Canadian group of Prof. Ole Hidsgaul has recently reported the
use of tetramethylrhodamine as the fluorescent label on
oligosaccharides for the assay of both glycosidases and
glycosyltransferases. This is probably the most sensitive
method reported todate. Detection of 100 molecules of enzyme
substrate product can be achieved by using capillary
electrophoresis with laser-induced fluorescence detection.
Following are the references:
Glycobiology, 4 (1994) 239-242
Anal. Biochem., 227 (1995) 368-376
Anal. Biochem., 205 (1992) 108-114 (Label: ANDA)
J. Chromatography B, 657 (1994) 307-313
Complex Carbohydrates in Drug Research (Alferd Benzon Symposium
36), K. Bock and H. Clausen, Eds., Munksgaard Intl. Publ.,
Copenhagen, (1994) 104-113.
In addition to the above labels, Pyridylamino-oligosaccharides
can also be used as substrates as suggested by Ian Wilson.
Shaheer H. Khan
Foster City, CA
Disclaimer: Only and Only my opinion, my employer has nothing
to do with it.
I have noticed that one can use commercially available
AMC-labelled oligosaccharides as substrates
for glycosidase assays.
My question is whether there is any experience around with
using similarly labeelled
oligosaccharides as substrates for glycosyltransferases. If yes
then how far the label should
be from the reaction centre and what might be the optimal
method for following the reaction, e.g.
TLC or HPLC.I am mostly thinking about assaying the activity
of alpha- galactosyl transferase.
Armin Sepp, PhD
Armin.Sepp at bbsrc.ac.uk