Pendular proteins in gases and new avenues for characterization of macromolecules by ion mobility spectrometry.

ABSTRACT: Polar molecules align in electric fields when the dipole energy (proportional to field intensity E x dipole moment p) exceeds the thermal rotational energy. Small molecules have low p and align only at inordinately high E or upon extreme cooling. Many biomacromolecules and ions are strong permanent dipoles that align at E achievable in gases and room temperature. The collision cross-sections of aligned ions with gas molecules generally differ from orientationally averaged quantities, affecting ion mobilities measured in ion mobility spectrometry (IMS). Field asymmetric waveform IMS (FAIMS) separates ions by the difference between mobilities at high and low E and hence can resolve and identify macroion conformers based on the mobility difference between pendular and free rotor states. The e

SUBMITTER: Shvartsburg AA 

PROVIDER: S-EPMC2672539 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature