Amphiphilic peptides bearing an alternating binary pattern of hydrophilic and hydrophobic repeating units were synthesized via polymerization exploiting Ugi’s four-component condensation reaction (Ugi’s 4CC) as the elemental polymerization reaction. We performed turbidity measurements on the aqueous polymer solutions at various temperatures. The results showed that the structural effects of the alternating peptides had the following impacts on thermoresponsiveness: (i) alternating peptides consisting of repeating hydrophilic and hydrophobic units tended to adopt upper critical solution temperature (UCST) behavior; and (ii) when the hydrophobes in the polymer were large enough for the intrachain hydrophobic interactions, the polymer displayed lower critical solution temperature (LCST) behavior. We also prepared thermoresponsive hydrogels comprising alternating peptide skeletons as the cross-linking points. Alternating peptides with LCST behavior may be useful for creating peptide-based smart materials in the future.
- Namiki Komuro
- Noriyuki Nakajima
- Yasuhito Koyama
