Dear All-
I am working on a phosphorylation site project. I've tried to use phosphatase (CIP) to
determine the number of phosphates in the protein and in its tryptic peptides. However, the
CIP we got from NEB is stored in 50% glycerol and 10 mM Tris buffer. My questions are:
1. How to remove glycerol from the sample after incubating my protein with CIP? I have tried
C4 ziptip without much luck at recovering my 30 kd protein.
2. How to remove glycerol from hydrophilic peptides derived from phosphatase treatment of
the trypsin digest of the 30 kD protein mentioned above? I've successfully used C18 ziptip
at recovering larger/hydrophobic peptides. But smaller/hydrophilic peptides did not bind,
and are still mixed with glycerol in the 0.05% formic acid wash fraction from the ziptip.
Thanks for your input!
Hong Li
MS Core Facility
NJ Medical School
Newark
This archive was generated by hypermail 2b29 : Wed Nov 21 2001 - 14:16:55 EST