Hydrophilic Interaction Chromatography (HILIC) works well for this. Load
your protein on a cartridge (SPE, microcentrifuge spin-type, or Zip
Tip-analog) of PolyHYDROXYETHYL Aspartamide in 70% PrOH containing 10 mM
ammonium acetate or formate, pH 3-5. Detergents will not be retained and can
be flushed out. The protein can then be released with a flush with 50 mM
formic acid (with 10-20% PrOH if needed to keep the membrane protein in
solution). This can also be performed online via LC-MS with an HPLC column
of this material, but it's a lot cheaper to use the cartridges offline. Let
me know if you'd like a free cartridge to try this with.
See Paul Jeno's paper in Anal. Biochem. 215 (1993) 292-8, for an article on
using this method for getting the SDS and salts out of an electroeluted
mitochondrial membrane protein this way. Generally, proteins that don't
normally occur free in aqueous milieu, like membrane proteins and histones,
tolerate HILIC solvents nicely.
Best regards,
Andy Alpert
PolyLC Inc.
9151 Rumsey Road, ste. 180
Columbia, MD 21045
tel: (410) 992-5400 FAX: (410) 730-8340
******************************************************************
<< Subj: MS of Membrane Proteins
Date: 12/10/1999 6:45:07 PM Eastern Standard Time
From: mag4@columbia.edu (Mary Ann Gawinowicz)
Sender: abrf-request@aecom.yu.edu (Association of Biomolecular Resource
Facilities)
To: abrf@aecom.yu.edu (Recipients of ABRF List)
I've been given a membrane protein in detergent solution to run on our
Q-tof, and I'd appreciate any advice on how to get it out of detergent
solution and into a solution suitable for ES. I'm new at running this
instrument and I hope someone out there can give me the benefit of
his/her experience.
Thanks in advance,
Mary Ann Gawinowicz
HHMI/Columbia University
630 W. 168th St.
New York, NY 10032
mag4@columbia.edu