Accueil > Publications > Recherche par années > Années 1990 > 1994

Baumruk, V ; Huo, DF ; Dukor, RK ; Keiderling, TA ; Lelièvre, D ; Brack, A

Conformational study of sequential lys-based and leu-based polymers and oligomers using vibrational and electronic CD-spectra

Biopolymers 34 (8) 1115-1121

par Administrateur - publié le

Abstract :

Vibrational CD (VCD) and electronic CD (ECD) spectra of some sequential Lys and Leu based oligo- and polypeptides were studied as a function of added salt and (for ECD) as a function of concentration in aqueous solution. For these samples, the VCD spectra can only be measured at relatively high concentrations under which the well-known salt-induced transition to a ß-sheet form can be observed for the KL based species, but only the end-state a-helical conformation is obvious for the LKKL based samples. ECD concentration dependence demonstrates that, at high concentration with no added or with added salt, LKKL based oligomers and polymers give a-helical spectra. These data provide evidence of aggregation induced secondary structure formation in an exceptionally simple peptide system. Similarly, the KL based oligomers and polymers give ß-sheet like spectra at high concentration or at high salt.