Cesium ion liquid secondary ion mass spectrometry of membrane-bound glycoproteins: structural and topological considerations of acetylcholine receptor from Torpedo californica.
We report mass mapping of a large (270 kD) multisubunit membrane bound glycoprotein, nicotinic acetylcholine receptor from Torpedo californica, using enzymic digests of the affinity purified whole receptor and cesium ion liquid secondary ion mass spectrometry. Peptides, glycopeptides and derivatized N-linked oligosaccharides were isolated by HPLC and identified by LSIMS. We have shown that mass spectrometric sensitivity is improved a hundred-fold through use of computer-controlled mass window stepping of an electro-optical multichannel array detection system on a LSIMS double focusing mass spectrometer. This new method permitted determination of the complete fragmentation pattern of Man8N2-ABEE using only 5 picomoles of sample.
Poulter
L
L
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143.
Earnest
J P
JP
Stroud
R M
RM
Burlingame
A L
AL
D000595:Amino Acid Sequence; D000818:Animals; D002586:Cesium / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis*; D013058:Mass Spectrometry; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D011950:Receptors, Cholinergic / Q000032:analysis*; D014101:Torpedo / Q000378:metabolism*
D006023:Glycoproteins; D011950:Receptors, Cholinergic; D002586:Cesium