Localization and structural characterization of an oligosaccharide O‐linked to bovine PDC‐109 Quantitation of the glycoprotein in seminal plasma and on the surface of ejaculated and capacitated spermatozoa

Abstract

PDC-109 (13 kDa) is the most abundant component, and the major heparin-binding protein, of bovine (Bos taurus) seminal plasma. Here, we show that PDC-109 contains a single O-linked oligosaccharide (NeuNAc a(26)-Galp(l-3)-GalNAc-) attached to Thr". Immunoquantitation of PDC-109 indicates that its concentration in seminal plasma is 15-20 mg/ml. Though PDC-109 is not present on epididymal sperm, ejaculated spermatozoa on average are coated with (9.5 f 0.3) x IO6 molecules of PDC-109/tell. This value remained constant in swim-up sperm and decreased to (7.7 + 0.4) x lO%permatozoon after incubation for 24 h in capacitation medium at 39°C. These data substantiate the hypothesis that PDC-109 may be one of the seminal plasma components that enhance the fertilizing capacity of bull spermatozoa upon interaction with heparin-like glycosaminoglycans present in the female genital tract.

Conformational Features and Thermal Stability of Bovine Seminal Plasma Protein PDC‐109 Oligomers and Phosphorylcholine‐Bound Complexes

“…Amide I' band-resolution by Fourier-self-deconvolution showed bands at 1678, 1666, 1646, 1631, and 1611 cm-', the latter probably due to the aniide-containing carbohydrates (Calvete et al, 1994). The result of the fitting into Lorenztian bands is shown under the evolvent in Fig.…”

“…BSP-A, has the same polypeptide chain as BSP-A, but is 0-glycosylated at Thrll (Calvete et al, 1994;Gerwig et al, 1996). BSP-A,/A,, collectively termed PDC-109 (Esch et al, 1983) and major protein (Scheit et al, 1988), is the most abundant protein of bull seminal plasma, where its concentration reaches 15-20 mg/ml (Calvete et al, 1994).…”

The structure of the O‐linked carbohydrate chain of bovine seminal plasma protein PDC‐109 revised by 1H‐NMR spectroscopy A correction

“…PDC-109 has a single 0-glycosylated residue (threonine 11) [4]. Carbohydrate composition, mass spectrometric, and lectin mapping analyses suggested the NeuSAc(a2-6)-Gal@-3)-GalNAc structure for the carbohydrate chain of bovine PDC-109 [4]. Here, we report the revision of the oligosaccharide structure of PDC-109 after IH-NMR spectroscopic analysis.…”

“…It possesses heparin-and phosphorylcholine-binding activities [3] and coats the spermatozoa surface at ejaculation [4], enhancing their fertilizing capability [5]. PDC-109 has a single 0-glycosylated residue (threonine 11) [4].…”

“…It possesses heparin-and phosphorylcholine-binding activities [3] and coats the spermatozoa surface at ejaculation [4], enhancing their fertilizing capability [5]. PDC-109 has a single 0-glycosylated residue (threonine 11) [4]. Carbohydrate composition, mass spectrometric, and lectin mapping analyses suggested the NeuSAc(a2-6)-Gal@-3)-GalNAc structure for the carbohydrate chain of bovine PDC-109 [4].…”