_??_ties of Maltose Phosphorylase from Lactobacillus brevis

Abstract

Maltose phosphorylase (EC 2. 4. 1. 8) from Lactobacillus brevis was purified 29-fold over the crude extract. The final preparation was at least 80% pure and had a specific activity of 18units/mg protein. The molecular weights of the native enzyme and of the component dissociated in sodium dodecyl sulfate were 150, 000 and 80, 000, respectively. The enzyme does not contain pyridoxal-5'-phosphate as a cofactor. It can not act on maltitol, maltotriitol, sucrose, lactose and trehalose, and essentially not on isomaltose, maltobionic acid, maltotriose and maltotetraose. Inhibitory effect was observed with CuSO4, HgCl2 and p-chloromercuribenzoate. Some other properties were also examined. A possibility of using this enzyme for the analysis of maltose was proposed.