tryptic digest
Peter Hunziker (phunzi@bioc.unizh.ch)
Thu, 19 Nov 1998 08:37:02 +0100
long time ago my supervisors teached me that trypsin does never cleave the
peptide-bond between LYS/ARG and PRO. Now, I also tell my students that
this bond is not cleaved at all. However, in a recent LC/MS analysis we
measured the masses of two peptides that indicated a tryptictic cleavage
exactly at this bond (Enzyme: mod. trypsin from Promega). Since I could not
believe it we additionally sequenced the peptides by Edman degradation and
it turned out that trypsin has cleaved the LYS-PRO bond.
On the C-terminal side of the cleavage site there were a number of GLY
residues. Does anybody know if this may influences the specificity of the
enzyme? Were my supervisors wrong and trypsin does cleave LYS/ARG-PRO bonds?
best regards
Petre
**************************************************************
Dr. Peter Hunziker | E-Mail: phunzi@bioc.unizh.ch
Universitaet Zuerich |
Biochemisches Institut | Tel: +41-1-635 55 20
Winterthurerstr. 190 | Fax: +41-1-635 68 05
CH-8057 Zuerich, Switzerland |
**************************************************************
Visit our homepage: http://www.unizh.ch/~phunzi
**************************************************************