The chemical modification of bacterial components was studied following incubation of
Escherichia coli
with the peroxidase-hydrogen peroxide (H
2
O
2
)-iodide (I
−
) antimicrobial system or with iodine (I
2
). The oxidation of cell sulfhydryls and the iodination of cell components were measured. Both the peroxidase system and I
2
oxidized sulfhydryls. When the I
−
concentration in the peroxidase system was greater than 100 μM, the peroxidase system and I
2
were equivalent. That is, sulfhydryl oxidation or killing per mole of H
2
O
2
equaled that per mole of I
2
. These results were consistent with peroxidase-catalyzed oxidation of I
−
to yield 1 mol of I
2
per mol of H
2
O
2
. Sulfhydryls were oxidized to yield sulfenic acids and free I
−
. With I
−
concentrations in the range of 10 to 100 μM, the amount of sulfhydryls oxidized by the peroxidase system could exceed the amount of I
−
. Because the oxidation of sulfhydryls to sulfenic acids did not consume I
−
, one I
−
ion could participate in the oxidation of many sulfhydryls. With I
−
concentrations lower than 10 μM, complete oxidation of sulfhydryls was not obtained. Incorporation of I
−
into iodinated derivatives of bacterial components partly depleted the system of I
−
and limited the formation of I
2
. These results indicated that antimicrobial activity was due to peroxidase-catalyzed oxidation of I
−
to I
2
, followed by I
2
oxidation of cell components. There was a direct relationship between sulfhydryl oxidation and antimicrobial action. Although iodination of bacterial components accompanied sulfhydryl oxidation, the amount of I
−
incorporation was not directly related to antimicrobial action. Also, incorporation of I
−
interfered with antimicrobial action at low I
−
concentrations.
在培养大肠杆菌后,研究了细菌成分的化学修饰。
大肠杆菌
与过氧化物酶-过氧化氢(H
2
O
2
)-碘化物(I
-
)抗菌系统或用碘(I
2
).测量了细胞巯基的氧化和细胞成分的碘化。过氧化物酶系统和 I
2
都氧化了巯基。当 I
-
浓度大于 100 μM 时,过氧化物酶系统和 I
2
是等效的。也就是说,每摩尔 H
2
O
2
相当于每摩尔 I
2
.这些结果与过氧化物酶催化的 I
-
生成 1 摩尔 I
2
每摩尔 H
2
O
2
.巯基被氧化后生成亚硫酸和游离的 I
-
.与 I
-
浓度在 10 到 100 μM 之间时,过氧化物酶系统氧化的巯基数量可能超过 I
-
.由于将巯基氧化成亚硫酸不会消耗 I
-
因此,一个 I
-
离子可以参与许多巯基的氧化。用 I
-
浓度低于 10 μM 时,巯基不能被完全氧化。I
-
与细菌成分的碘化衍生物结合,部分消耗了系统中的 I
-
并限制了 I
2
.这些结果表明,抗菌活性是由于过氧化物酶催化 I - 的氧化作用而产生的。
-
氧化成 I
2
氧化成 I
2
氧化细胞成分。巯基氧化与抗菌作用之间存在直接关系。虽然细菌成分的碘化伴随着巯基氧化,但 I
-
掺入量与抗菌作用没有直接关系。此外,I
-
的掺入干扰了抗菌作用。
-
浓度时,I