Rapid, Label-Free Soft Spot Identification (SSID) of Cyclic Peptides
Rapid, Label-Free Soft Spot Identification of Cyclic Peptides
Ashli R. Simone, Jordan Stewart, and Michelle English
The identification of “soft spots” in cyclic peptides is a challenging, time-consuming process that can be greatly enhanced by incorporating high-resolution ion mobility-mass spectrometry (HRIM-MS) into these analytical workflows. HRIM can resolve isomeric ring-opening events from cyclic peptide hydrolysis, greatly simplifying fragmentation spectra for more confident identification of the ring-opening sites. Further, this is done in the absence of labels or other expensive materials using only a guard column and a rapid 1-minute LC method with standard solvents and modifiers, reducing costs and improving throughput.
• Resolve isomeric open-ring forms of cyclic peptides and identify soft spots 30 times faster than traditional tagging LC-MS methods
• Eliminate lengthy sample prep that can take 2 hours to overnight to tag samples
• Simplify soft spot identification with the addition of MAF spectral improvements
• Reduce uncertainty with less than 0.25% RSD for MS1-based identification by CCS