Protein , riboflavin binding of hen eggs and the soluble protein of the transport function , and also relatively simple flavoprotein , is extensively studied in terms of molecular structure of the physical-chemical mechanism of protein and protein-ligand interactions . This paper presents the progress of this research over the past several years , starting with the determination of the primary structure of the protein. It exhibits a high degree of homology with the folic acid -binding proteins , and the macromolecule has a unique tertiary structure of the two domains : a highly strained disulfide bonds and the ligand binding domain separate phosphorylated motif responsible for the transport of the protein into the oocyte . Riboflavin molecule binds to a hydrophobic pocket of the macromolecule ; izoalloksazyny arrangement is encased on both sides by tryptophan and tyrosine -156 -75 , and the side-chain anchored ribitol from a number of hydrogen bonds . In recent studies definitively established the structure of the sugar component and presents the general characteristics of the process of folding the native structure of the protein.