Towards the understanding of halogenation in peptide hydrogels: a quantum chemical approach. Issue 14 (25th June 2021)

• Record Type: Journal Article
• Authors: Bettens, Tom; Lacanau, Valentin; Van Lommel, Ruben; De Maeseneer, Tess; Vandeplassche, Wouter; Bertouille, Jolien; Brancart, Joost; Barlow, Thomas M. A.; Woller, Tatiana; Van den Brande, Niko; Moldenaers, Paula; De Proft, Frank; Madder, Annemieke; Hoogenboom, Richard; Martin, Charlotte; Ballet, Steven; Alonso, Mercedes
• Is Part Of: Materials advances. Volume 2:Issue 14(2021)
• Page Start: 4792
• Page End: 4803
• Publication Date: 2021-06-25
• Subjects: 620.11
• DOI: 10.1039/d1ma00455g
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : Halogenation matters! The stacking between phenylalanine side chains can be tuned by halogen atoms attached to the aromatic ring. Herein, computational data are successfully applied in the design of peptide hydrogels with increased stiffness. Abstract : Non-covalent interactions involving aromatic rings play a central role in many areas of modern chemistry. In medicinal and bioorganic chemistry, the intermolecular interactions between the aromatic side chains of amino acids, such as phenylalanine and tyrosine, are of great interest. To enhance the affinity between such aromatic side chains, halogenation is a promising modification strategy. In the current work, the nature and strength of halogenated π–π stacked phenylalanine (Phe) dimers have been investigated using density functional theory, energy decomposition analyses and the non-covalent interaction (NCI) method. Our analysis shows that increasing the degree of halogenation enhances the strength of the stacking interactions and, moreover, the heavier halides (Cl, Br and I) lead to stronger interactions compared to the lighter F. This effect was traced back to local secondary interactions of the halide with the aliphatic C–H bonds of the phenylalanine side chain. Based on the computational findings, a set of peptide hydrogelators was synthesized, and the resulting hydrogel properties were further investigated via dynamic rheometry. Experimental observations can be correlated to the trends found in the theoretical analysis, suggesting that local interactions indeed play a noticeable role in enhancing peptide-based hydrogel strength.