Differences in glycosylation and sperm-egg binding inhibition of pregnancy-related glycodelin.
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.
Koistinen
Hannu
H
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, 00029 HUS, Finland.
Easton
Richard L
RL
Chiu
Philip C N
PC
Chalabi
Sara
S
Halttunen
Mervi
M
Dell
Anne
A
Morris
Howard R
HR
Yeung
William S B
WS
Seppala
Markku
M
Koistinen
Riitta
R
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*
D000071816:Glycodelin; D006023:Glycoproteins; D037102:Lectins; C045246:PAEP protein, human; D011134:Polysaccharides; D011257:Pregnancy Proteins