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

Leclercq, Loïc

From the findings described above, it can be presumed that the effect of CD is directly linked to its ability to complex Trp and the behavior of Me-α-CD can be related to its cavity size. The binding constants are always weaker with modified α-CD than with functionalized β-CD (see discussion above). In 2009, a 1 H NMR spectroscopic study revealed that the 1 H NMR signals corresponding to Trp residues were shifted upon the addition of G1-β-CD due to encapsulation of the tryptophan residues in the G1-β-CD cavity [92] . In addition, the 1 H NMR signals for cysteine 64 and isoleucine 98 were also influenced to a considerable extent with the addition of G1-β-CD. This allows the conclusion that these hydrophobic amino acid residues are also included by this CD. These results are highly compatible with the very important thermal stability reduction observed in the presence of G1-β-CD. Therefore, the interaction of CDs with proteins is very complicated due to the presence of many binding sites.