Role of Intramolecular Aromatic π-π Interactions in the Self-Assembly of Di-l-Phenylalanine Dipeptide Driven by Intermolecular Interactions: Effect of Alanine Substitution.
Although the role of intermolecular aromatic π-π interactions in the self-assembly of di-l-phenylalanine (l-Phe-l-Phe, FF), a peptide that is known for hierarchical structure, is well established, the influence of intramolecular π-π interactions on the morphology of the self-assembled structure of FF has not been studied. Herein, the role of intramolecular aromatic π-π interactions is investigated for FF and analogous alanine (Ala)-containing dipeptides, namely, l-Phe-l-Ala (FA) and l-Ala-l-Phe (AF). The results reveal that these dipeptides not only form self-assemblies, but also exhibit remarkable differences in structural morphology. The morphological differences between FF and the analogues indicate the importance of intramolecular π-π interactions, and the structural difference between FA and AF demonstrates the crucial role of the nature of intramolecular side-chain interactions (aromatic-aliphatic or aliphatic-aromatic), in addition to intermolecular interactions, in deciding the final morphology of the self-assembled structure. The current results emphasise that intramolecular aromatic π-π interaction may not be essential to induce self-assembly in smaller peptides, and π (aromatic)-alkyl or alkyl-π (aromatic) interactions may be sufficient. This work also illustrates the versatility of aromatic and a combination of aromatic and aliphatic residues in dipeptides in the formation of structurally diverse self-assembled structures.
Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai, 600020, India), Fax: (+91) 44 24911589.|Academy of Scientific and Innovative Research (AcSIR), CSIR-CLRI Campus, Chennai, 600020, India.
Samala Murali Mohan
SM
Reddy
Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai, 600020, India), Fax: (+91) 44 24911589. ganesh@clri.res.in, ganeshclri@gmail.com.|Academy of Scientific and Innovative Research (AcSIR), CSIR-CLRI Campus, Chennai, 600020, India. ganesh@clri.res.in, ganeshclri@gmail.com.
Ganesh
http://orcid.org/0000-0003-1096-4201
G
Shanmugam
D000409:Alanine / Q000737:chemistry*; D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010316:Particle Size; D010666:Phenylpropionates / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties
D004151:Dipeptides; D010666:Phenylpropionates; D000409:Alanine
noncovalent interactions; peptides; pi interactions; self-assembly; solvent casting