β-apiosyl-β-glucosidase

The enzyme from the tropical tree Dalbergia nigrescens Kurz belongs inglycosyl hydrolase family 1. The enzyme removes disaccharides from the natural substrates dalpatein 7-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside and 7-hydroxy-2',4',5',6-tetramethoxy-7-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (dalnigrein 7-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside) although it can also remove a single glucose residue from isoflavonoid 7-O-glucosides. Daidzin and genistin are also substrates. Reaction: 7-[β-D-apiofuranosyl-(1→6)-β-D-glucopyranosyloxy]isoflavonoid + H2O = a 7-hydroxyisoflavonoid + β-D-apiofuranosyl-(1→6)-D-glucose