RT Journal Article SR Electronic(1) A1 Poole, R. K. A1 Van Wielink, J. E. A1 Baines, B. S. A1 Reijnders, W. N. M. A1 Salmon, I. A1 Oltmann, L. F.YR 1983 T1 The Membrane-bound Cytochromes of an Aerobically Grown, Extremely Thermophilic Bacterium, PS3: Characterization by Spectral Deconvolution Coupled with Potentiometric Analysis JF Microbiology, VO 129 IS 7 SP 2163 OP 2173 DO https://doi.org/10.1099/00221287-129-7-2163 PB Microbiology Society, SN 1465-2080, AB Cytochromes of the a, b and c types in membranes from the thermophilic bacterium PS3 have been characterized with respect to their spectral, potentiometric and ligand-binding properties. The integrated approach used (a) conventional potentiometric analysis with non-linear least-square analysis, (b) incorporation of the potentiometric procedures into a spectral decomposition protocol at 298 and 77 K, (c) fourth-order finite difference and fourth derivative analysis, and (d) photodissociation studies of the CO-liganded components. Either one c-type cytochrome with a split α-band (547, 552 nm at 77 K) or two cytochromes c with similar redox potentials (approx. +230 mV) were found, together with at least three b-type cytochromes (554, 557 and 561 nm at 77 K). On the basis of its high redox potential (+104mV), cytochrome b 557 was tentatively equated with the o-type oxidase of this organism. A c-type cytochrome that formed a photodissociable complex with CO was also detected. The α-band of the previously purified cytochrome c oxidase was resolved into two components, having spectral and potentiometric properties remarkably similar to those of the analogous mitochondrial oxidase., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-129-7-2163