UV light absorption

UV light absorption refers to the physical process where molecules, particularly proteins and nucleic acids, capture ultraviolet radiation through π-electron transitions in chromophores like aromatic amino acids (tyrosine, phenylalanine) and nucleotide bases (adenine, thymine). Proteins peak at 280 nm, nucleic acids at 260 nm, enabling quantification in spectroscopy but also driving biological effects such as DNA photoproducts (e.g., pyrimidine dimers) from UVB absorption, which impair replication and trigger repair or apoptosis. UVA absorption by molecules like NADH or porphyrins generates reactive oxygen species (ROS), contributing to oxidative stress, while UVB photoisomerizes trans-urocanic acid to immunosuppressive cis-UCA and stimulates cutaneous neuroendocrine responses independent of vitamin D. These processes link to disease via acute sunburn inflammation (mRNA damage via ZAK-alpha), chronic photoaging, and carcinogenesis, with systemic impacts on immune, endocrine, and brain functions like serotonin modulation. No drugs directly target "UV light absorption" as it is not a discrete molecular entity like a receptor or enzyme; instead, sunscreens block UV to prevent chromophore excitation.

Other names

UV absorptionultraviolet absorptionUV spectrophotometry