Simultaneous Occurrence of Nanospheres and Nanofibers Self-Assembled from Achiral Tripeptides.

The achiral tripeptide Boc-Aib-MABA-Aib-OMe has the ability to co-exist as nanospheres and as a network of nanofibers in methanol. Furthermore, AFM and TEM images show the presence of bulges in the network of nanofibers. Interestingly, the formation of nanofibers is seen to emerge from the outer boundary of the spherical structures. Some of the nanofibers curl up at the tip and later result in the formation of hollow nanospheres with thick boundaries. The presence of β-turn-like structures with hydrogen bonding is observed using FT-IR studies. The presence of hydrogen bonding is also demonstrated by using NMR studies.