Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The gas-phase dissociation of protein assemblies is becoming crucial for the application of mass spectrometry to structural biology. However certain aspects of the dissociation mechanism remain elusive. Moreover, many protein complexes resist dissociation at the energies accessible with current instrumentation. Here we report new insights into the collision-induced dissociation mechanism of protein assemblies. By holding activation energy constant and varying the charge state of the precursor ion, we show that the total charge of the precursor ion dramatically influences the internal energy required to dissociate monomers from the protein assembly. Furthermore, we have developed a modified quadrupole-time-of-flight instrument capable of accessing activation energies higher than previously possible. Under these conditions, protein assemblies eject subunits with excess internal energy that subsequently fragment into peptides. Together, these data indicate that the non-covalent dissociation is limited by the amount of charge available and not merely the activation energy, and they project the exciting possibility of extracting sequence information directly from intact protein complexes in the gas phase.

Original publication

DOI

10.1021/ac801950u

Type

Journal article

Journal

Anal Chem

Publication Date

01/02/2009

Volume

81

Pages

1270 - 1274

Keywords

Archaeal Proteins, Heat-Shock Proteins, Mass Spectrometry, Peptide Fragments, Proteins, Tandem Mass Spectrometry