Purification of Tetragalloylglucose 4-O-Galloyltransferase and Preparation of Antibodies against This Key Enzyme in the Biosynthesis of Hydrolyzable Tannins

The enzyme, ß-glucogallin: 1,2,3,6-tetra-O-galloyl-ß-D-glucose 4-O-galloyltransferase, which catalyzes the last common step in the biosynthesis of the two subclasses of hydrolyz­ able tannins, i.e. gallotannins and ellagitannins, was purified 868-fold from leaves of peduncu­ late oak ( Quercus robur, syn. Q. pedunculata) to apparent homogeneity. Polyclonal antibod­ ies against this pivotal enzyme were raised in rabbits and purified by protein-A chromatography, gel-filtration and affinity complexation. They were found to react specifi­ cally with acyltransferase from oak, displaying no cross-reactivity towards analogous enzymes from other plants synthesizing hydrolyzable tannins along the same biogenetic route, e.g. Rhus typhina or Tellima grandiflora.