Binding of divalent cations with poly () and their effects on the polypeptide conformation

Secondary structures of synthetic polypeptide polymers

Synthetic peptide-based polymers can fold into different secondary structures in the same way as do proteins. This review article presents how tuning the polypeptide secondary structure could be a key step to modulate various properties in advanced polymeric materials (size, rigidity, self-assembly,etc.).

Cd2+ coordination: an efficient structuring switch for polypeptide polymers

Stimuli-responsive polypeptides have practical applications in devices and therapeutic delivery. Here we report that coordination to Cd²⁺ metal species can be used as a robust stimulus to control both, α-helix and β-sheet secondary structuring of polypeptide polymers.

Smart metallopoly(l-glutamic acid) polymers: reversible helix-to-coil transition at neutral pH

Coordination to Zn species can be reversibly used to control the helix-to-coil transition of synthetic poly(l-glutamic acid) polymers at a neutral pH of 7.

Helix formation of poly (L-glutamic acid) in the presence of alkaline earth metal cations in aqueous alcohol solutions

Effects of divalent counterions (Mg2+, Ca2+, Sr2+, Ba2+) on the helix formation of poly(L-glutamic acid) are investigated in aqueous alcohol (MeOH, EtOH, 2PrOH, tBuOH) solutions. To observe helix formation inherent to the divalent counterions, the chlorides were added to a poly(L-glutamate) having an inert monovalent counterion, tetrabutylammonium cation. Marked counterion- and alcohol-specificities were observed for the dependence of helix content, theta, on the alcohol content. The theta values for most Mg2+ and Ca2+ systems decreased with increasing alcohol content in a higher alcohol region, while those for Sr2+ and Ba2+ systems were almost constant. A specific helix stabilization was observed for mixed divalent counterion systems. These results are self-consistently interpreted by taking into account contact ion-pair formation between the counterions and the polymer charges on the coil conformation.