Abstract
When a total soluble extract of Nitrosomonas europaea was denatured with dodecyl sulphate, subjected to dodecyl sulphate/polyacrylamide-gel electrophoresis and illuminated with near-u.v. light, eight bands of protein fluorescence were observed. All but one of these bands were red in colour, a property characteristic of c-type cytochromes. Standard techniques were used to purify soluble c-type cytochromes from this organism, and it was then possible to assign all but two very minor bands to specific c-type cytochromes, namely hydroxylamine oxidase, cytochrome c-554, cytochrome c-552 and a cytochrome c-550 not previously described. The eight band had fluorescence peaking in the green region of the spectrum, probably caused by covalently bound flavin, and co-purified with hydroxylamine oxidase. The following physical properties were determined for these components: isoelectric point, molecular weights according to gel filtration and mobility on dodecyl sulphate/polyacrylamide gels, and α-band spectra at room temperature and 77K. Redox potentials were measured as follows: cytochrome c-554, Em,7 = +20mV; cytochrome c-552, Em,7 = +230mV; cytochrome c-550, Em,7 = +140mV. When washed membranes were applied to dodecyl sulphate/polyacrylamide gels in the same way, a number of fluorescent bands were observed that could be matched by soluble proteins. In addition, there was one band that could not be detected in supernatants, migrating with an apparent molecular weight of 24000. This species is probably coincident with a c-type cytochrome having Em,7 = +170mV found in redox titration of these membranes. In future studies, gel fluorescence should form a useful complement to spectroscopy for analysis of cytochrome composition in active cell-free preparations or semi-purified material.
Full text
PDF






Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andrews P. The gel-filtration behaviour of proteins related to their molecular weights over a wide range. Biochem J. 1965 Sep;96(3):595–606. doi: 10.1042/bj0960595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutton P. L. Redox potentiometry: determination of midpoint potentials of oxidation-reduction components of biological electron-transfer systems. Methods Enzymol. 1978;54:411–435. doi: 10.1016/s0076-6879(78)54026-3. [DOI] [PubMed] [Google Scholar]
- ESTABROOK R. W. The low temperature spectra of hemoproteins. I. Apparatus and its application to a study of cytochrome c. J Biol Chem. 1956 Dec;223(2):781–794. [PubMed] [Google Scholar]
- HOFMAN T., LEES H. The biochemistry of the nitrifying organisms. IV. The respiration and intermediary metabolism of Nitrosomonas. Biochem J. 1953 Jul;54(4):579–583. doi: 10.1042/bj0540579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hooper A. B., Maxwell P. C., Terry K. R. Hydroxylamine oxidoreductase from Nitrosomonas: absorption spectra and content of heme and metal. Biochemistry. 1978 Jul 25;17(15):2984–2989. doi: 10.1021/bi00608a007. [DOI] [PubMed] [Google Scholar]
- Katan M. B. Detection of cytochromes on sodium dodecylsulphate-polyacrylamide gels by their intrinsic fluorescence. Anal Biochem. 1976 Jul;74(1):132–137. doi: 10.1016/0003-2697(76)90316-x. [DOI] [PubMed] [Google Scholar]
- Suzuki I., Kwok S. C. A partial resolution and reconstitution of the ammonia-oxidizing system of Nitrosomonas europaea: role of cytochrome c554. Can J Biochem. 1981 Jul;59(7):484–488. doi: 10.1139/o81-067. [DOI] [PubMed] [Google Scholar]
- Terry K. R., Hooper A. B. Hydroxylamine oxidoreductase: a 20-heme, 200 000 molecular weight cytochrome c with unusual denaturation properties which forms a 63 000 molecular weight monomer after heme removal. Biochemistry. 1981 Nov 24;20(24):7026–7032. doi: 10.1021/bi00527a039. [DOI] [PubMed] [Google Scholar]
- Tronson D. A., Ritchie G. A., Nicholas D. J. Purification of c-type cytochromes from Nitrosomonas europaea. Biochim Biophys Acta. 1973 Jun 15;310(2):331–343. doi: 10.1016/0005-2795(73)90113-x. [DOI] [PubMed] [Google Scholar]
- Weber K., Pringle J. R., Osborn M. Measurement of molecular weights by electrophoresis on SDS-acrylamide gel. Methods Enzymol. 1972;26:3–27. doi: 10.1016/s0076-6879(72)26003-7. [DOI] [PubMed] [Google Scholar]
- Wood P. M. Do photosynthetic bacteria contain cytochrome c1? Biochem J. 1980 Sep 1;189(3):385–391. doi: 10.1042/bj1890385. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yamanaka T., Shinra M. Cytochrome c-552 and cytochrome c-554 derived from Nitrosomonas europaea. Purification, properties, and their function in hydroxylamine oxidation. J Biochem. 1974 Jun;75(6):1265–1273. doi: 10.1093/oxfordjournals.jbchem.a130510. [DOI] [PubMed] [Google Scholar]
- Yamanaka T., Shinra M., Takahashi K., Shibasaka M. Highly purified hydroxylamine oxidoreductase derived from Nitrosomonas europaea. Some physicochemical and enzymatic properties. J Biochem. 1979 Oct;86(4):1101–1108. doi: 10.1093/oxfordjournals.jbchem.a132604. [DOI] [PubMed] [Google Scholar]
