Reagents and materials
Heavy labeled peptides (Thermo PEPotec SRM Peptide Libraries; Grade 2; crude as synthesized), trypsin, mass spectrometry grade, trifluoroacetic acid (TFA), foil heat seals (AB-0757), and low-profile square storage plates (AB-1127) were purchased from Thermo Fisher Scientific (Waltham, MA). Lysyl endopeptidase (Lys-C), mass spectrometry grade was bought from Wako (Japan); sodium deoxycholate, CAA (chloroacetamide), TCEP (tris-2(-carboxyethyl)-phosphine), and triethylammonium hydrogen carbonate buffer (TEAB) (1 M, pH 8.5) were obtained from Sigma (St. Louis, MO). Formic acid (FA), 0.1% FA in acetonitrile, 0.1% FA in water, methanol, and sample preparation V-bottom plates (Greiner Bio-One 96-well Polypropylene Microplates; 651261) are from Fisher Scientific (Pittsburgh, PA). Oasis PRiME HLB 96-well, 30 mg sorbent per well, solid phase extraction (SPE) cleanup…
