Purification and Some Properties of β-Phosphoglucomutase from Lactococcus lactis subsp.cremoris IFO 3427

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β-Phosphoglucomutase(β-PGM, EC 5.4.2.6)was isolated to homogeneity from a cell-free extract of Lactococcus lactis subsp.cremoris IFO 3427 by chromatographies with QAE-Sephadex A-50, phenyl-Sepharose CL-4B, hydroxylapatite, and Bio-Gel A-1.5m. The enzyme was purified about 260-fold with a yield of 7.2% and a specific activity of 113 units/mg protein. The molecular weight was estimated to be 34, 000 and 25, 000 by HPLC gel filtration on TSKgel G3000SW_<XL> and SDS=PAGE, respectively. The enzyme showed optimum activity around pH7.0 and its optimum temperature was about 40℃. The enzyme was stable over a pH range from 5.0 to 9.5 and retained its activity up to 45℃, It was activated by four divalent cations(Co^<2+>>Mn^<2+>MG^<2+>>Ni^<2+> at 1.0mM concentration). The K_m value was 0.23mM for β-_D-glucose 1-phosphate. The enzyme activity was strongly inhibited by other divalent cations(Cu^<2+> Cd^<2+> Zn^<2+> and Hg^<2+>). ADP and ATP also greatly inhibited the enzyme activity, whereas AMP hardly did. _<α-D>-Glucose 1-phosphate and _D-glucose 6-phosphate were not potent inhibitors of the enzyme. A comparison of its characteristics with the properties of other known β-PGMs indicated that the β-PGM from Lactococcus lactis subsp.cremoris IFO 3427 is a new type of enzyme.
公益社団法人日本生物工学会の論文
1998-03-25