Loprasert S, Negoro S, Okada H
Department of Fermentation Technology, Osaka University, Japan.
J Gen Microbiol. 1988 Jul;134(7):1971-6. doi: 10.1099/00221287-134-7-1971.
A peroxidase from Bacillus stearothermophilus was purified to homogeneity. The enzyme (Mr 175,000) was composed of two subunits of equal size, and showed a Soret band at 406 nm. On reduction with sodium dithionite, absorption at 434 nm and 558 nm was observed. The spectrum of reduced pyridine haemochrome showed peaks at 418, 526 and 557 nm; the reduced minus oxidized spectrum of pyridine haemochrome showed peaks of 418, 524 and 556 nm with a trough at 452 nm. These results indicate that the enzyme contained protohaem IX as a prosthetic group. The optimum pH was about 6 and the apparent optimum temperature was 70 degrees C. The enzyme was relatively stable up to 70 degrees C; at 30 degrees C it was stable for a month. The enzyme had peroxidase activity toward a mixture of 2,4-dichlorophenol and 4-aminoantipyrine with a Km for H2O2 of 1.3 mM. It also acted as a catalase with a Km for H2O2 of 7.5 mM.
嗜热脂肪芽孢杆菌的一种过氧化物酶被纯化至同质。该酶（分子量175,000）由两个大小相等的亚基组成，在406nm处有一个Soret带。用连二亚硫酸钠还原时，在434nm和558nm处有吸收。还原型吡啶血红素的光谱在418、526和557nm处有峰值；吡啶血红素的还原减去氧化光谱在418、524和556nm处有峰值，在452nm处有一个谷值。这些结果表明该酶含有原卟啉IX作为辅基。最适pH约为6，表观最适温度为70℃。该酶在70℃以下相对稳定；在30℃时可稳定一个月。该酶对2,4-二氯苯酚和4-氨基安替比林的混合物具有过氧化物酶活性，对H2O2的Km为1.3mM。它还作为过氧化氢酶起作用，对H2O2的Km为7.5mM。
