Mass spectrometry and tandem MS are important tools in structural biology owing to the high sensitivity, speed, and information content obtainable with these methods.  Tandem MS is commonly used to identify proteins and characterize posttranslational modifications.  Highly charged ions formed with electrospray ionization are advantageous for these measurements because they dissociate more readily to produce structurally useful information, and are more easily detected in orbitrap or Fourier-transform ion cyclotron resonance instruments that use charge-sensitive detection.  Solutions in which proteins are denatured are commonly used to obtain high charge states, but information about protein activity, conformation, protein-protein binding, complex assembly and stoichiometry is lost.  Various strategies to significantly increase the charging on biomolecules and complexes formed from solutions in which these molecules have native structure and activity will be presented, including the use of supercharging reagents as well as new electrothermal supercharging method.  With these methods, charge states greater than the number of basic sites in a protein can be produced from solutions in which the proteins have native structures and reactivities.  These methods largely eliminate the need to use denaturing solutions for mass spectral measurements of proteins.  These methods are also advantageous for the analysis of large molecules with molecular weights in excess of 1 MDa using a newly developed single particle analyzer for mass and mobility (SPAMM) instrument that uses charge detection.  This instrument is capable of measuring the masses of individual ions and can be used to provide molecular weight information from samples that are too high in molecular weight or too heterogeneous to be analyzed with conventional mass spectrometers.  The performance of the newest implementation of this instrument and its use to characterize complex samples will be presented.  Experiments in which two or more solutions are rapidly mixed are widely used study a wide range of physical phenomenon.  A new method to rapidly mix two solutions that combines the advantages of the fastest mixing times with the analytical advantages of mass spectrometry analysis will be presented.

Supercharging, fast mixing, and charge detection in mass spectrometry

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.