Protecting Group-Directed Diversity in the Morphology of Self-Assembled Ant-Aib Dipeptides: Garland-Like Architecture and Nanovesicle Formation

Abstract

The morphology and molecular organization of a set of different N-terminal protecting groups containing dipeptides were investigated. The dipeptides consisted of two rigid noncanonical amino acids, Ant and Aib (X-Ant-Aib-OMe; Ant: anthranilic acid and 2-aminobenzoic acid, Aib: 2-aminoisobutyric acid). The change of the N-terminal protecting groups (X = Boc (peptide 1), N α-fluorenylmethoxycarbonyl (Fmoc) (peptide 2), o-NBS (peptide 3), and p-NBS (peptide 4); NBS = nitrobenzyl sulfonyl group) displayed a characteristic morphological variety. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) experiments suggested that while t-butyloxycarbonyl (Boc) and p-NBS containing peptides exhibited distinct rod-like fiber structures, Fmoc and o-NBS containing peptides displayed remarkable vesicular structures. FE-SEM and thermogravimetric analysis (TGA) suggested that peptide nanostructures demonstrated excellent thermal stability in dry conditions. Interestingly, peptides 2 and 4 exhibited a type-III N2 gas adsorption isotherm. Fluorescence microscopy analysis revealed that nanovesicles formed by peptides 2 and 3 have drug encapsulation properties exemplified by curcumin, rhodamine B, and carboxyfluorescein. These results will help in designing peptide-based nanomaterials for diverse applications.

Influence of Chirality on the Self-Assembly of Dipeptides and Sensing of Fe3+

“…1−3 Supramolecular self-assembly based on small peptides creates significant interest because of chemical diversity, cost-effectiveness, and convenient modulations compared to other molecules. 4 Peptide self-assembly offers various nanostructures 5−9 including nanowires, 10 nanofibrils, 11,12 nanoribbons, 13 nanospheres, 14 nanotapes, 15 nanobelts, 16 nanovesicle, 17 and nanotubes 18 depending on the internal and external forces. Peptide nanostructures typically exhibit good biocompatibility, low toxicity, low immunogenicity, biodegradability, and target specificity.…”

“…Molecular self-assembly is a procedure for creating ensembles of nanostructures, where molecules autonomously assemble through diverse noncovalent interactions (van der Waals, electrostatic, H-bonding, π–π stacking, and hydrophobic interactions). − Supramolecular self-assembly based on small peptides creates significant interest because of chemical diversity, cost-effectiveness, and convenient modulations compared to other molecules . Peptide self-assembly offers various nanostructures − including nanowires, nanofibrils, , nanoribbons, nanospheres, nanotapes, nanobelts, nanovesicle, and nanotubes depending on the internal and external forces. Peptide nanostructures typically exhibit good biocompatibility, low toxicity, low immunogenicity, biodegradability, and target specificity. − Consequently, they find widespread applications in drug delivery, tissue engineering, biomedical, cell culture, nanoelectronics, and sensors .…”

Versatility in self-assembly and morphology of non-coded anthranilic acid and phenylglycine based dipeptide stereoisomers

“…11 We recently described the protecting group-directed diversity of supramolecular structures and morphologies of Ant-Aib di-peptides. 12 Moreover, incorporation of Ant in hIAPP 8–37 increases anti-amyloidogenic properties. 13 Kumar et al reported anthranilamide-based short peptides forming self-organized hydrogels, which act as antibacterial agents.…”