%0 Journal Article %A Miller David, J. %A Wood Paul, M. %A Nicholas, D.J.D. %T Further Characterization of Cytochrome P-460 in Nitrosomonas europaea %D 1984 %J Microbiology, %V 130 %N 11 %P 3049-3054 %@ 1465-2080 %R https://doi.org/10.1099/00221287-130-11-3049 %I Microbiology Society, %X Reduction of cells or extracts of Nitrosomonas europaea with dithionite leads to a peak in absorption spectra at 460 nm. Most of this chromophore is bound to hydroxylamine oxidase, but a small fraction exists as a separate protein, namely cytochrome P-460. An improved purification of both these proteins is described. The mobility of cytochrome P-460 on gel electrophoresis in the presence of SDS corresponded to a molecular weight of 18000, whereas a molecular weight of 52000 was determined by gel filtration. The band obtained by electrophoresis gave a yellow-green fluorescence in UV light. Electrophoresis in the presence of 8 m-urea, or after acid-treatment, resulted in red fluorescence from cytochrome P-460. We previously reported that extracts from N. europaea gave eight fluorescence bands in SDS-polyacrylamide gels; cytochrome P-460 was found to correspond to the previously unassigned band VI. Electrophoresis of purified hydroxylamine oxidase did not give a band in common with cytochrome P-460. Highly purified cytochrome P-460 gave no detectable flavin-type fluorescence. There was no antigenic similarity between hydroxylamine oxidase and cytochrome P-460. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-130-11-3049