Photophysics and photochemistry of horseradish peroxidase A2 upon ultraviolet illumination.

ABSTRACT: Detailed analysis of the effects of ultraviolet (UV) and blue light illumination of horseradish peroxidase A2, a heme-containing enzyme that reduces H(2)O(2) to oxidize organic and inorganic compounds, is presented. The effects of increasing illumination time on the protein's enzymatic activity, Reinheitzahl value, fluorescence emission, fluorescence lifetime distribution, fluorescence mean lifetime, and heme absorption are reported. UV illumination leads to an exponential decay of the enzyme activity followed by changes in heme group absorption. Longer UV illumination time leads to lower T(m) values as well as helical content loss. Prolonged UV illumination and heme irradiation at 403 nm has a pronounced effect on the fluorescence quantum yield correlated with changes in the prosthetic gr

SUBMITTER: Neves-Petersen MT 

PROVIDER: S-EPMC1861803 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature