Elzanowska H, Wolcott R G, Hannum D M, Hurst J K
Department of Chemistry, Biochemistry, and Molecular Biology, Oregon Graduate Institute of Science & Technology, Portland, USA.
Free Radic Biol Med. 1995 Mar;18(3):437-49. doi: 10.1016/0891-5849(94)00150-i.
Various combinations of hydrogen peroxide, reductant (ascorbic acid and superoxide ion), and copper or iron salts and their coordination complexes were examined to determine their cytotoxicity toward several bacteria with diverse metabolic capabilities and cell envelope structures. Four sets of bactericidal conditions were identified, comprising: (1) high concentration levels (5-100 mM) of H2O2 in the absence of exogenous metal ions and reductant; (2) ferrous or ferric coordination complexes plus enzymatically generated O2.- and H2O2 at relatively low steady-state concentration levels; (3) cupric ion plus low concentration levels of H2O2 (1 microM-1 mM) and ascorbate (10 microM-4 mM); (4) cuprous ion (or cupric ion plus ascorbate) in the absence of O2 and H2O2. Rates of losses in viabilities increased proportionately with increases in the concentration of H2O2 in metal-free environments and with each of the components in the Cu2+/ascorbate/H2O2 bactericidal assay system. Oxidant levels required for equivalent killing increased with increasing cell densities of the bacterial suspensions over the range investigated (2 x 10(7)-2 x 10(9) cfu/ml). Other experimental conditions or other combinations of reagents, most notably Fe3+/ascorbate/H2O2 systems, did not generate bactericidal environments. The patterns of response of the three organisms tested, Streptococcus lactis, Escherichia coli, and Pseudomonas aeruginosa, were similar, suggesting common bactericidal mechanisms. However, preliminary evidence suggests that the lethal lesions caused by the various bactericidal conditions are distinct: As discussed, each of the four bactericidal conditions could conceivably be attained within the phagosomes of leukocytes, although none has as yet been identified.
研究了过氧化氢、还原剂（抗坏血酸和超氧离子）以及铜盐或铁盐及其配位络合物的各种组合，以确定它们对几种具有不同代谢能力和细胞包膜结构的细菌的细胞毒性。确定了四组杀菌条件，包括：（1）在没有外源金属离子和还原剂的情况下，高浓度水平（5-100 mM）的H2O2；（2）亚铁或铁配位络合物加上酶促产生的O2.-和相对低稳态浓度水平的H2O2；（3）铜离子加上低浓度水平的H2O2（1 microM-1 mM）和抗坏血酸盐（10 microM-4 mM）；（4）在没有O2和H2O2的情况下的亚铜离子（或铜离子加抗坏血酸盐）。在无金属环境中，存活率的损失率随H2O2浓度的增加以及Cu2+/抗坏血酸盐/H2O2杀菌测定系统中的每种成分成比例增加。在所研究的范围内（2×10(7)-2×10(9) cfu/ml），随着细菌悬液细胞密度的增加，等效杀灭所需的氧化剂水平也增加。其他实验条件或试剂的其他组合，最显著的是Fe3+/抗坏血酸盐/H2O2系统，没有产生杀菌环境。所测试的三种生物体，即乳酸链球菌、大肠杆菌和铜绿假单胞菌的反应模式相似，表明存在共同的杀菌机制。然而，初步证据表明，由各种杀菌条件引起的致死损伤是不同的：如前所述，尽管尚未确定，但四种杀菌条件中的每一种都可以想象在白细胞的吞噬体内实现。
