatiform mole (3, 4). HCG may also be produced by ovarian and testicular germ cell tumors and advanced cancers that have dedifferentiated (3, 4).

1. Fiddes, J.C. and H.M. Goodman (1979) Nature 281:351.
2. Policastro, P. et al. (1983) J. Biol. Chem. 258:11492.
3. Stenman, U.H. et al. (2006) Human Reprod. Update 12:769.
4. Cole, L.A. (2012) Am. J. Cancer Res. 2:22.
5. Lapthorn, A.J. et al. (1994) Nature 369:455.
6. Maston, G.A. and M. Ruvolo (2002) Mol. Biol. Evol. 19:320.
7. Zimmerman, G. et al. (2012) Biol. Reprod. 86:1.
8. Kovalevskaya, G. et al. (2007) Mol. Cell. Endocrinol. 260-262:237.
9. Brouillet, S. et al. (2012) Cell. Mol. Life Sci. 69:1537.
10. Koldehoff, M. et al. (2011) J. Leukoc. Biol. 90:1017.

Bioinformatics

• Gene Symbol: CGB3
• Uniprot:
  • P01233 (CG beta ) & P01215 (CG alpha )()