Peptides bistability in ion mobility might explain a lot of things!

 

Okay - somewhere on this blog a few years ago is a post that is called something like "what the hell is ion mobility"? And I'm continually learning - or trying to - and might have just given 3 talks doing proteomics with ion mobility devices. I might still only partially know what it is and I certainly couldn't build you one.

However, I'm occasionally surprised by measured versus predicted ion mobilities. And I'm often troubled by how ion mobility clouds are altered by things like isobaric tags. And for the former problem....this new preprint is really really interesting.

Why couldn't a peptide have multiple ways to be pulled through a gas gradient? I mean...it seems like you could probably flip 50% of your peptide population A one direction and 50% the other and they'd have different "shapes" - and it's not like the peptide bond is a crystal lattice. (Lettuce? Now I'm hungry). It seems like a curiosity until you see how much their IMS predictions improve when the model allows the entry of 2 stable IMS readings for each peptide....