0000000001119394
AUTHOR
D. Bongiorno
Degrees of freedom effect on fragmentation in tandem mass spectrometry of singly charged supramolecular aggregates of sodium sulfonates
The characteristic collision energy (CCE) to obtain 50% fragmentation of positively and negatively single charged noncovalent clusters has been measured. CCE was found to increase linearly with the degrees of freedom (DoF) of the precursor ion, analogously to that observed for synthetic polymers. This suggests that fragmentation behavior (e.g. energy randomization) in covalent molecules and clusters are similar. Analysis of the slope of CCE with molecular size (DoF) indicates that activation energy of fragmentation of these clusters (loss of a monomer unit) is similar to that of the lowest energy fragmentation of protonated leucine-enkephalin. Positively and negatively charged aggregates be…
Collision induced fragmentations of multiply charged sodium bis(2-ethylhexyl)-sulfosuccinate aggregates in gas phase: neutral loss versus charge separation
Abstract Stability and fragmentation patterns of multicharged aggregates of sodium bis(2-ethylhexyl)-sulfosuccinate (NaAOT) in gas phase have been investigated by ion mobility mass spectrometry (IM-MS) and tandem mass spectrometry (MS-MS). Positively doubly charged NaAOT aggregates show at low collision energy a preference for the loss of NaAOT molecules, whereas fragmentation through charge separation process is favored at higher collision energy. By increasing the charge state of the aggregates, the fragmentation through charge separation tends to predominate especially at low aggregation number and only charge separation fragmentation is observed for positively quadruply charged species.…
Interactions of tryptophan and serotonin with biomembrane models: Binding to reversed micellar systems of ionic and non ionic surfactants
The interactions of Tryptophan (TRP) and Serotonin (5-HT), with water-containing sodium bis (2-ethylhexyl) sulfosuccinate (AOT), didodecyldimethylammonium bromide (DDAB) and tetraethylene glycol monododecyl ether (C12E4) reversed micelles have been investigated by UV absorption spectroscopy. Our results suggest that independently of the nature of the surfactant and the amount of the water encapsulated into the micellar core, TRP and 5-HT are solubilized in the micellar phase, preferring to be located in a shallow region constituted by the hydrated surfactant head groups. This is due to the amphiphilic nature of TRP and 5-HT and the biological implications are discussed.