Characterization of Therapeutic Antibodies with a Protease that Cleaves after Proline & Alanine

Part # PS416

Abstract

Proteases beyond trypsin are important for protein characterization by mass spectrometry since they help increase sequence coverage and identify post-translational modifications. Like trypsin, the most commonly-used alternative proteases also cleave at charged residues thus there is a need for proteases that cleave at unique sites in the proteome.

Here we describe the characterization of ProAlanase, a protease which preferentially cleaves proteins on the C-terminal side of proline and alanine residues. Digestion with ProAlanase is optimal with short durations of 1-2 hours at acidic pH (~1.5-2.0) which suppresses introduction of sample preparation artifacts and minimizes nonspecific digestion.

The enzyme digested IgG successfully under both reducing and non-reducing conditions, which facilitated characterization of primary structure coverage, PTMs and disulfide bonds. 

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