title: Photooxidation of soybean apoleghemoglobin with protoporphyrin IX, heme and dye.
abstract: Soybean apoleghemoglobin a was irradiated with visible light in the presence of different sensitizers to probe the heme environment of the protein. With protoporphyrin IX as sensitizer, specific photooxidation of histidine-92 and histidine-61 occurred. Irradiation of oxyleghemoglobin and cyanleghemoglobin resulted in photooxidation of histidine-92, while addition of methylene blue caused both histidine-92 and histidine-61 to be oxidized. Apoleghemoglobin, irradiated in the presence of rose bengal or methylene blue, lost tryptophan-128 in addition to the two histidines.
mesh_terms: D001059:Apoproteins; D006418:Heme; D006420:Hemeproteins; D007874:Leghemoglobin; D008027:Light; D008751:Methylene Blue; D010084:Oxidation-Reduction; D010777:Photochemistry; D011166:Porphyrins; D011524:Protoporphyrins; D012395:Rose Bengal; D013025:Glycine max
chemical_list: D001059:Apoproteins; D006420:Hemeproteins; D007874:Leghemoglobin; D011166:Porphyrins; D011524:Protoporphyrins; D012395:Rose Bengal; D006418:Heme; D008751:Methylene Blue