Re[2]: Digestion of Toxin, Glu-C at low pH

Katheryn Resing (Katheryn.Resing@Colorado.EDU)
Thu, 4 Mar 1999 13:39:24 +0000

I didn't mean to imply V8 worked at low pH, just that if her protein had an
acidic pI, then V8 might give a better digestion than trypsin. I have had
reasonable luck with V8 cleaving a knotted growth factor, where trypsin did
not touch it. In the second paragraph, I said that she might try pepsin
under acidic conditions, which actually works very well on knotted
peptides.

With regard to the acidic pH results shown for V8 in the literature, I
believe that this may be a different form of the enzyme than is now
commercially sold as V8. The V8 I used 10 years ago was rather
heterogeneous on gels and that heterogeneity probably explains much of the
confusion around the specificity and properties of this enzyme. In fact,
even now, V8 from different sources will show different results.

Katheryn