Is EDTA a protease inhibitor - a potentially stupid question (Mar/06/2006 )
i am trying to extract a membrane protein from the pancreas, and need some protease inhibitors. Is EDTA enough or do i need to invest in some?
i think that edta is just a metal ion chelator. i guess it can be used in the case of metalloproteases (theoretically it should work) though i'm really not sure. but you've probably got a whole bunch of different types of protease in the cell which aren't dependent on metal ions for their activity.
i use PMSF when i extract proteins from E.coli. protease inhibitor cocktails are also commercially available. perhaps it would be safer to invest in some.
EDTA can reduce protease activity... but not at all.
Typically, i would say that you notice that it's inhibitor when you do PCR assays, but not inhibitor when you extract proteins and forgot your protease inhibitor.
Btw, when very low amounts of salts are in the solution, inhibitory potential is greater than in normally-salts-concentrated solutions