ION-ION PROTON-TRANSFER REACTIONS OF MULTIPLY-CHARGED OLIGONUCLEOTIDECATIONS

Multiply-charged cations derived from the positive ion electrospray of the oligonucleotide 5'-d(CT-TAGCGCTAAG)-3' were subjected to reaction s with the (M-CF3)(-) and (M-F)(-) anions derived from perfluoro-1,3-d imethylcyclohexane in a quadrupole ion trap. Both single strand ions a nd double strand ions formed from the self-complementary oligonucleoti de were studied. In analogy with the reactions of multiply-protonated proteins with the same anions, no adduct formation was observed and th e data were consistent with exclusive proton transfer. No evidence for fragmentation was observed for either the single strand ions or the d ouble strand ions, although a small degree of fragmentation of the lat ter species could not be precluded based on these results alone. The s imple and well-defined chemistry associated with the ion-ion reactions of oligonucleotide cations with anions derived from PDCH is desirable for the charge-state manipulation of moderately-sized oligomers (up t o roughly 100 residues) because PDCH anions possess a number of desira ble characteristics for the production and storage of ion/ion reaction products with mass-to-charge ratios in the tens of thousands. (C) 199 7 Elsevier Science B.V.