Lipopeptides like this can conveniently be analyzed and purified by
Hydrophilic Interaction Chromatography (HILIC). One applies the peptide
mixture to a very polar column material in a mostly organic solvent (@ 90%
acetonitrile or propanol in the case of lipopeptides) and runs a decreasing
organic solvent gradient. Peptides elute in order of increasing polarity, the
opposite of reversed-phase HPLC. The column will ignore the hydrophobic
residues and acyl- groups; retention is through the polar residues (Ser-,
Lys-, etc.).
Introduction to HILIC: J. Chromatogr. 499 (1990) 177.
An example of HILIC of an integral membrane protein: Anal. Biochem. 215 (1993)
292.
Determining the location of each acyl- group: Sorry; can't help you with this.
Let me know if you want more details about the chromatography.
Best regards,
Andy Alpert
PolyLC Inc.
9151 Rumsey Road, ste. 180
Columbia, MD 21045
tel: 410-992-5400 FAX: 410-730-8340 e-mail: PolyLC@aol.com