697 DEAE-Toyopearl 27.1 105 3.88 Q-Sepharose 21.1 30.8 1.46 Hydroxyapatite 2.00 15.1 7.55 Spectroscopic properties of cytochromes in A. pernix Selleck GDC0449 The redox difference spectrum of membranes showed α-band peaks with maxima

at 554 and 610 nm (Figure 2a), derived from c – and a -type cytochromes, respectively. The isolated cytochrome c 553 in the reduced state showed an absorption peak at 553 nm (Figure 2b, dotted line). The pyridine ferro-hemochrome spectrum showed 2 α-band peaks with maxima at 551 and 557 nm, indicating the presence of heme C and heme B (Figure 2b, solid line) [18]. The redox spectrum of the cytochrome oa 3 oxidase showed α-band peaks with maxima at 555 and 610 nm (Figure 2c, dotted line) and the pyridine ferro-hemochrome spectrum did α-band peaks with maxima at 553 and 588 nm (Figure 2c, solid line), indicating the presence of heme O and heme A [18, 19]. To determine the heme species of the oxidase in more detail, total heme was extracted from the partially purified oxidase preparation and analyzed by mass spectrometry. We observed 3 peaks at VX-689 mw molecular masses of 630.44, 888.94, and 920.98 (Figure 3). The molecular mass of 888.94 matches that

of heme Op1, which was identified in Sulfolobus and other species [20], while the see more molecular mass of 920.98 matches that of heme As. The molecular mass of 630.44 matches that of heme B, which is probably contamination from other cytochromes, because the peak height is lower than those of hemes Op1 and As, and this oxidase does not contain b -type heme (Figure 2c). The difference spectrum of the CO-bound, reduced form minus Casein kinase 1 the reduced form showed a peak and a trough at 595 nm and 611 nm, respectively, in the α region (Figure 2d) and those at 432 nm and 444 nm in the γ region (data not shown), indicating that CO was bound to an a -type heme (Figure 2d), and thus the oxidase was designated a cytochrome oa 3-type. Figure 2 Spectra of cytochromes in A. pernix. Difference spectrum in the sodium dithionite-reduced form minus the air-oxidized

form (dotted line) and pyridine ferro-hemochromes (solid line) of membranes (a), cytochrome c 553 (b), and cytochrome oa 3 oxidase (c). To measure a spectrum of membranes, they were solubilized with 5% (w/v) Triton X-100, as described in Materials and Methods. Difference spectrum of the CO-reduced minus the reduced forms of cytochrome oa 3 oxidase (d). The partially purified oxidase was reduced with sodium dithionite (baseline) and then bubbled with CO gas for 1 min. Figure 3 Heme analysis by MALDI-TOF mass spectrometry of partially purified cytochrome oa 3 oxidase from A. pernix. Heme was extracted from the oxidase preparation by shaking vigorously with acetone-HCl, followed by extraction with ethyl acetate. The extracted heme was analyzed by MALDI-TOF mass spectrometry as detailed in the “”Materials and Methods”".