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Counter-ion-specific helix formation of poly(γ-methyl L-glutamate) derivatives containing sulfonate group in aqueous alcohols

✍ Scribed by Akihiro Ando; Mitsuru Satoh


Publisher
John Wiley and Sons
Year
2001
Tongue
English
Weight
142 KB
Volume
50
Category
Article
ISSN
0959-8103

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✦ Synopsis


Abstract

Charged polypeptides containing sulfonate groups were prepared by transesterification of poly(γ‐methyl L‐glutamate) with isethionic acid. The coil–helix transition of the sulfonated polypeptides was investigated in aqueous alcohols. Marked counter‐ion specificity was observed for helix formation: Li^+^ < Na^+^ < Cs^+^ ≦ Rb^+^ ≦ K^+^; this was different to that for poly(L‐glutamate) (PLG): Cs^+^ ≪ K^+^ < Li^+^ < Na^+^. Specific helix stabilization by counter‐ion mixing, which has been found for the PLG system, was not observed for the sulfonated polypeptides. The counter‐ion‐ and solvent‐specific helix formation is discussed and compared with that in PLG.

© 2001 Society of Chemical Industry