Human chorionic gonadotropin subunit beta (hCGβ)

Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone essential for maintaining pregnancy by stimulating progesterone production from the corpus luteum [1]. It consists of an alpha subunit and a unique beta subunit (hCGβ), the latter of which contains a distinctive C-terminal peptide (CTP) [1, 2]. This CTP is highly glycosylated and is not present in the closely related luteinizing hormone (LH), providing hCG with a significantly longer half-life [2]. Because of these properties, the CTP is utilized in biotechnology to create long-acting recombinant hormones, such as corifollitropin alfa, which requires less frequent administration than standard follicle-stimulating hormone [3]. Additionally, the CTP is a target for experimental vaccines in oncology and contraception, as hCGβ is often overexpressed in various cancers and is necessary for pregnancy [4].

Other names

Choriogonadotropin subunit betaCGBhCG-betaC-terminal peptide of hCG betaCTPhCG-CTP

The C-terminal peptide (CTP) of the hCG beta subunit acts as a pharmacokinetic modifier that extends the circulatory half-life of proteins through heavy O-glycosylation [2]. In therapeutic applications, it is fused to other hormones to reduce dosing frequency or used as a specific antigen in vaccines to induce antibodies that neutralize hCG or target hCG-secreting tumors [3, 4].