Analytical characterization of the conformational transitions of polynucleotides by means of different molecular spectroscopies and multivariate curve resolution

A general procedure for the study of conformational transitions of polynucl eotides is described. The equilibria between different conformations induce d by salt, ethidium bromide, and temperature of poly(dG-dC).poly(dG-dC) and induced by salt and temperature of poly(A).poly(U) are investigated using molecular absorption, circular dichroism, and fluorescence spectroscopies. Spectral data obtained from experiments are analyzed by means of a factor a nalysis method, namely, multivariate curve resolution, which allows possibl e intermediate states to be detected and the pure spectra and the concentra tion profiles of all species present in the system to be estimated. This wo rk shows the application of this procedure for the analysis of data matrice s obtained in individual experiments but also for the analysis of several d ata matrices simultaneously. (C) 2001 Academic Press.