HCG (5000)

Human Chorionic Gonadotropin (hCG) - Research Grade Glycoprotein Hormone Molecular Profile: Human chorionic gonadotropin is a heterodimeric glycoprotein hormone consisting of non-covalently associated α and β subunits. The α-subunit contains 92 amino acids (~14.5 kDa), while the hormone-specific β-subunit contains 145 amino acids (~22.2 kDa) including a unique 24-amino acid carboxy-terminal peptide extension. Combined molecular weight: approximately 36,700 Da. Glycosylation (8 sites total: 2 N-linked on α-subunit, 2 N-linked and 4 O-linked on β-subunit) comprises 25-40% of molecular mass and confers extended serum half-life of 24-36 hours. CAS Registry Number: 9002-61-3. Mechanism of Action: hCG functions as a potent agonist of the luteinizing hormone/chorionic gonadotropin receptor (LHCGR), a rhodopsin-like family A G protein-coupled receptor. Receptor binding triggers Gαs protein coupling and adenylyl cyclase activation, generating cyclic AMP (cAMP). Elevated cAMP activates protein kinase A (PKA) and exchange protein directly activated by cAMP (EPAC), initiating phosphorylation cascades that regulate steroidogenic acute regulatory protein (StAR) expression and cholesterol mobilization. In Leydig cells, this cascade drives testosterone biosynthesis through sequential enzymatic conversions involving CYP11A1, HSD3B, CYP17A1, and HSD17B enzymes. hCG exhibits ~5-fold higher potency than LH for cAMP production (EC50 ~107 pM) with slower dissociation kinetics and biased agonism favoring cAMP/PKA over β-arrestin pathways. Research Applications: - LHCGR signaling pathway investigation and G protein-coupled receptor biology - Leydig cell steroidogenesis and acute testosterone production mechanisms - Corpus luteum function, luteinization, and progesterone synthesis regulation - HPG axis physiology, gonadotropin action, and reproductive endocrinology - Steroidogenic enzyme expression and cholesterol metabolism in gonadal tissues - Biased agonism and differential signal transduction compared to LH Product Specifications: - Purity: ≥95% (SDS-PAGE) - Appearance: White to off-white lyophilized powder - Solubility: Water and physiological buffers (PBS, HBSS) up to 1 mg/mL - Endotoxin: <1.0 EU/μg protein (LAL method) - Bioactivity: Verified by cAMP accumulation assay in LHCGR-expressing cells - Storage: -20°C lyophilized; -80°C reconstituted aliquots - Stability: Minimize freeze-thaw cycles (maximum 3 recommended) Laboratory Use Disclaimer: FOR RESEARCH USE ONLY. NOT FOR HUMAN OR VETERINARY USE. This product is intended solely for in-vitro laboratory research by qualified personnel. Not approved for therapeutic, diagnostic, or clinical applications. Handle using BSL-1 practices with appropriate personal protective equipment. Purchaser assumes all responsibility for regulatory compliance. Dispose according to institutional biosafety guidelines. Animal research requires IACUC approval; human subject research requires IRB approval.