Comprehensive Characterization Of An Engineered Cas9 Protein And Its Post Translational Modifications (PTMs) By LC-MS/MS

By Zhichang Yang, Sahana Mollah, Chao-Xuan Zhang, Alicia Powers and Yan Lu, SCIEX, USA ; St. Jude Children’s Research Hospital, USA

This content is brought to you by SCIEX, a Danaher Operating Company.

Explore this comprehensive characterization of an engineered Cas9 protein using Zeno trap-boosted electron-activated dissociation (EAD). Here an LC-MS/MS approach was applied to achieve >95% sequence coverage and confident identification of PTMs.

EAD led to 95% sequence coverage of the Cas9 protein, excellent fragmentation of long peptides, differentiation between deamidation of isoAsp and Asp residues, and superior PTM confirmation by preserving side chain information. In addition, the highly sensitive collision-induced dissociation (CID) enabled the confident identification of peptides with low-abundant mutations.