GRS Protease Inhibitor Cocktail is a mix of several compounds that inhibit protease activity and is being used to protect against undesired protein digestion that occurs during and after cell lysis. The presence of EDTA assures greater inhibition of metalloproteases.
The GRS Protease Inhibitor Cocktail (with EDTA) comprises 100mM PMSF, 100mM EDTA, 2mM Bestatin, 0.3mM Pepstatin A, and 0.3mM E-64, dissolved in DMSO containing a small amount of deionized water.
PMSF (PhenylMethylSulfonyl Fluoride) is a serine protease inhibitor with an effective concentration of 0.1-1mM and a short half-life in aqueous solutions (ranging from ~2 hours at pH 7 to ~30 min at pH 8). Bestatin (Ubenimex) is a competitive, reversible protease inhibitor, derived from Streptomyces olivoreticuli, which has been shown to inhibit the enzymatic degradation of oxytocin, vassopresin, and several other peptides and compounds. Pepstatin A is a hexapeptide containing the uncommon aminoacid statine and is a very potent inhibitor of aspartyl proteases, as well as of some aspartic proteases such as Pepsin and Cathepsins D and E. And E-64 is an epoxide isolated from Aspergillus japonicas that irreversibly inhibits many cysteine proteases such as papain, calpain, staphopain and cathepsins B and L.