Retinol binding protein (RBP) from PDB file 1RBP

Retinol binding protein is a serum (in blood) transporter that binds retinol (vitamin A) for transport through the body. Retinol is a hydrophobic (water-insoluble) molecule, thus requiring a protein transporter. The protein has hydrophobic amino acid sidechains that bind retinol in its interior barrel while the outside surface of the protein is covered with hydrophilic and charged amino acid sidechains making it soluble. In this model, key hydrophobic residues were displayed inside the barrel. T