Abstract
The amylomaltase from Escherichia coli IFO 3806 was purified to homogeneity seen by SDSpolyacrylamide gel electrophoresis after DEAE-Sephadex, Ultrogel AcA 44, hydroxylapatite, and 1, 6-hexane-diamine-Sepharose 4B column chromatographies. The molecular weight of the purified enzyme was 93, 000 by SDS-polyacrylamide gel electrophoresis. The enzyme was most active at pH 6.5 and at 35°C, and stable up to 45°C at pH 7.0 and from pH 6.0-7.3 at 40°C on 30min incubation. The enzyme acted on maltotetraitol, maltopentaitol, and maltosylsucrose besides maltooligosaccharides, but did not act on maltitol, maltotriitol, glucosylsucrose, isomaltose, panose, isopanose, or isomaltosylmaltose. This enzyme did not catalyze hydrolytic action on maltotetraitol, maltopentaitol, or maltosylsucrose.
