Fig. 6
Reannotation of GXII NISTmAb cathepsin-induced degradation products by accurate assignment of MS identifications (A) CZE-MS identification of 47.6 kDa Fab' fragment due to heavy chain HT cleavage with Cathepsin L incubated at pH 7. (B) CZE-MS identification of 100.5 kDa (H2L2-SS Clip) degradation product due to light chain SS cleavage formed by Cathepsin D incubated at pH 5. Inset shows Fc glycans (C) CZE-MS mass spectrum and corresponding deconvolution spectrum of 18.3 kDa and 18.5 kDa fragment masses formed by cathepsin D incubation at pH 5. (D) Migration time error versus degradation products obtained from the spectral library. Note: migration time errors are shown for GXII peaks 1, 2, 4, 5, 8 and 10. The identity of the library species is assigned to the peak in electropherogram when migration time error is minimized. (E) Reassignment of peaks 2, 4 and 5 in GXII electropherogram with accurate identities. Peaks 1, 8 and 10 are validated to the initial assignments in Fig. 4C.
