Hi Matthew,
TEV is probably the least robust protease
among those commonly used for tag removal. Here¡¯s a common unit definition of
TEV. One unit (corresponding to 0.1 ug TurboTEV) cleaves ¡Ý85% of 3 ¦Ìg control
substrate in 1 hour at 30C. You need to use really a lot of TEV. Information
collected from our customers shows large variation in quality of home-made TEV
proteases. Some used 1:5 w:w ratio.
Adding a little bit EDTA to Ni pool helps
TEV digestion. You can find a general protocol at http://www.accelagen.com/TurboTEV-protocol.htm.
Cheers,
Chun
Accelagen
From: CCP4 bulletin
board [mailto:[log in to unmask]] On
Behalf Of Matthew Merski
Sent: Monday, May 24, 2010 9:28 AM
To: [log in to unmask]
Subject: [ccp4bb] TEV cleavage
problems
Hello all,
I am working with a protein that is expressed as with an N-terminal
domain that is normally cleaved for activation of the protein (and
crystallization). For in vitro reasons I've needed to switch the normal site to
a TEV site. However, even though the TEV site is in the same place as the
original proteolytic site, I have been unable to get cleavage despite using a
lot of TEV at 37 C, pH 8.0. Has anyone been able to overcome a similar
problem?
Matthew Merski
Post-doctoral researcher
UCSF