Detection of Carbonylated Proteins Induced by Long-Wavelength UV and Blue Light Irradiation Using Keratin Film

Abstract

Light irradiation causes the generation of reactive oxygen and induces protein modifications such as carbonylation. This protein modification is employed as a marker of oxidation stress. Human hair keratin film has been known to be an effective device to measure the formation of carbonylated proteins caused by UV irradiation in daily life. When the keratin film was exposed by long-wavelength UVA (L-UVA) high energy visible light (HEV) (380-530 nm) irradiation, the formation of carbonylated proteins could be confirmed and the relative amount was about 40% compared with that by a solar simulator (300-2500 nm). This value was higher than expected and could not be ignored. Addition of UV absorbers such as benzophenone-3 and methoxydibenzoyl-methane revealed the inhibitory effects on the carbonyl formation by the solar simulator. However, the inhibitory effect was low or disappeared in the case that the keratin film was exposed to L-UVA-HEV irradiation. Among the visible lights, monochromatic blue light/HEV (400-500 nm) irradiation significantly caused the formation of carbonylated proteins compared with those by green light (500-550 nm) and red light (600-700 nm) irradiations. Thus, the keratin film will be a highly sensitive and convenient biomaterial to detect carbonyl formation by blue light/HEV as well as UV irradiation.