The effects of protein-ligand interactions on protein stability are typically monitored by a number of established solution-phase assays. Few translate readily to membrane proteins. We have developed an ion-mobility mass spectrometry approach, which discerns ligand binding to both soluble and membrane proteins directly via both changes in mass and ion mobility, and assesses the effects of these...

Collision induced dissociation (CID) combined with matrix assisted laser desorption ionization-ion mobility-mass spectrometry (MALDI-IM-MS) is described. In this approach, peptide ions are separated on the basis of mobility in a 15 cm drift cell. Following mobility separation, the ions exit the drift cell and enter a 5 cm vacuum interface with a high field region (up to 1000 V/cm) to undergo co...

A series of isobaric disaccharide-alditols, four derived from O-linked glycoproteins, and select trisaccharides were rapidly resolved using tandem high resolution atmospheric pressure ion-mobility time-of-flight mass spectrometry. Electrospray ionization was used to create the gas-phase sodium adducts of each carbohydrate. Using this technique it was possible to separate up to three isobaric di...

An ion mobility-mass spectrometer (IM-MS) interface is described that can be employed to perform collisional activation and/or collision-induced dissociation (CID) with good transmission of mobility separated ions to the MS analyzer. The IM-MS interface consists of a stacked-ring ion guide design, where the field strength and pressure ratio can be operated such that structural rearrangement rea...

Miniaturized ion mobility spectrometers present several advantages as portable chemical detection tools. They are fast, simple and inexpensive. However, they still suffer from low resolving power and hard implementation of ion gates in micro scale designs. Even in examples where they are successfully combined, ion gates cause dispersion, compression, and depletion effects that result in ion pac...