Differences in Glycosylation and Sperm-Egg Binding Inhibition of Pregnancy-Related Glycodelin

• Published in: Biology of reproduction 2003-11, Vol.69 (5), p.1545-1551
• Main Authors: KOISTINEN, Hannu, EASTON, Richard L, CHIU, Philip C. N, CHALABI, Sara, HALTTUNEN, Mervi, DELL, Anne, MORRIS, Howard R, YEUNG, William S. B, SEPPÄLÄ, Markku, KOISTINEN, Riitta
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Female; Fundamental and applied biological sciences. Psychology; Glycodelin; Glycoproteins - chemistry; Glycoproteins - metabolism; Glycoproteins - physiology; Glycosylation; Humans; Immunoassay; Isoelectric Focusing; Lectins; Mammalian male genital system; Morphology. Physiology; Polysaccharides - metabolism; Pregnancy - physiology; Pregnancy Proteins - chemistry; Pregnancy Proteins - metabolism; Pregnancy Proteins - physiology; Silver Staining; Spectrometry, Mass, Fast Atom Bombardment; Sperm-Ovum Interactions - physiology; Vertebrates: reproduction
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod.103.017830

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.