Fucosylated
structures participate in a wide range of cell-cell, cell-protein,
and protein-protein recognition processes in Eukaryotes and
Prokaryotes. In invertebrates, fucosylated glycans are
particularly connected with their ability to initiate allergic
reaction in mammals (for example bee venom). In ticks, the importance
of fucosylated glycans
for their infection by Anaplasma
marginale bacteria was presented
suggesting the importance of these specific glycan structures for the
transmission of pathogens by ticks.
In
this regard, the occurrence and function of fucosylated
glycans/glycoproteins in ticks is poorly understood. Moreover, host
proteins from the blood meal were shown to outlast the molting of
ticks into the next life-stage and thus, the origin of the observed
glycans cannot be attributed to ticks simply based on their presence.
For this reason, we employed
bioorthogonally modified saccharide (fucose-alkyne) in the blood used
for in vitro
feeding of adult Ixodes ricinus females
that was directly incorporated into glycans. The alkyne group can be
further reacted using Click chemistry (with biotin-azide) and
detected with an appropriate system (conjugated to streptavidin).
Using bioorthogonal chemistry, we detected the fucosylated molecules
which are produced by the tick and not by the host.
We
detected strong staining of bioorthogonally labeled fucosylated
glycans in tick tissues using fluorescent and electron microscopy.
Fucosylated structures were found in high
abundance in the gut, salivary glands, ovaries, and malpighian
tubules. Some of these glycoproteins were also isolated and
identified using mass spectrometry.
