Autori: A.Serb, C.Schiopu,C.Flangea,E. Sisu,A.D.Zamfir
Editorial: John Wiley & Sons, J. Mass. Spectrom., 44, p.1434-1442, 2009.
We developed a straightforward approach for high-throughput top-down glycolipidomics based on fully automated chipnanoelectrospray
(nanoESI) high-capacity ion trap (HCT) multistage mass spectrometry (MSn) by collision-induced dissociation
(CID) in the negative ion mode. The method was optimized and tested on a polysialylated ganglioside fraction (GT1b), which
was profiled by MS1 and sequenced in tandem MS up to MS6 in the same experiment. Screening of the fraction in the MS1
mode indicated the occurrence of six [M− 2H]2− ions which, according to calculation, support 13 GT1 variants differing in their
relative molecularmass due to dissimilar ceramide (Cer) constitutions. By stepwise CID MS2-MS5 on the doubly charged ion at
m/z 1077.20 corresponding to a ubiquitous GT1b structure, the complete characterization of its oligosaccharide core including
the identification of sialylation sites was achieved. Structure of the lipid moiety was further elucidated by CID MS6 analysis
carried out using the Y0 fragment ion, detected in MS5, as a precursor.MS6 fragmentation resulted in a pattern supporting a
single ceramide form having the less common (d20 : 1/18 : 0) configuration. The entire top-down experimentwas performed in
a high-throughput regime in less than 3min of measurement, with an analysis sensitivity situated in the subpicomolar range.
Cuvinte cheie: top-down glipidomica.chip-nano-ESI-HCIT-MS. Fragmentari multiple.Secventializarea oligozaharide.Fragmentare ceramida // top-down glycolipidomics; fully automated chip-nanoESI; multistage collision-induced dissociation; ganglioside oligosaccharide sequencing; ceramide fragmentation; high throughput