Wednesday, July 27, 2016
Another awesome UVPD phosphoproteomics study!
I swear I'm almost going to stop reading papers where people have "hacked" their Orbitraps and added UV photo-dissociation to them. Maybe this is the last one.
This is (one of?) Jenny Broadbelt's systems it seemed like everybody at ASMS was talking about and described in this new paper by Michelle Robinson et al.,.
In this case they modify an Orbitrap Fusion (yikes!) and add UVPD to the HCD cell. They IMAC enrich phosphopeptides from cancer cells and alternate HCD/UVPD and investigate both positive and negative modes.
The HCD still wins in terms of most identified peptides (15k resolution MS/MS scans), but the UVPD peptides are highly complimentary to the ones identified via UVPD. The negative stuff looks the least efficient in terms of ID's per time, but identifies even more complimentary phospho peptides identified by the other techniques.
They use PD 1.3 and Sequest for the data processing. Part of me seriously wonders if they could do a lot better with the modified OMSSA Coon Lab has been using, or with the modified Byonic that was described a few weeks ago.
In the end, though, we're looking at another description of UVPD that shows it has enormous power. Unfortunately, no one is discussing commercial release. Looks like some of us here in MD need to buy a laser and a voltmeter and get rewiring. I've got a spare weekend coming up... (P.S., I'm mostly joking)