Abstract
Maltase was purified from chick intestinal mucosa and its properties were compared with other species.
1. Chick intestinal maltase was purified from the papain-solubilized intestinal mucosa by ammonium sulfate fractionation, Sephadex G-200 column chromatography and DEAE Sephadex A-25 ion exchange column chromatography. The chick intestinal maltase was slightly retained on Sephadex G-200 column, although sucrase-isomaltase complex was not.
2. The molecular weight of the maltase was estimated as 260, 000 by polyacrylamide disc gel electrophoresis.
3. Km value of the maltase was 4.2mM and Vmax value was 488 μmol-substrate hydrolyzed/mg protein/hr. The maltase activity was competitively inhibited by Tris, K1 value of which was 51.6mM. Furthermore, the maltase activity was inhibited completely by the heavy metal ions Ag+ and Hg2+, and partially by Cu2+ and Zn2+. Optimal pH of the enzyme was 6.0.
