Riboflavin binding protein (RBP) transports riboflavin through the bloodstream of the laying hen into the eggs, where the vitamin is essential for embryonic growth and development. RBP consists of a single polypeptide chain containing 9 disulfide bonds. It is a glycoprotein containing ~14% carbohydrate, with sugar moieties including galactose, mannose and glucosamine, and is phosphorylated.
