Jouve H M, Gaillard J, Pelmont J
Can J Biochem Cell Biol. 1984 Oct;62(10):935-44. doi: 10.1139/o84-120.
Purified catalase from a peroxide-resistant mutant (PR) of Proteus mirabilis displayed great similarities with the bovine liver catalase on the basis of its amino acid composition, content in prosthetic groups, and spectroscopic data. The bacterial enzyme was found to have 2.6 +/- 0.2 mol of protoheme IX per tetramer, with an equivalent amount of titrable iron atoms. The optical absorption of P. mirabilis PR catalase in the presence of various anionic species (cyanide, azide, formate) was examined. The dissociation constant of the formate-enzyme complex was determined as 60 +/- 2 mM at pH 7.5. Inhibition and spectral shifts induced by some thiol compounds were very similar to those reported with mammalian catalase. The electron paramagnetic resonance (EPR) spectra (at 9 GHz and 6 K) of bacterial catalase and its various complexes were reported. Two major different rhombic high-spin ferric signals could be seen in the g = 6 region, using either the pure enzyme or the cell crude extract. The balance between the two rhombic forms was reversibly altered by pH. Various changes in rhombicity were also observed after binding with anionic ligands. The EPR spectrum (at 40 K) of nitrosyl ferrous catalase was very similar to reported data with horse liver catalase.
奇异变形杆菌的过氧化物抗性突变体（PR）纯化的过氧化氢酶，基于其氨基酸组成、辅基含量和光谱数据，与牛肝过氧化氢酶表现出极大的相似性。发现该细菌酶每个四聚体含有2.6±0.2摩尔的原卟啉IX，以及等量可滴定的铁原子。研究了奇异变形杆菌PR过氧化氢酶在各种阴离子（氰化物、叠氮化物、甲酸盐）存在下的光吸收。在pH 7.5时，甲酸盐 - 酶复合物的解离常数测定为60±2 mM。一些硫醇化合物诱导的抑制作用和光谱位移与哺乳动物过氧化氢酶报道的非常相似。报道了细菌过氧化氢酶及其各种复合物的电子顺磁共振（EPR）光谱（9 GHz和6 K）。使用纯酶或细胞粗提物，在g = 6区域可以看到两个主要不同的菱形高自旋铁信号。两种菱形形式之间的平衡随pH可逆变化。与阴离子配体结合后，还观察到菱形度的各种变化。亚硝酰亚铁过氧化氢酶的EPR光谱（40 K）与马肝过氧化氢酶报道的数据非常相似。
