A Capped Dipeptide Which Simultaneously Exhibits Gelation and Crystallization Behavior.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biochemistry

Background:

• N-capped short peptides are effective gelators but difficult to crystallize due to unidirectional fiber interactions.
• Understanding the molecular basis of peptide self-assembly is crucial for designing novel functional materials.

Purpose of the Study:

• To synthesize and characterize a novel N-capped dipeptide capable of forming both hydrogels and single crystals.
• To investigate the coexistence of hydrogel and crystalline phases at the molecular level.
• To challenge and refine existing models of short peptide gelation.

Main Methods:

• Synthesis of benzimidazole-diphenylalanine (a novel N-capped dipeptide).
• Atomic force microscopy (AFM) to observe phase coexistence.
• Powder X-ray diffraction (PXRD) to analyze hydrogel structure.

Main Results:

• Successful synthesis of the N-capped dipeptide, benzimidazole-diphenylalanine.
• Demonstrated coexistence of hydrogel and single crystal phases using AFM.
• PXRD analysis suggests a parallel β-sheet arrangement in the hydrogel, consistent with the crystal structure.

Conclusions:

• The synthesized dipeptide forms both hydrogels and crystals, a rare phenomenon.
• The findings challenge current models of short peptide gelation.
• This work provides a foundation for the rational design of new peptide-based gelators and self-assembling materials.