Gas phase thermal denaturation of an oligonucleotide duplex and its complexes with minor groove binders

Electrospray ionization with in-source collisionally induced dissociation h as been used to probe the gas phase stability of an oligonucleotide duplex and its complexes with some minor groove binding drugs. On the basis of the arguments developed in detail by Drahos et al, (J, Mass Spectrom. 1999; 34 :1373), this type of experiment can also be described as 'thermal denaturat ion in the gas phase'. We found that the gas phase denaturation curves were very similar to the solution phase denaturation curves determined by the t raditional UV spectrophotometric method and, by analogy with the melting te mperature T-m which characterizes the stability in solution, we define a me lting voltage V-m to characterize the stability in the gas phase. A compari son of the T-m and V-m relative values suggests that the structure of the c omplexes is conserved during the electrospray process which transfers the i ons from the solution to the gas phase. Copyright (C) 2000 John Wiley & Son s, Ltd.