Ch. Scaman et al., SYNTHESIS OF ALPHA-D-GLCP-(1 -] -ALPHA-D-GLCP-(1-]3)-ALPHA-D-GLCP-O-(CH2)(8)COOCH3 FOR USE IN THE ASSAY OF ALPHA-GLUCOSIDASE-I ACTIVITY, Carbohydrate research, 296, 1996, pp. 203-213
The chemical synthesis of alpha-D-Glcp-(1 --> 2)-alpha-D-Glc p-(1 -->
3)-alpha-D-Glcp-O-(CH2)(8)COOCH3 (9), a substrate specific for cr-gluc
osidase I, is reported. This enzyme removes the terminal alpha-D-Glcp
unit to produce alpha-D-Glcp-(1 --> 3)-alpha-D-Glcp-O-(CH2)(8)COOCH3 (
10). This is the first synthetic substrate described for glucosidase I
that allows kinetic evaluation of substrates and inhibitors of this e
nzyme. Tetramethylrhodamine was coupled to 9 through an ethylenediamin
e linker to produce a brilliant red derivative. Addition of this fluor
escent dye did not affect enzyme binding to the substrate, as determin
ed by a comparison of the K-m value (1.3 mM). The fluorescent label al
lows visual detection of 2-3 pmol of product by TLC. (C) 1996 Elsevier
Science Ltd.