An exo-β-d-glucanase derived from Zea coleoptile walls with a capacity to elicit cell elongation

Cell wall proteins were extracted from maize coleoptiles, Zea mays L. B37 x MO 17, with high concentrations of LiCl. Ion-exchange, chromatofocusing and gel-filtration chromatography were employed extensively to purify exo-β-glucanase activity from the extract. The purified enzyme functioned as an exo-(1→3)-β-glucanase (E.C. 3.2.1.58) and as a glucosidase (E.C. 3.2.1.21) capable of extensive hydrolysis of the native Zea wall (1→3), (1→4)-β- d -glucan, yielding glucose as the final product. The exoglucanase also enhances elongation of maize coleoptile sections in both the presence and absence of exogenous IAA.