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University of Wollongong

Faculty of Science - Papers (Archive)

Series

2007

Ion

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Direct Imaging Of Lipid-Ion Network Formation Under Physiological Conditions By Frequency Modulation Atomic Force Microscopy, Michael J. Higgins, Suzi P. Jarvis, Takeshi Fukuma Jan 2007

Direct Imaging Of Lipid-Ion Network Formation Under Physiological Conditions By Frequency Modulation Atomic Force Microscopy, Michael J. Higgins, Suzi P. Jarvis, Takeshi Fukuma

Faculty of Science - Papers (Archive)

Various metal cations in physiological solutions interact with lipid headgroups in biological membranes, having an impact on their structure and stability, yet little is known about the molecular-scale dynamics of the lipid-ion interactions. Here we directly investigate the extensive lipid-ion interaction networks and their transient formation between headgroups in a dipalmitoylphosphatidylcholine bilayer under physiological conditions. The spatial distribution of ion occupancy is imaged in real space by frequency modulation atomic force microscopy with sub-Angstrom resolution.


Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon Jan 2007

Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon

Faculty of Science - Papers (Archive)

Changes in protein conformation are thought to alter charge state distributions observed in electrospray ionization mass spectra (ESI-MS) of proteins. In most cases, this has been demonstrated by unfolding proteins through acidification of the solution. This methodology changes the properties of the solvent so that changes in the ESI-MS charge envelopes from conformational changes are difficult to separate from the effects of changing solvent on the ionization process. A novel strategy is presented enabling comparison of ESI mass spectra of a folded and partially unfolded protein of the same amino acid sequence subjected to the same experimental protocols and conditions. …