Gonadotropins and the Importance of Glycosylation

A semi-automated hybrid HPLC-MS approach for in-depth characterization of intact non-covalent heterodimer glycoforms of gonadotropin biopharmaceuticals

“…S21). It is known that O-glycosylation and a higher degree of sialylation increases the serum half-life of the drug products [13,[15][16][17], thus from a O-glycosylation perspective it can be assumed that Ovitrelle® would be more stable than Pregnyl® in the blood circulation, but from a sialylation point of view Pregnyl® would have a longer serum half-life time. Moreover, Pregnyl® showed more impurities than Ovitrelle® (Fig.…”

“…Even if clinical studies have been conducted to assess the biological activity of urinary in comparison to recombinant biopharmaceuticals [11,12], the knowledge on how protein glycosylation influences the efficacy of the drug product is still limited [2,13,14]. It is known that the presence of O-glycans and/or terminally sialylated glycans increases half-life in circulation [13,[15][16][17] and that the folding of the subunit in the non-covalent heterodimer is facilitated by the presence of glycosylation [13].…”

“…Even if clinical studies have been conducted to assess the biological activity of urinary in comparison to recombinant biopharmaceuticals [11,12], the knowledge on how protein glycosylation influences the efficacy of the drug product is still limited [2,13,14]. It is known that the presence of O-glycans and/or terminally sialylated glycans increases half-life in circulation [13,[15][16][17] and that the folding of the subunit in the non-covalent heterodimer is facilitated by the presence of glycosylation [13]. The receptor-binding affinity and signal transduction are also affected by the glycosylation state of the gonadotropins: gonadotropins deglycosylated at the N52 of the alpha subunits showed an increased affinity for the receptor but a reduced stimulation of the cAMP signaling, resulting in reduced biological activity [14].…”

Identification and Relative Quantification of hFSH Glycoforms in Women’s Sera via MS–PRM-Based Approach

“…Hormone binding implies conformational changes of the FSHR that transduce the signal via direct protein interactions at the plasma membrane, resulting in a cascade of biochemical reactions that constitute an intertwined complex signaling network [4,5]. Four naturally human FSH (hFSH) glycovariants have been identified, which differ in their glycosylation [6][7][8]. In all four glycovariants the α-subunit's N-glycan sites (Asn-52 and Asn-78) are always glycosylated, whereas the N-glycosylation sites (Asn-7 and Asn-24) occurring within the β-subunit can be (i) both glycosylated, (ii) mixed (one glycosylated) or (iii) non-glycosylated [6,[9][10][11].…”