Treatment of cervical mucus with lectins: effect on sperm migration

Treatment of midcycle human cervical mucus with the lectins Ulex europaeus agglutinin I (UE), wheat germ agglutinin (WGA), and peanut agglutinin (PA) did not alter the ability of spermatozoa to enter and migrate through the mucus. These lectins form glycoconjugates by binding to L-fucose (UE), N-acetylglucosamine and sialic acid (WGA), and D-galactose and D-galactose-(1-3)-D-N-acetylgalactosamine (PA), sugars that are present in the carbohydrate side chains of the mucus glycoproteins (mucins). Ricinus communis, with high affinity for D-galactose and N-acetylgalactosamine, did cause a significant decrease in sperm migration but only within the mucus (not at the sperm-mucus interface); this may have been because of an effect on sperm motility. These sugars are thought to be important for the secondary structure of the glycoproteins and for the cross linking between the mucins that produce the rheologic properties of cervical mucus. However, it appears that interference with the sugars by lectin binding does not significantly alter the ability of spermatozoa to migrate through cervical mucus.