Chymotrypsin has never cleaved at Asp or Glu in my hands. On the contrary,
neighbouring charges act to prevent other cleavages. I have not seen a
cleavage at Ala either. Of course, we have used bovine chymotrypsin. Maybe
the manufacturer is selling cockroach trypsin????
Ken
Kenneth A. Walsh
E.W.Davie/ZymoGenetics Chair of Biochemistry
Box # 357350
University of Washington
Seattle WA 98195
walsh@u.washington.edu
Phone 206-543-1768
FAX 206-685-9231
On Thu, 25 Sep 1997, Kenneth Williams wrote:
> The product literature with our sequencing grade chymotrypsin states this
> enzyme cleaves at Tyr, Phe, Trp and (at a lower rate) at Leu, Met, Ala, Asp
> and Glu. Has anyone documented reasonable rates of cleavage at Asp/Glu?
> Is there a good reference(s) that documents relative rates of cleavage at
> different residues in intact, denatured proteins?
>
> Thanks,
> Ken Williams
>
>