BioScience Trends. 2008;2(2):85-93. (DOI: )

UVB-dependent generation of reactive oxygen species by catalase and IgG under UVB light: Inhibition by antioxidants and anti-inflammatory drugs.

Murakami M, Taniguchi M, Takama M, Cui JH, Oyanagui Y

Catalase, which can decompose H2O2, has recently been found to generate unspecified reactive oxygen species (ROS) as a result of ultraviolet B (UVB) irradiation. Many proteins, hemes, and iron compounds were first tested to determine that this ROS generation was unique to catalase and immunoglobulin G (IgG). An increase in absorbance at 502 nm due to 2',7'-dichlorofluorescein, the oxidized product of 2',7'-dichlorodihydrofluorecein diacetate as a result of UVB (310 nm) irradiation, was measured in order to estimate this ROS generation. Catalase and IgG generated a pronounced amount of ROS when irradiated with UVB. Another heme protein, cytochrome c, and heat-inactivated catalase had no such effect. ROS generation by catalase was at least 5 times more potent than that reported for IgG with UVB and without antigens. This catalasemediated ROS generation was largely temperaturedependent in the range of 25 to 42

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