Use
glycoprotein: A carbohydratelinked covalently to a protein.Formed in the Golgi apparatus in theprocess of glycosylation, glycoproteinsare important components ofcell membranes. They are also constituentsof body fluids, such asmucus, that are involved in lubrication.Many of the hormone receptorson the surfaces of cells have beenidentified as glycoproteins. Glycoproteinsproduced by viruses attachthemselves to the surface of the hostcell, where they act as markers forthe receptors of leucocytes. Viral glycoproteinscan also act as target moleculesand help viruses to detectcertain types of host cell; for example,a glycoprotein on the surface ofHIV (the AIDS virus) enables the virusto find and infect white blood cells.