Emeruwa A C
Ann Microbiol (Paris). 1981 Nov-Dec;132 B(3):289-98.
Intracellular alkaline phosphatase (Apase) produced during growth of Nocardia asteroides in dephosphated nutrient broth supplemented with 1% glucose and some properties of the purified enzyme were studied. Filamentous cells of N. asteroides synthetized the Apase in high yields (7.0 x 10(3) units/mg cell protein) during exponential growth phase. The intracellular level dropped drastically and the extracellular amounts increased during stationary phase, probably due to the loss of the enzyme in the medium because of the fragmentation of the filamentous cells into rod-like and spherical forms and/or due to cell lysis. The purified enzyme showed typical Apase activity with optimal pH at 10 and optimal temperature at 37 degrees C. The Km of the enzyme for p-nitrophenyl phosphate was close to the value reported for Apase from other sources. Other properties of the enzyme which resembled those from other species included respectively the uncompetitive, non-competitive and competitive inhibition of L-phenylalanine, urea and inorganic phosphate. The effect of these compounds on the enzyme may be useful in the regulation of Apase activity in vivo and hence may play a vitalrole during morpho genesis of N. asteroides.
研究了星形诺卡氏菌在添加1%葡萄糖的脱磷营养肉汤中生长过程中产生的细胞内碱性磷酸酶（Apase）以及纯化酶的一些特性。星形诺卡氏菌的丝状细胞在指数生长期高产合成Apase（7.0×10³单位/毫克细胞蛋白）。在稳定期，细胞内水平急剧下降，细胞外量增加，这可能是由于丝状细胞破碎成杆状和球状形式导致酶在培养基中损失和/或细胞裂解。纯化的酶表现出典型的Apase活性，最适pH为10，最适温度为37℃。该酶对磷酸对硝基苯酯的Km值接近其他来源报道的Apase的值。该酶的其他特性与其他物种的特性相似，分别包括L-苯丙氨酸、尿素和无机磷酸盐的非竞争性、非竞争性和竞争性抑制。这些化合物对酶的作用可能有助于体内Apase活性的调节，因此可能在星形诺卡氏菌的形态发生过程中起重要作用。
