Preparation of a new chromogenic substrate to assay for beta-galactanases that hydrolyse type II arabino-3,6-galactans
Naomi X-Y Ling, Filomena Pettolino, Ming-Long Liao, Antony Bacic
Carbohydrate Research | ELSEVIER SCI LTD | Published : 2009
A chromogenic assay using RB5-dGA, Reactive Black 5 (RB5) dye covalently coupled to de-arabinosylated gum arabic (dGA), was developed for rapid screening of beta-galactanases. dGA was prepared by partial acid hydrolysis (0.25M trifluoroacetic acid for 2h at 90-95 degrees C) of gum Arabic (GA) from Acacia senegal. The dGA exhibited a median molecular mass of approximately 10kDa, corresponding to a degree of polymerisation (DP) approximately 60. It was devoid of Ara residues, and contained mostly Galp (68mol%) together with GlcpA (30mol%). The Galp residues were (1,6)- (34mol%), (1,3)- (3mol%) and (1,3,6)- (26mol%) linked, and the GlcAp residues were primarily terminal (28mol%) together with a..View full abstract
This project was supported by funds from the Co-operative Research Centre (CRC) for Bioproducts and Melbourne International Research Scholarship (MIRS).