Structural characterization of 150 kDa intact antibodies with electron transfer dissociation Orbitrap mass spectrometry

摘要

ETD on Orbitrap FTMS produced 162 identified unique backbone cleavages sites on approx150 kDa intact protein (IgG) on the LC timescale. Sequence coverage obtained by ETD is generally higher than the one obtained by slow-heating activation methods and, importantly, provides valuable information on the variable domains. ETD fragmentation patterns of IgGs derived from different organisms (i. e., with significant differences in sequence-structure) show relevant differences in the number and abundances of product ions, especially in the 200-1200 m/z region. Further improvement in S/N is required for identification of PTMs and increased sequence coverage.