Study on the reaction of triple helix poly(A:2I) with Cu2+

The effect of Cu2+ on the triple-stranded helical structure of poly(A:2I) was studied by means of circular dichroism spectral method with the help of ultraviolet spectral and ethidium bromide fluorescence probe methods. It was found that Cu2+ destabilizes the structure of the triple helix poly(A:SI) and induces its structural transformations, meanwhile, the transformations can be partially reversed by a higher NaCl concentration. The structural transformations may be expressed by the following scheme: poly(A:2I) --> poly(A:I) + poly(I) --> poly(A) + 2poly(I)