Glycodelin: a reproduction-related lipocalin.

Glycodelin, a human lipocalin, is a major endometrial protein with at least two differentially glycosylated isoforms. Glycodelin-A (GdA) is purified from human mid-trimester amniotic fluid, where it is secreted from the decidualized endometrium. Glycodelin-S (GdS) is synthesized in the male reproductive tract, mainly in the seminal vesicles, and secreted into seminal plasma. These two glycodelin isoforms, glycosylated in a completely different manner, serve as a good model for studying the effects of glycosylation on protein function and physicochemical properties. We have reviewed here the structure, expression and biological functions of glycodelin.