Protease and Phosphatase Inhibitor Cocktail

Mass spectrometry (MS) compatible protease inhibitor cocktail and phosphatase inhibitor cocktail, with broad specificity for the inhibition of:

• Serine, cysteine and aspartic proteases, and metalloproteases
• Tyrosine, serine/threonine, acid and alkaline phosphatases

All inhibitors and fillers were chosen so as not to interfere with LC-MS analyses. Any inhibitors capable of covalent, irreversible protein modification were avoided. This cocktail is EDTA-free. All inhibitors were selected to allow facile downstream sample processing, such as immobilized metal affinity chromatography (IMAC) for His-tagged protein purification and, uniquely, phosphopeptide enrichment.

Tested in mammalian cell lysates and liver tissue extracts. Designed for use in samples to be analyzed by mass spectrometry.

MS-SAFE Protease and Phosphatase Inhibitor has been used to measure ribosomal protein S6 kinase (S6K) activity.

Protease inhibitors: serine, cysteine and aspartic proteases, and metalloproteases
Phosphatase inhibitors: tyrosine, serine/threonine, acid and alkaline phosphatases

Comprehensive protease and phosphatase inhibitor cocktail for mass spectrometry analysis

Compatible with downstream sample processing such as His-tagged protein purification and phosphopeptide enrichment

Allows accurate measurement of protein activity and identification of phosphorylation sites.

Lyophilized powder that is water-soluble

One vial makes 20 mL of 1× inhibitor cocktail working solution, using either water or extraction/lysis buffer. Alternatively, a 10× concentrated solution may be prepared by adding 2 mL of water or extraction/lysis buffer. This 10× solution may then be diluted 10-fold into extraction/lysis buffer as needed for a 1× working solution.

Protease inhibitors:

• Bestatin hydrochloride
• Leupeptin
• Phosphoramidon disodium salt
• Pepstatin A
• Elastatinal
• Aprotinin
• Nafamostat mesylate
• Antipain

Phosphatase inhibitors

• Okadaic acid
• Sodium fluoride
• Sodium orthovanadate
• Bromotetramisole oxalate

Fillers

• β-lactose
• DL-leucine