title: The expression of free oligosaccharides in human seminal plasma.
abstract: Human seminal plasma is a complex mixture of proteins, glycoproteins, peptides, glycopeptides, and prostaglandins secreted by organs of the male reproductive tract. The components of this fluid have been implicated in the suppression of immune response, agonistic effects on sperm-egg binding, and promotion of successful implantation of the human embryo. Fractionation followed by biophysical analyses revealed that free oligosaccharides constitute a major component of the total glycoconjugates within seminal plasma. Significant findings of our analyses include the following: (i) the concentration of free oligosaccharides is 0.3-0.4 mg/ml; (ii) mono- and difucosylated forms of the disaccharide lactose are major components; (iii) many of the remaining oligosaccharides are also rich in fucose and carry Lewis(x) and/or Lewis(y) epitopes; (iv) a subset of the oligosaccharides express the reducing end sequence (GlcNAcbeta1-3/4Glc) not reported in human milk oligosaccharides; (v) oligosaccharides in seminal plasma exclusively express type 2 (Galbeta1-4GlcNAc) but not the type 1 sequences (Galbeta1-3GlcNAc) that predominate in human milk glycans; and (vi) the structural diversity of seminal plasma oligosaccharides is far less than human milk oligosaccharides. The agonistic effect of both fucose and fucosylated glycoconjugates on human sperm-egg binding in vitro suggests that fucosylated oligosaccharides may also promote fertilization in the female reproductive tract.
authors.affiliation: Department of Biological Sciences, Imperial College of Science, Technology, and Medicine, London SW7 2AY, United Kingdom.
authors.forename: Sara
authors.initials: S
authors.lastname: Chalabi
authors.forename: Richard L
authors.initials: RL
authors.lastname: Easton
authors.forename: Manish S
authors.initials: MS
authors.lastname: Patankar
authors.forename: Frank A
authors.initials: FA
authors.lastname: Lattanzio
authors.forename: Jamie C
authors.initials: JC
authors.lastname: Morrison
authors.forename: Maria
authors.initials: M
authors.lastname: Panico
authors.forename: Howard R
authors.initials: HR
authors.lastname: Morris
authors.forename: Anne
authors.initials: A
authors.lastname: Dell
authors.forename: Gary F
authors.initials: GF
authors.lastname: Clark
mesh_terms: D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000737:chemistry; D000939:Epitopes; D005643:Fucose / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D007785:Lactose / Q000737:chemistry; D007983:Lewis Blood Group Antigens / Q000737:chemistry; D016256:Lewis X Antigen; D008297:Male; D013058:Mass Spectrometry; D008895:Milk, Human / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis*; D012661:Semen / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D000939:Epitopes; D007983:Lewis Blood Group Antigens; D016256:Lewis X Antigen; C094162:Lewis Y antigen; D009844:Oligosaccharides; D005643:Fucose; D006026:Glycoside Hydrolases; D007785:Lactose