Methylated trypsin - Enhanced trypsin on a budget: Stabilization, purification and high-temperature application of inexpensive commercial trypsin for proteomics applications

HCP analysis of the various trypsins was performed using the X! Tandem search engine (Alanine) (http://www.thegpm.org). All data was searched against the downloaded UniProt Sus scrofa proteome (40.706 sequences, March 10, 2019) and the most recent cRAP list (http://www.thegpm.org). Data were search as: enzyme: semi-tryptic, parent ion error: 10 ppm, fragment error: 0.1 Da, max e-value: 0.01, fixed modifications: carbamidomethylation (C), partial modifications: oxidation (M), methylation (K), dimethylation (K). Each triplicate set of result files were then analyzed through PeptideShaker 1.16.38 [26] and reported at 1% FDR.