Sequencing grade lys c

All chemicals were of analytical reagent
(AR) grade. Ethylene glycol-bis(2-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), dithiothreitol (DTT), iodoacetamide,
bovine catalase, tris(hydroxymethyl)aminomethane hydrochloride
(Tris·HCl), tris(hydroxymethyl)aminomethane (Tris·base),
and HEPES were purchased from Sigma-Aldrich (St. Louis, MO, USA).
KCl, MgCl₂, CaCl₂, and H₂O₂ (30% solution) were purchased from Columbus Chemical Industries
(Columbus, WI, USA). Dimethylformamide (DMF) was from Jade Scientific
(Canton, MI, USA). Glacial acetic acid and water (HPLC grade) were
from Mallinckrodt Chemicals (Phillipsburg, NJ, USA). Acetonitrile
(HPLC grade) and iodomethane were purchased from EMD Chemicals (San
Diego, CA, USA). Sodium hydroxide (NaOH) and formic acid were from
Spectrum Chemical Mfg. (Gardena, CA, USA). Trifluoroacetic acid (TFA)
was purchased from Pierce (Rockford, IL, USA). Mass spectrometry grade
Glu-C was purchased from Thermo Fisher Scientific (Waltham, MA, USA).
Sequencing grade modified trypsin was from Promega (Madison, WI, USA).
Sequencing grade Lys-C was obtained from Roche Diagnostics (Indianapolis,
IN, USA). Human calcineurin was prepared as previously described.^{27 (link)} DMBNHS was prepared via a three-step process
as described previously.^{31 (link)}