Pulsed EPR studies of peroxide-activated cytochrome c peroxidase and of the mercaptoethanol derivative of Neurospora tyrosinase.
نویسندگان
چکیده
We have measured the linear electric field effect for peroxide-activated yeast cytochrome c peroxidase and for the mercaptoethanol derivative of Neurospora tyrosinase. Although both of these materials have EPR spectra resembling those of free radicals, the linear electric field effect measurements demonstrate that there is a metal ion associated with the paramagnetic centers. In addition, we have also observed superhyperfine interactions with 14N nuclei.
منابع مشابه
Electron-nuclear double resonance of the hydrogen peroxide compound of cytochrome c peroxidase: identification of the free radical site with a methionyl cluster.
The results of electron-nuclear double resonance and electron paramagnetic resonance (EPR) studies on the hydrogen peroxide compound of yeast cytochrome c peroxidase are inconsistent with previous proposals for the source of the EPR signal in this compound, in particular with its identification with an aromatic amino acid radical such as would arise by oxidation of a tryptophanyl side chain. Th...
متن کاملElectron paramagnetic and electron nuclear double resonance of the hydrogen peroxide compound of cytochrome c peroxidase.
We have collected electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) spectra from the hydrogen peroxide compound of yeast cytochrome c peroxidase, termed ES, employing EPR microwave frequencies of 9.6 and 11.6 GHz. We have measured and analyzed the temperature dependence of the spin-lattice relaxation rate (1/T1) of the paramagnetic center of ES over the tempera...
متن کاملIn vitro and in silico studies of the inhibitory effects of some novel kojic acid derivatives on tyrosinase enzyme
Objective(s): Tyrosinase is a key enzyme in pigment synthesis. Overproduction of melanin in parts of the skin results in hyperpigmentation diseases. This enzyme is also responsible for the enzymatic browning in fruits and vegetables. Thus, its inhibitors are of great importance in the medical, cosmetic and agricultural fields. Materials and Methods: A series of twelve kojic acid derivatives wer...
متن کاملStudies on Cytochrome c Peroxidase
Apoproteins of cytochrome c peroxidase, horseradish peroxidase, and sperm whale myoglobin were recombined with manganese complexes of proto-, hemato-, meso-, and deuteroporphyrins to form manganese porphyrin-protein complexes. These complexes were purified by column chromatography. All the manganese porphyrin-containing cytochrome c peroxidases were crystallized. Light absorption maxima of mang...
متن کاملThe reaction of hydrogen peroxide with the dimethyl ester heme derivative of cytochrome c peroxidase.
A modified cytochrome c peroxidase was prepared by reconstituting apocytochrome c peroxidase with protoheme in which both heme propionic acid groups were converted to the methyl ester derivatives. The modified enzyme reacted with hydrogen peroxide with a rate constant of (1.3 +/- 0.2) x 10(7) M-1 s-1, which is 28% that of the native enzyme. The reaction between the modified enzyme and hydrogen ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of biological chemistry
دوره 256 19 شماره
صفحات -
تاریخ انتشار 1981