Environmental Engineering Reference
In-Depth Information
Fig. 8.12 Automated chip-based (-) nanoESI QTOF MS of
BPy O
-glycopeptide mixture. Sample
concentration: 3 pmol
l
1
, in methanol. Signal acquisition: 1.3 min. Reprinted with permission
μ
from [
67
]
reduced number, the dominating species were those with shorter chains (up to
hexasaccharide units) and lower degree of sialylation.
In the first study [
67
], complex carbohydrate mixtures from the urine of a patient
suffering from hereditary
N
-acetylgalactosamine deficiency (Schindler
s disease)
was submitted to glycoscreening by fully automated chip-based (-) nanoESI QTOF
MS. Using a sample concentration of about 3 pmol
'
l
1
for
BPy
fraction of
O
-glycopeptide mixture extracted from the urine of a patient suffering from Schin-
dler disease, the mass spectrum displayed a high level of heterogeneity concerning
the glycan chain lengths, originating from tri- up to decasaccharide units
O
-linked
either to Ser, Thr, or the threonine-proline (Thr-Pro) dipeptide (Fig.
8.12
). Remark-
ably, in such a configuration, a high signal/noise ratio could be obtained within only
30 s of acquisition. CID at variable collision energies (VE-CID) was further used
for the fragmentation of the disialooctasaccharide
O
-linked to Ser at
m
/
z
890.32
(Fig.
8.13
).
MS experiments carried out under the same conditions of sample solution and
ionization/detection indicated a run-to-run and nozzle-to-nozzle reproducibility of
nearly 100 %. At the same time, this approach significantly improved the speed in
sample delivery and data collection, simplified the sample handling steps and
minimized the analyte loss.
μ
