Detecting aspartate isomerization and backbone cleavage after aspartate in intact proteins by NMR spectroscopy.

ABSTRACT: The monitoring of non-enzymatic post-translational modifications (PTMs) in therapeutic proteins is important to ensure drug safety and efficacy. Together with methionine and asparagine, aspartic acid (Asp) is very sensitive to spontaneous alterations. In particular, Asp residues can undergo isomerization and peptide-bond hydrolysis, especially when embedded in sequence motifs that are prone to succinimide formation or when followed by proline (Pro). As Asp and isoAsp have the same mass, and the Asp-Pro peptide-bond cleavage may lead to an unspecific mass difference of + 18 Da under native conditions or in the case of disulfide-bridged cleavage products, it is challenging to directly detect and characterize such modifications by mass spectrometry (MS). Here we propose a 2D NMR-based approac

SUBMITTER: Hinterholzer A 

PROVIDER: S-EPMC7897204 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature