Cho Jaie Soon, Lee Chang Whan, Kang Seung Ha, Lee Jae Cheon, Bok Jin Duck, Moon Yang Soo, Lee Hong Gu, Kim Sung Chan, Choi Yun Jaie
School of Agricultural Biotechnology, College of Agriculture and Life Science, Seoul National University, 441-744, Suweon, Korea.
Curr Microbiol. 2003 Oct;47(4):290-4. doi: 10.1007/s00284-002-3966-4.
A phytase (EC 3.1.3.8) from Pseudomonas syringae MOK1 was purified to apparent homogeneity in two steps employing cation and an anion exchange chromatography. The molecular weight of the purified enzyme was estimated to be 45 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The optimal activity occurred at pH 5.5 and 40 degrees C. The Michaelis constant (Km) and maximum reaction rate (Vmax) for sodium phytate were 0.38 mM and 769 U/mg of protein, respectively. The enzyme was strongly inhibited by Cu2+, Cd2+, Mn2+, and ethylenediaminetetraacetic acid (EDTA). It showed a high substrate specificity for sodium phytate with little or no activity on other phosphate conjugates. The enzyme efficiently released orthophosphate from wheat bran and soybean meal.
利用阳离子和阴离子交换色谱法分两步将来自丁香假单胞菌MOK1的植酸酶（EC 3.1.3.8）纯化至表观均一。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析，纯化酶的分子量估计为45 kDa。最佳活性出现在pH 5.5和40℃。植酸钠的米氏常数（Km）和最大反应速率（Vmax）分别为0.38 mM和769 U/mg蛋白质。该酶受到Cu2+、Cd2+、Mn2+和乙二胺四乙酸（EDTA）的强烈抑制。它对植酸钠表现出高底物特异性，对其他磷酸盐结合物几乎没有或没有活性。该酶能有效地从小麦麸皮和豆粕中释放出正磷酸盐。
