Properties of the Ultraviolet‐light‐mediated Binding of Bovine Serum Albumin to Dna*

The binding of DNA to protein mediated by U V (254 nm) radiation has been investigated using binding of the complex to Millipore membrane filters as an assay technique. The reaction proceeds through an activated protein intermediate which then reacts with the DNA. The activated protein has a half‐life of about 75 min at 0°C and about 18 min at 37°C. Short wavelengths are more efficient in forming the complex than wavelengths in the 250–280 nm range. N‐ethyl maleimide treatment of protein before irradiation markedly inhibits the reaction.