Monday, January 25, 2016
UV-photodissocation on a Q Exactive may boost PTM identification!
I'm still wrapping my head around this brand new paper from Kyle Fort et al., (appears available to anyone registered with ACS).
What is it? A Q Exactive with an altered HCD cell. The HCD cell has lasers(?!?!?) in it. The lasers can rapidly cause UV-photodissocation in the HCD cell. This doesn't appear to affect the ability of the HCD cell to do HCD.
What does it do? Well, it appears that it massively decreases the amount of neutral losses (?!?!?) in fragmentation leading to richer and more complete MS/MS spectra of peptides with post-translational modifications. If you're thinking "wait, isn't that what ETD does..." Me too! Sure, it doesn't work anything along the same lines, but it looks like there is potential here to get data better coverage of PTMs (like with ETD) but maybe a whole lot faster(??)
This is the second time recently I've seen a paper describe a laser equipped HCD cell. It still seems weird, but if you are going to take my favorite mass spectrometer and say that now you've increased its capabilities, I'm gonna get really really excited about it.
Is this just a one-off weird thing that none of us will ever be able to do? Maybe. But two of the authors of this paper are kind of familiar to me....Heck and Makarov. Seems to me that the last time I got super excited about a paper with these two names on it, we later ended up with a super cheap and amazingly underutilized Orbitrap that could do intact proteins and protein complexes better than any instrument in the world. So I'm gonna keep my fingers crossed!