We are working on a lipoprotein whose first residue is Cys. Based on mass
spec results, we deduced that there are three fatty acids attached to the
Cys,
one at N-terminal amino group and the other two, at Cys side chain through
two fatty acid esters of glycerol. We deduced that two of the lipid tails
are C16 long and another, C18 long. We would like to know exact length and
exact location of each lipid tail.
Peptide mapping of this protein by LC-MS (C4, C8, C18 RP-columns have tried)
showed all peptides expected except the N-terminal lipidated peptide due to
extremely high hydrophobicity of the peptide. As the results the peptide
can't be eluted from columns. Our questions are
1. What columns can be used for analyzing such hydrophobic peptide?
2. What is the best way to study structure of such lipid tails of a protein?
By checking biochemistry book, we found that an enzyme called lipoprotein
lipase can hydrolyze triacylglycerols to fatty acids and glycerol under
activation of apo-C-II. Has anybody out there tried such enzyme (commercial
available) on lipoprotein?
Any suggestions are appreciated.
Gejing
Gejing Deng
Astra Research Center Boston, Inc.
128 Sidney street
Cambridge, MA 02139
Tel: 617-234-2560
Fax: 617-576-3030
E-mail: gejing.deng@arcb.us.astra.com