GingisREX: A Complementary Enzyme for the Detection\nof Bacterial Proteins

Reliable\nenzymatic digestion underscores successful mass-spectrometry-based\nproteomics experiments. In this study, we compare the use of the arginine-specific\nprotease, GingisREX, against a more traditional approach in the identification\nof <i>Escherichia coli</i> proteins. An increased number\nof protein identifications were noted when GingisREX was used compared\nto a trypsin/lys-C mixture. This improvement was attributed to the\ngeneration of fewer peptides per protein, resulting in a simpler peptide\nmixture. Furthermore, GingisREX exhibited increased digestion efficiency,\nfewer missed cleavages, and improved MS/MS data quality for higher\nmolecular weight peptides. The data here establish GingisREX to be\na protease complementary to trypsin for enhanced detection of bacterial\nproteins. With further optimization, GingisREX could prove to be an\neffective alternative to trypsin for identifying host cell proteins\nin biotherapeutics.