Journal
JOURNAL OF MASS SPECTROMETRY
Volume 47, Issue 1, Pages 115-123Publisher
WILEY-BLACKWELL
DOI: 10.1002/jms.2033
Keywords
diglycosyl diacylglycerol; monoglycosyl diacylglycerol; streptococcus pneumoniae; glycolipids; ion-trap mass spectrometry; ESI; lithium adduct ion
Funding
- US Public Health Service (Mass Spectrometry Facility, Washington University) [P41-RR-00954, R37-DK-34388, P60-DK-20579, P30-DK-56341]
- [R01 AI063428-06A1]
Ask authors/readers for more resources
The cell wall of the pathogenic bacterium Streptococcus pneumoniae contains glucopyranosyl diacylglycerol (GlcDAG) and galactoglucopyranosyldiacylglycerol (GalGlcDAG). The specific GlcDAG consisting of vaccenic acid substituent at sn-2 was recently identified as another glycolipid antigen family recognized by invariant natural killer T-cells. Here, we describe a linear ion-trap multiple-stage (MSn) mass spectrometric approach towards structural analysis of GalGlcDAG and GlcDAG. Structural information derived from MSn (n=2, 3) on the [M+Li]+ adduct ions desorbed by electrospray ionization affords identification of the fatty acid substituents, assignment of the fatty acyl groups on the glycerol backbone, as well as the location of double bond along the fatty acyl chain. The identification of the fatty acyl groups and determination of their regio-specificity were confirmed by MSn (n=2, 3) on the [M+NH4]+ ions. We establish the structures of GalGlcDAG and GlcDAG isolated from S. pneumoniae, in which the major species consists of a 16:1- or 18:1-fatty acid substituent mainly at sn-2, and the double bond of the fatty acid is located at omega-7 (n-7). More than one isomers were found for each mass in the family. This mass spectrometric approach provides a simple method to achieve structure identification of this important lipid family that would be very difficult to define using the traditional method. Copyright (C) 2012 John Wiley & Sons, Ltd.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available