Glycome complexity of human seminal plasma high molecular mass components: Evaluation of the contribution of acid-soluble glycoproteins/mucins and extracellular vesicles

This study was aimed at evaluation of the contribution of acid-soluble glycoproteins (ASG)/mucins and extracellular vesicles (EVs), yet unexplored components of human seminal plasma (hSP) to the complexity of its glycome. Gaining insight into the native presentation and distribution of glycans across hSP could help establish molecular environments supporting specific biological activities based on unique ligand capacities. Soluble and particulate fractions of hSP from healthy subjects were analyzed by gel filtration, electrophoresis, ion-exchange chromatography and a solid phase assay with immobilized charge-resolved glycospecies to test their reactivity with plant lectins, carbohydrate-binding antibodies and selected human lectins. Common O- and N-glycosylated species were detected on mixed or overlapped underlying protein scaffolds in both soluble and particulate fractions of hSP. Siaα2,6Gal and N-glycans were concentrated on EVs, whereas Siaα2,3Gal, T and Tn antigens were selectively associated with distinct glycospecies of ASG/mucins. Accessible ligands for the lectins, DC-SIGN and Siglec-9, were detected in all hSP components, but they preferentially bound to EVs glycospecies. Insight into the complexity of hSP glycans as recognition signals under normal physiological conditions could be of interest for regulation and possible modulation of its biological activity, as well as for biomarker potential related to male health. [Display omitted] •Seminal plasma glycans are selectively placed on its soluble and particulate fraction.•Siaα2,6Gal and N-glycans are concentrated on extracellular vesicles (EVs).•Siaα2,3Gal and short O-glycans are concentrated on mucins.•Endogenous lectins DC-SIGN and Siglec-9 preferentially bound to EVs.