Table I.
Effect of different xyloglucan donor substrates on LeXET2 activity
| Donor Substrate | Fucose | XET Activity |
|---|---|---|
| % | ||
| Tamarind seed xyloglucan | No | 16 |
| Bean suspension-cultured cells xyloglucan | Yes | 14 |
| Sycamore suspension-cultured cells xyloglucan | Yes | 16 |
| Tomato suspension-cultured cells xyloglucan | No | 66 |
Reactions containing 100 μg of donor substrate, 282 pmol XLLG-APTS, and 50 ng of recombinant LeXET2 protein in a total volume of 40 μL were incubated for 1 h at 25°C and were analyzed by gel permeation chromatography on a Superdex-75 column as described in “Materials and Methods.” Fluorescent transglycosylation products were detected in the eluate with a fluorescent detector. XET activity was expressed as a percentage of the peak area of the high-Mr fluorescent transglycosylation products relative to the total peak area of all fluorescent derivatives.