Collision induced unfolding coupled with gas-phase hydrogen/deuterium exchange give evidence for highly zwitterionic proteins in the gas phase

• The net charge of a natively folded electrosprayed protein can be accurately predicted from the protein size. How charges are distributed on a protein – the charge configuration – is still a challenge however, both to determine experimentally and to predict from theory and computations, hampering both modelling and interpretation of native mass spectrometry experiments. Here, a combination of molecular dynamics simulations and experiments, including a novel conjunction of collision induced unfolding and gas-phase hydrogen/deuterium exchange, were used on a set of engineered proteins differing in their surface chemistry to general principles underpinning the charge configurations. Testing three charging models against simulations and experiments, only the highly zwitterionic model passed falsification efforts. Our results are consistent with the notion of the proteins being partially kinetically trapped in a charge configuration inherited from solution.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

mass spectrometry

molecular dynamics

electrospray ionisation

protein

proton transfer

gas-phase hydrogen/deuterium exchange

collision induced unfolding

Biokemi

Biochemistry

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)