title: Unusual hyperporphyrin spectrum by bis(glutathione dimethyl ester)-hemin complex, a model of cytochrome P-450-thiolate complexes.
abstract: A bis(thiolato) complex of iron-porphyrin exhibiting a "split Soret band" with peaks at 374 and 466 nm, classified as a "hyperporphyrin (HP) spectrum", was prepared with Fe(III)protoporphyrin dimethyl ester (FePPIXDME), glutathione dimethyl ester (GSHDME) and tetrabutylammonium hydroxide in acetone solvent. The structure of the complex was characterized by comparing their electronic absorption and electron spin resonance (ESR) spectra with those of thiolate adducts of cytochrome P-450 and their chemical model complexes. Under the same conditions as those for the formation of the HP spectrum, the generation of the free superoxide anions was detectable by ESR spectrometry at 77K. On the basis of the results, the possible reaction mechanism generating the superoxide anions by the bis(GSHDME)-FePPIXDME complex was proposed.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Tokushima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sakurai
authors.forename: K
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: N
authors.initials: N
authors.lastname: Sugasaki
authors.forename: M
authors.initials: M
authors.lastname: Shibuya
mesh_terms: D000818:Animals; D002417:Cattle; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D005978:Glutathione / Q000031:analogs & derivatives* / Q000032:analysis; D006418:Heme / Q000031:analogs & derivatives*; D006427:Hemin / Q000032:analysis*; D011166:Porphyrins / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013481:Superoxides / Q000378:metabolism
chemical_list: D005609:Free Radicals; D011166:Porphyrins; D013438:Sulfhydryl Compounds; C064452:bis(glutathione dimethyl ester)-hemin complex; D013481:Superoxides; D006418:Heme; D006427:Hemin; D003577:Cytochrome P-450 Enzyme System; D005978:Glutathione