Interactions between cyclodextrins and cellular components: Towards greener medical applications?

Leclercq, Loïc

Proteins are polymers of amino acids covalently linked through peptide bonds. The nature of the proteins is determined primarily by their amino acid sequence, which constitutes their primary structure. Amino acids have very different chemical properties; their arrangement along the polypeptide chain determines their spatial arrangement. This is described locally by their secondary and tertiary structures. The secondary structure describes the arrangement of amino acid residues observed at the atomic scale stabilized mainly by H-bonds (e.g., α-helix, β-sheet and turns). The tertiary structure corresponds to the general shape of the observable protein across the whole molecule. It describes the interactions between the different elements of the secondary structure. Finally, the assembly of several protein subunits to form a functional complex is described by the quaternary structure [54] . As some amino acids have hydrophobic side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, cysteine and methionine), they can be easily included inside the CDs. This complexation leads to modification of the protein. For sake of clarity, only some typical examples are reported in this section.