UVA-irradiated pheomelanin alters the structure of catalase and decreases its activity in human skin.
More than 40 years ago Aronoff showed that catalase structure and activity is seriously affected by photo-oxidation of its own substrate, hydrogen peroxide, owing to cleavage of its porphyrin active site. Here we support the results of Maresca et al. and expand on them by using structural modeling of native catalase and its photo-oxidation product, where both methionine and tryptophan residues are oxidized, yielding a deactivated enzyme.
Wood
John M
JM
Clinical and Experimental Dermatology/Department of Biomedical Sciences, University of Bradford, Bradford, UK. J.M.Wood@bradford.ac.uk
Schallreuter
Karin U
KU
D002374:Catalase / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008543:Melanins / Q000528:radiation effects*; D008715:Methionine / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation / Q000528:radiation effects; D012867:Skin / Q000201:enzymology*; D014364:Tryptophan / Q000378:metabolism; D014466:Ultraviolet Rays
D008543:Melanins; C018362:pheomelanin; D014364:Tryptophan; D008715:Methionine; D002374:Catalase