Chemistry Reference
In-Depth Information
Figure 5.5
MS analysis of glycans. (a) Mass
spectrum of pyridylaminated monosialyl-bian-
tennary glycan using ESI-MS in negative mode,
which is effective for the analysis of sialyl-
glycans. Mass number provides information on
sugar composition, but the isomers present the
same spectra. (b) MS/MS analysis of isomers
of monosialyl-biantennary glycans. The peak of
at 1003.9 in (a) was degraded and analyzed
GlcNAc - Man fragment, detected at
m
/
z
= 835.2.
The
α
6Man branch was cleaved at the
β
Man
residue and formed a NANA - Gal - GlcNAc - Man -
Man fragment, detected at
m
/
z
= 979.3. In this
way we can determine which branch was NANA
linked. (c) MS
3
analysis of the
m
/
z
= 835.2 frag-
ment in (b). NANA
α
2,3Gal is cleaved more
easily than is NANA
α
2,6Gal, thus we can deter-
mine the type of NANA linkage. Data provided
by Dr K. Deguchi.
