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

Leclercq, Loïc

In 1996, Bekos et al. investigated the role of the L-tyrosine (Tyr) residue in the binding of pentapeptides to α-and β-CD [88] . The two peptides used in this study were: Tyr-Ile-Gly-Ser-Arg (YIGSR) and Tyr-Gly-Gly-Phe-Leu (YGGFL). The former interacts specifically with the integrin receptors on specific neuronal cells whereas the latter is known to bind to brain receptor sites. From steady-state fluorescence spectroscopy, the estimated constants of free Tyr increased in the order α-CD < β-CD. As in the previous study, the stability constants of pentapeptides containing Tyr with β-CD were higher than that of Tyr itself (48, 224 , and 123 M -1 for free Try, YIGSR, and YGGFL, respectively). Therefore, the pentapeptide conformation affects the stability of the pentapeptide/β-CD inclusion complex. In contrast, the pentapeptide/α-CD inclusion complex was not affected by the oligopeptide conformation (27, 20 , and 20 M −1 for free Try, YIGSR, and YGGFL, respectively).