Author Archives: Konijnenberg A, Yilmaz D, Ingólfsson HI, Dimitrova A, Marrink SJ, Li Z, Vénien-Bryan C, Sobott F, Koçer A

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry.

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry.

Proc Natl Acad Sci U S A. 2014 Nov 17;

Authors: Konijnenberg A, Yilmaz D, Ingólfsson HI, Dimitrova A, Marrink SJ, Li Z, Vénien-Bryan C, Sobott F, Koçer A

Abstract
Mechanosensitive ion channels are sensors probing membrane tension in all species; despite their importance and vital role in many cell functions, their gating mechanism remains to be elucidated. Here, we determined the conditions for releasing intact mechanosensitive channel of large conductance (MscL) proteins from their detergents in the gas phase using native ion mobility-mass spectrometry (IM-MS). By using IM-MS, we could detect the native mass of MscL from Escherichia coli, determine various global structural changes during its gating by measuring the rotationally averaged collision cross-sections, and show that it can function in the absence of a lipid bilayer. We could detect global conformational changes during MscL gating as small as 3%. Our findings will allow studying native structure of many other membrane proteins.

PMID: 25404294 [PubMed – as supplied by publisher]

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