fluorogenic/chromogenic invertase substrate??

[David Singleton]

Sebastian Springer (springer at uclink4.berkeley.edu) wrote:
: Invertase, which I want to assay, is a
: glucosyl-beta-D-fructofuranosidase. Is anyone aware of a substrate for
: this enzyme which would give rise to a fluorescent or coloured product?
: There are similar reagents for glucosidases (e.g.
: 4-nitrophenyl-beta-D-glucoside or fluoresceinyl-beta-D-glucoside) or
: mannosidases, but I have found no fructosides in the catalogs. 
: Failing that, synthesis advice for a fluoresceinyl fructoside would be
: appreciated.
Second try at a followup with a new newsreader. Does this assay need to be
direct? I used a peroxidase coupled assay that yielded oxidized
o-dianisidine, which can be followed colorimetrically. Reference is
Goldstein and Lampen, Meth Enzymology 42:504

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* David R. Singleton                 drs3y at virginia.edu *
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