+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Magnetic circular dichroism study of cytochrome ba3 from Thermus thermophilus: Spectral contributions from cytochromes b and a-3 and nanosecond spectroscopy of carbon monoxide photodissociation intermediates

, : Magnetic circular dichroism study of cytochrome ba3 from Thermus thermophilus: Spectral contributions from cytochromes b and a-3 and nanosecond spectroscopy of carbon monoxide photodissociation intermediates. Biochemistry 31(39): 9376-9387

Near-UV-vis magnetic and natural circular dichroism (MCD and CD) spectra of oxidized reduced, and carbonmonoxy-complexed cytochrome ba-3, a terminal oxidase from the bacterium Thermus thermophilus, and nanosecond time-resolved MCD (TRMCD) and CD (TRCD) spectra of the unligated species formed after photodissociation of the CO complex are presented. The spectral contributions of individual cytochromes b and a-3 to the Soret region MCD are identified. TRMCD spectroscopy is used to follow the spin state change (S = 0 to S = 2) in cytochrome a-3-2+ following photodissociation of the CO complex. There is prompt appearance of the high-spin state after photolysis, as found previously in mammalian cytochrome oxidase (Goldbeck, R. A., Dawes, T. D., Einarsdottir, O., Woodruff, W. H., and Kliger, D. S. (1991) Biophys. J. 60, 125-134). Peak shifts of 1-10 nm appear in the TRMCD, TRCD, and time-resolved UV-vis absorption spectra of the photolyzed enzyme throughout its observable lifetime, indicating that the photolyzed enzyme does not relax to its equilibrium deliganded form before recombination with CO occurs hundreds of milliseconds later. Direct heme-heme interaction is not found in cytochrome ba-3 but red-shifts in the MCD and absorption spectra of both cytochromes b and (photolyzed) a-3 are correlated with a CO-liganded form of the protein. The long time (tau gtorsim 1 s) needed for relaxation of the cytochrome b and a-3 peaks to their static positions suggests that CO binding to a-3 induces a global conformational change in the protein that weakly perturbs the MCD and absorption spectra of b and photolyzed a-3. Fe-a-3 binds CO more weakly in cytochrome ba-3 than in cytochrome aa-3. The MCD spectrum of reduced enzyme solution placed under 1 atm of CO contains a peak at 446 nm that shows apprx 30% of total cytochrome a-3 remains pentacoordinate, high-spin.


DOI: 10.1021/bi00154a008

Other references

Warabi, T., 1977: The reaction time of eye head coordination in man. The reaction time of eye-head coordination was studied in man in connection with different target angles. The reaction time of the electromyographic activity in neck and of saccadic eye movement increased with increase of visual target angles. The...

Bergamini, T.M.; CorpusRoberto A.Jr.; Brittian, K.R.; Peyton, J.C.; Cheadle, W.G., 1994: The natural history of bacterial biofilm graft infection. A mouse model was developed to study the natural history of vascular prosthetic graft infection due to Staphylococcus epidermidis. Graft infections were established in the back subcutaneous tissue of 46 mice by implantation of Dacron prostheses co...

Nutman, A.P.; Friend, C.R.L., 2010: New 120,000 scale geological maps and synthesis of the Isua supracrustal belt and adjacent orthogneisses, southern West Greenland; a window into the Eoarchaean. Geological Society of Australia 98: 327-328

Uvnäs, B.; Aborg, C.H., 1984: Cation exchange--a common mechanism in the storage and release of biogenic amines stored in granules (vesicles)? II. Comparative studies on sodium-induced release of biogenic amines from the synthetic weak cation-exchangers Amberlite IRC-50 and duolite CS-100 and from biogenic (granule-enriched) materials. Superfusion of phenylethylamine-, noradrenaline- or histamine-charged weak (carboxyl) cation-exchangers (IRC-50 and Duolite CS-100) with isotonic NaCl caused a release of the amines. Similarly, bovine chromaffin granules and nerve granule preparat...

Borras, T.; Tamm, E.; Zigler, J.S.Jr, 1996: Efficiency and toxicity of gene delivery to the anterior segment of rabbits. Investigative Ophthalmology & Visual Science 37(3): S10

Tobola S., 1969: Electro myographic examination of the lower limb muscles in athlete weight lifters. Acta Physiologica Polonica (English Translation) TT(69-50009-5): 652-657

Young, E.A.; Harris, M.M.; Cantu, T.L.; Alcock, N.; Sandstead, H.H., 1993: Heart mineral and protein response to very low energy diet and refeeding. FASEB Journal 7(3-4): A388

Imsland, A.K.; Foss, A.; Stefansson, S.O.; Mayer, I.; Norberg, B.; Roth, B.; Jenssen, M.D., 2006: Growth, feed conversion efficiency and growth heterogeneity in Atlantic halibut (Hippoglossus hippoglossus) reared at three different photoperiods. Juvenile Atlantic halibut, Hippoglossus hippoglossus (initial weight (SD) 191.3 ([plus or minus]44.7)) g, were reared for 99 days at a constant temperature of 11[degree]C and subjected to three different light regimes from 13 September to 21 Decem...

Soltan, A.; Romer, W.; Schilling, G., 1991: Comparison of various soil extraction methods for the characterization of phosphate supply in Egyptian and German soils. Ten procedures were used to extract phosphate from 39 Egyptian soils taken from the Delta, NW coastal region and Sinai peninsula; the results were compared with uptake by rye plants. Correlations between extracted and taken-up phosphate were highe...

Künzel, W., 1986: Dentistry at the threshold of the 21st century. Stomatologie der Ddr 36(5): 253-255