title: Roles of glycodelin in modulating sperm function.
abstract: Glycodelin is a glycoprotein with three well-defined isoforms. They are named as glycodelin-S, glycodelin-A and glycodelin-F. The three isoforms have similar protein core but different carbohydrate moieties. Glycodelin-S is abundant in the human seminal plasma. It suppresses sperm capacitation and in doing so, it maintains the spermatozoa in an uncapacitated state before they enter into the uterine cavity. Glycodelin-A is abundant in the amniotic fluid. It is also secreted from endometrial glands into uterine fluid and is produced by the fallopian tube. Glycodelin-A is the first endogenous glycoprotein that was found to inhibit the binding of spermatozoa to the zona pellucida. The immunosuppressive properties of glycodelin-A suggest that the molecule may protect the spermatozoa from immune attack in the maternal reproductive tract. Glycodelin-F was first found in the follicular fluid, hence its name. It also inhibits spermatozoa-zona pellucida binding. In addition, glycodelin-F suppresses progesterone-induced acrosome reaction, and may serve to prevent premature acrosome reaction. Preliminary findings suggest possible presence of yet another glycodelin isoform in the extracellular matrix of cumulus oophorus. Unlike glycodelin-A and -F, it stimulates spermatozoa-zona pellucida binding. In summary, different isoforms of glycodelin have different biological roles on sperm function, and they act in succession to contribute to the success of fertilization.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China. wsbyeung@hkucc.hku.hk
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: Kai-Fai
authors.initials: KF
authors.lastname: Lee
authors.forename: Riitta
authors.initials: R
authors.lastname: Koistinen
authors.forename: Hannu
authors.initials: H
authors.lastname: Koistinen
authors.forename: Markku
authors.initials: M
authors.lastname: Seppala
authors.forename: P C
authors.initials: PC
authors.lastname: Ho
authors.forename: Philip C N
authors.initials: PC
authors.lastname: Chiu
mesh_terms: D005260:Female; D005836:Genitalia, Female / Q000502:physiology; D000071816:Glycodelin; D006023:Glycoproteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008297:Male; D011257:Pregnancy Proteins / Q000235:genetics / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics / Q000502:physiology; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D000071816:Glycodelin; D006023:Glycoproteins; C045246:PAEP protein, human; D011257:Pregnancy Proteins; D020033:Protein Isoforms