Purification of an arbuscular mycorrhizal endoglucanase from onion roots colonized by Glomus mosseae

An arbuscular endoglucanase (EC 3.2.1.4) was purified to homogeneity from roots of onion (Allium cepa cv. Babosa) colonized by the arbuscular mycorrhizal fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe. The stepwise purification procedure consisted of Filtron concentration (10 kDa), anion-exchange chromatography, anion-exchange fast protein liquid chromatography, and electroelution from polyacrylamide gels. Pure endoglucanase had a specific activity of 2500 units mg−1 protein, and was purified 198-fold with a yield of 0.6 μg enzyme g−1 root. The endoglucanase has a relative molecular weight of about 27 kDa, and behaves as a monomer in its native form.