Primary amino acid sequence analysis of the peptide fragments of HS628 and originator tocilizumab was obtained by using reduced peptide mapping
followed by RP-UPLC-MS sequencing, which resulted in 100% sequence coverage for the heavy chain and light chain of two products.
Tertiary structure-selective characterization of protein dithiol groups by phenylarsine oxide modification and mass spectrometric peptide mapping
. Methods in Enzymology 251:430-435.
UNIFI, a solution initially developed for intact protein mass analysis, peptide mapping
and supporting general bioseparations, has been extended to support a mix of quadrupole time-of-flight (Q-Tof) MS and optical detection instruments within a networked lab workgroup.
During the 1960s and 1970s, 2-dimensional peptide mapping
on paper and ion exchange mapping on Dowex resins led to the identification of many new variants until these techniques were eventually superseded by reversed-phase HPLC in the 1980s.
However, not all proteins can be correctly identified through peptide mapping
, in which case fragment analysis by tandem mass spectrometers is necessary.
Analogous to LC peptide mapping
, the molecule is initially digested into smaller parts using enzymic or chemical means and then the mixture of peptides produced is analysed using ES or MALDI MS.
We used tryptic peptide mapping
to confirm this supposition and to obtain a more accurate measurement of the decrease in mass.
of proteins in cerebrospinal fluid utilizing a rapid preparative two-dimensional electrophoretic procedure and matrix-assisted laser desorption/ionization mass spectrometry.
Because of this, the N-terminal acetylation that was postulated based on the observed relative molecular mass of the intact protein could not be verified through peptide mapping
. The 3 enzymatic digestion protocols produced very high sequence coverage for cTnI, including several peptides verifying acetylation of the N-terminal region.