Heterogencity of beta-hCG molecule: What is nicked & free beta hCG ??:--The pregnancy hormone human chorionic gonadotropin (hCG) and its free subunits (hCG alpha, hCG beta) are produced in the male reproductive tract and found in high concentrations in seminal fluid, in particular hCG alpha. This study aimed to elucidate changes in peptide hormone profiles in patients showing abnormal semen analyses and to determine the genuineness of the highly abundant hCG alpha.What is the different molecular structure of beta HCG?? What are phantom hCG molecules??  Ans:-During pregnancy, A) In serum = the α/β-heterodimer hCG is present in vast  excess in serum, B) but in urine it is present as  hCGβ/hCG βcf (hCGβ core fragment) in excess , but C) in seminal plasma, the subunit hCGα was by far the most prominent marker of the hCG molecular family, with concentrations as high as that found during pregnancy in extraembryonic coelomic fluid, and approximately 10,000-fold higher than in normal male serum. (Ackn-Reproductive Biology and Endocrinology

Decreased levels of genuine large free hCG alpha in men presenting with abnormal semen analysis

Christoph Zenzmaier)

CGβ and holo-hCG concentrations were found to be 1000-fold and 10,000-fold less than hCGα, whereas hCGβcf levels were mostly undetectable in seminal plasma .

Figure 1

Schematic depiction of the molecular structures of the cystine knot growth factor hCG and of hCG-variants. hCG consists of an α-subunit (hCGα) with 92 amino acids (aa) in length non-covalently linked to the hCGβ-subunit (145 aa). Nicked hCG (hCGn) and nicked hCGβ (hCGβn) contain nicks in the region of aa hCGβ44-48 and rarely around aa 77 of hCGβ. The most important metabolic product of hCG is the hCGβ core fragment (hCGβcf), which is composed of two peptides encompassing aa hCGβ6-40 and 55 to 92 covalently linked. The hCG-unique carboxyl-terminal peptide (CTP) is clipped and truncated hCG and hCGβ variants are generated (-CTPhCG and -CTPhCGβ). There are a multitude of glycosylation variants involving both N-glycosylated (hCGα aa 52 & 78, hCGβ aa 13 & 30) and O-glycosylated carbohydrate antennae (hCGβ aa Ser 121, 127, 132, 138) Reproductive Biology and Endocrinology

Decreased levels of genuine large free hCG alpha in men presenting with abnormal semen analysis

Christoph Zenzmaier

The findings indicate a pathophysiological relevance of hCG, particularly its free alpha subunit, in spermatogenesis. The alternative glycosylation pattern on the free large hCG alpha in seminal plasma might reflect a modified function of this subunit in the male reproductive tract

In the present study, the local profile of endocrine parameters, i.e. hCG-like substances and the family of protein hormones prolactin (hPRL), growth hormone (GH) and placental lactogen (PL), was analyzed in seminal plasma of men with abnormal semen analysis findings and compared to normozoospermic men to clarify a possible pathophysiological role of