title: Differences in glycosylation and sperm-egg binding inhibition of pregnancy-related glycodelin.
abstract: Glycodelin is a glycoprotein produced in many glands, particularly those of reproductive tissues. It appears as different glycoforms in amniotic fluid (glycodelin-A) and seminal plasma (glycodelin-S), but only glycodelin-A inhibits gamete adhesion. In the present study, glycodelin from secretory-phase endometrium, first-trimester pregnancy decidua, and midtrimester amniotic fluid was studied with respect to physicochemical properties, including glycosylation patterns and inhibitory activity of sperm-egg binding. Purified glycodelins from all these sources were similar in isoelectric focusing and in lectin immunoassays using lectins from Wisteria floribunda and Sambucus nigra. Likewise, the glycodelins inhibited sperm-egg binding in a dose-dependent manner, as measured by hemizona-binding assay. However, subtle quantitative physicochemical and biological differences were found between glycodelins from different sources as well as within the same tissue/fluid between different individuals. Differences were most pronounced between endometrial glycodelins from nonpregnancy and first-trimester pregnancy. The glycan structures studied by fast-atom bombardment mass spectrometry of individual amniotic fluid glycodelin-A samples also showed interindividual quantitative differences. In conclusion, glycodelins from different female reproductive tract tissues and amniotic fluid share substantial similarity, allowing all of them to be called glycodelin-A. However, these glycodelins exhibit quantitative physicochemical and functional differences between different sources and individuals.
authors.affiliation: Department of Obstetrics and Gynecology, Helsinki University Central Hospital, 00029 HUS, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Koistinen
authors.forename: Richard L
authors.initials: RL
authors.lastname: Easton
authors.forename: Philip C N
authors.initials: PC
authors.lastname: Chiu
authors.forename: Sara
authors.initials: S
authors.lastname: Chalabi
authors.forename: Mervi
authors.initials: M
authors.lastname: Halttunen
authors.forename: Anne
authors.initials: A
authors.lastname: Dell
authors.forename: Howard R
authors.initials: HR
authors.lastname: Morris
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: Markku
authors.initials: M
authors.lastname: Seppala
authors.forename: Riitta
authors.initials: R
authors.lastname: Koistinen
mesh_terms: D000328:Adult; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D000071816:Glycodelin; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D006031:Glycosylation; D006801:Humans; D007118:Immunoassay; D007525:Isoelectric Focusing; D037102:Lectins; D011134:Polysaccharides / Q000378:metabolism; D011247:Pregnancy / Q000502:physiology*; D011257:Pregnancy Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D016622:Silver Staining; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013084:Sperm-Ovum Interactions / Q000502:physiology*
chemical_list: D000071816:Glycodelin; D006023:Glycoproteins; D037102:Lectins; C045246:PAEP protein, human; D011134:Polysaccharides; D011257:Pregnancy Proteins