membrane spanned peptides
Suming Hua (shua@umaryland.edu)
Wed, 13 May 1998 15:30:57 -0400 (EDT)
I have a problem regarding separation and purification of membrane spanned
peptides with RP-HPLC. I labeled calcium ATPase on the membrane domain,
then removed the cytosolic parts of the enzyme with trypsin digestion, and
pelleted the membrane parts which was dissolved in formic acid, then
filtered. The labeled peptide was separated and collected with c-18 column
using TFA-acetonitrile system. When I did further purification, the
peptide was stuck in the column and nothing came off at all. I don't know
if there are any other methods to deal with the membrane peptides using
HPLC system.
How can I identify the labeled peptide in the mixture with mass
spetrometry (the molecular weight of this peptide is 7-8K)? Is it possible
to load the mixture on mass spectrometer directly? Thank you in advance
for your kind advices.