Electrospray ionization (ESI) mass spectrometry (MS) is used to study the non-covalent interactions of short 12-mer oligonucleotides under native conditions. A home-built, temperature-controlled ESI source is employed to elevate the spray temperature above the melting temperature (T-m) of the DNA duplexes, enabling the study of DNA interactions in the liquid phase rather than gas phase. Ion mobility spectrometry (IMS)-MS is used to investigate the 3-dimensional structure of the hybridized oligonucleotides and to track conformational changes in the oligonucleotide duplexes during temperature-induced melting in solution. Results show two additional drift times at T > 35 degrees C, indicating 2-fold (partial) unfolding dynamics for the DNA duplex with stable intermediates. (C) 2017 Elsevier B.V. All rights reserved.

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Elsevier B.V.
The Netherlands Organisation for Scientific Research (NWO)
Int. J. Mass Spectrom.

Hommersom, B., Siegel, T. P., & Heeren, R. (2017). Ion mobility spectrometry reveals intermediate states in temperature-resolved DNA unfolding. Int. J. Mass Spectrom., 419, 52–55. doi:10.1016/j.ijms.2017.03.008