The behaviour of high molecular weight [poly(dA–dT)·poly(dA–dT)] (polyAT) [(0.9–1.9)×106 Da] in the quaternary water-in-oil microemulsion CTAB–n-pentanol–n-hexane–water has been studied as a function of temperature and NaCl concentration by means of UV and circular dichroism (CD) spectroscopy. Solubilization in the microemulsion stabilises the polymer double helix and no helix-to-coil thermal transition has been observed. At increasing NaCl concentration, the CD spectrum of polyAT exhibits dramatic changes and for salt concentrations [gt-or-equal]7.5×10−1 M the spectral pattern suggests the formation of aggregates of the ψ(−) type. Condensation is induced by the peculiar characteristics of the aqueous core of the microemulsion. The condensates seem to destabilise the microemulsive system and, with time, separate from it.
A spectroscopic study of poly(dA-dT).poly(dA-dT) in microemulsions / Airoldi, M.; Boicelli, C. A.; Gennaro, G.; Giomini, Marcello; Giuliani, A. M.; Giustini, Mauro. - In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS. - ISSN 1463-9076. - STAMPA. - 2:20(2000), pp. 4636-4641. [10.1039/B003745L]
A spectroscopic study of poly(dA-dT).poly(dA-dT) in microemulsions.
GIOMINI, Marcello;GIUSTINI, Mauro
2000
Abstract
The behaviour of high molecular weight [poly(dA–dT)·poly(dA–dT)] (polyAT) [(0.9–1.9)×106 Da] in the quaternary water-in-oil microemulsion CTAB–n-pentanol–n-hexane–water has been studied as a function of temperature and NaCl concentration by means of UV and circular dichroism (CD) spectroscopy. Solubilization in the microemulsion stabilises the polymer double helix and no helix-to-coil thermal transition has been observed. At increasing NaCl concentration, the CD spectrum of polyAT exhibits dramatic changes and for salt concentrations [gt-or-equal]7.5×10−1 M the spectral pattern suggests the formation of aggregates of the ψ(−) type. Condensation is induced by the peculiar characteristics of the aqueous core of the microemulsion. The condensates seem to destabilise the microemulsive system and, with time, separate from it.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
