CO-reacting haemoproteins of neutrophils: Evidence for cytochrome b-245 and myeloperoxidase as potential oxidases during the respiratory burst

1987 ◽  
Vol 7 (3) ◽  
pp. 193-199 ◽  
Author(s):  
Steven W. Edwards ◽  
David Lloyd
Keyword(s):  
Cytochrome B ◽  
Respiratory Burst ◽  
Absorption Maximum ◽  
Room Temperature ◽  
Polymorphonuclear Leucocytes ◽  
O2 Uptake ◽  
Difference Spectra ◽  
Action Spectra ◽  
Photochemical Action

Room temperature, CO-difference spectra of intact rat polymorphonuclear leucocytes (neutrophils) revealed the presence of a number of CO-binding haemoproteins. Absorption maxima at 413, 540 and 570 nm were attributed to the CO-complex of cytochrome b-245 whereas an absorption maximum at 595 nm was assigned to the contribution from a myeloperoxidase complex, since an identical absorption maximum was observed in CO-difference spectra of purified myeloperoxidase in the presence of H2O2. Photochemical action spectra for the relief of CO-inhibited O2 uptake revealed contributions from both cytochrome b-245 and myeloperoxidase. The potential of these two O2- and CO-binding haemoproteins to function as oxidases during the respiratory burst is discussed.

scholarly journals Photochemical action spectra indicate that cytochrome a/a3 is the predominant haemoprotein terminal oxidase in Acanthamoeba castellanii

1983 ◽  
Vol 210 (3) ◽  
pp. 721-725 ◽  
Author(s):  
R I Scott ◽  
D Lloyd
Keyword(s):  
Cytochrome B ◽  
Room Temperature ◽  
Stationary Phases ◽  
Acanthamoeba Castellanii ◽  
Terminal Oxidase ◽  
Difference Spectra ◽  
Intact Cells ◽  
Action Spectra ◽  
Stages Of Growth ◽  
Photochemical Action

1. Room-temperature CO-reduced minus reduced difference spectra of intact cells of Acanthamoeba castellanii show the presence of CO-reacting haemoproteins in cells from the early-exponential, late-exponential and stationary phases of growth. 2. The relative rates of reaction with CO of the two haemoproteins differ; that of cytochrome a/a3 with CO is complete within 1 min of bubbling with CO, whereas that of cytochrome b takes longer than 90 min. 3. Photochemical action spectra reveal cytochrome a/a3 as the predominant haemoprotein oxidase at all stages of growth. 4. It is concluded that the alternative oxidases known to be present in these organisms are not cytochromes.

scholarly journals Multiple light-induced reactions of cytochromes b and c in Rhodopseudomonas spheroides

1969 ◽  
Vol 114 (4) ◽  
pp. 793-799 ◽  
Author(s):  
O. T. G. Jones
Keyword(s):  
Cytochrome C ◽  
Cytochrome B ◽  
Photochemical Reaction ◽  
Room Temperature ◽  
Close Association ◽  
Antimycin A ◽  
Reaction Centre ◽  
Difference Spectra ◽  
Cytochromes C ◽  
Rhodopseudomonas Spheroides

Illumination of chromatophore preparations from Rhodopseudomonas spheroides causes the oxidation of a cytochrome c and a slight oxidation of a cytochrome b with a maximum at 560nm. When illuminated in the presence of antimycin A the oxidation of cytochrome c was more pronounced and cytochrome b560 was reduced; the dark oxidation of cytochrome b560 was biphasic in the presence of succinate, but not in the presence of NADH, a less effective reductant. Split-beam spectroscopy showed that, in addition to the reduction of cytochrome b560, another pigment with maxima at 565 and 537nm. was reduced and was more rapidly oxidized in the dark than cytochrome b560. This pigment, tentatively identified as cytochrome b565, was also detected in spectra at 77°k, after brief illumination at room temperature; the maxima at 77°k were at 562 and 536nm. In the absence of antimycin A, light caused a transient reduction of cytochrome b565 and an oxidation of cytochrome b560. Dark oxidation of b565 was rapid, even in the presence of antimycin A and succinate. Difference spectra, at 77°k, of ascorbate-reduced minus succinate-reduced chromatophores or of anaerobic succinate-reduced minus aerobic succinate-reduced chromatophores suggested that two cytochromes c were present, with maxima at 547 and 549nm. When chromatophores frozen at 77°k were illuminated both these cytochromes c were oxidized, indicating a close association with the photochemical reaction centre. A scheme involving two reaction centres is proposed to explain these results.

scholarly journals Haemoprotein terminal oxidases in the nematodes Nippostrongylus brasiliensis and Ascaridia galli

1988 ◽  
Vol 256 (1) ◽  
pp. 295-298 ◽  
Author(s):  
T A Paget ◽  
M Fry ◽  
D Lloyd
Keyword(s):  
Muscle Tissue ◽  
Endogenous Respiration ◽  
Nippostrongylus Brasiliensis ◽  
Reproductive Tissue ◽  
Ascaridia Galli ◽  
Difference Spectra ◽  
Cytochrome Aa3 ◽  
Action Spectra ◽  
Terminal Oxidases ◽  
Photochemical Action

1. Mitochondria isolated from the gut-dwelling nematodes Nippostrongylus brasiliensis and Ascaridia galli (muscle and gut + reproductive tissue) were examined for cytochromes, and it was observed that N. brasiliensis and A. galli muscle tissue mitochondria contained a-, b- and c-type cytochromes, but their stoichiometries were quite different (1:2:1.9 and 1:11.4:13.6 respectively); A. galli gut + reproductive-tissue mitochondria, however, only contained b and c cytochromes, in a ratio of 1:0.8. 2. CO difference spectra showed the presence of CO-reacting b-type cytochrome(s) in all three types of mitochondria; the fast-reacting species comprised 30, 44 and 39% of the total in N. brasiliensis, A. galli muscle and A. galli gut + reproductive-tissue mitochondria respectively. 3. Cytochrome aa3 was observed in N. brasiliensis mitochondria and in those from A. galli muscle, but was below the level of detectability (less than 0.005 nmol/mg of protein) for A. galli gut + reproductive-tissue mitochondria. 4. Photochemical action spectra for the reversal of CO inhibition of the endogenous respiration of whole worms (at 24 microM- and 40 microM-O2 respectively for N. brasiliensis and A. galli) gave maxima at 598 and 542-543 nm, corresponding to the alpha- and beta-absorption maxima of cytochrome aa3, and at 567 nm (b-type cytochrome) for both worms. These results suggest that cytochrome aa3 is the major functional oxidase in N. brasiliensis, whereas the CO-reacting b-type cytochrome dominates in A. galli.

scholarly journals The enzymic reduction and kinetics of oxidation of cytochrome b.245 of neutrophils

1982 ◽  
Vol 204 (2) ◽  
pp. 479-485 ◽  
Author(s):  
A R Cross ◽  
F K Higson ◽  
O T G Jones ◽  
A M Harper ◽  
A W Segal
Keyword(s):  
Plasma Membrane ◽  
Cytochrome B ◽  
Room Temperature ◽  
Human Neutrophils ◽  
Polymorphonuclear Leucocytes ◽  
Myristate Acetate ◽  
Kinetics Of Oxidation ◽  
Granule Fraction ◽  
Kinetics Of ◽  
Stimulation Of

1. The absorption coefficient of human neutrophil plasma-membrane reduced-minus-oxidized cytochrome b-245 was determined [delta epsilon (mM; 559-540 nm) = 21.6 cm-1]. 2. Neutrophil polymorphonuclear leucocytes (neutrophils) were prepared from human, ox, horse and pig blood. In each case plasma-membrane fractions were found to contain low-potential cytochrome b. When membranes from horse neutrophils were incubated anaerobically with either NADH or NADPH the cytochrome b became reduced. Prior stimulation of the cells with phorbol myristate acetate did not increase the rate or extent of cytochrome b reduction in isolated membranes, but did increase both the rate and extent of reduction by NADPH in Triton-treated cells. 3. A cytochrome b was present also in the specific granule fraction of human neutrophils. Its Em (pH 7.0) was found to be -248 mV, very similar to that of the plasma-membrane cytochrome b. 4. The rate of oxidation of reduce cytochrome b-245 by air-saturated buffer, was determined by using stopped-flow techniques. In intact membranes t 1/2 for oxidation was 4.7 ms. This rate is sufficiently rapid to support the view that cytochrome b-245 is the oxidase in the respiratory burst of neutrophils. 5. Plasma-membrane cytochrome b of human neutrophils formed a complex with CO. At room temperature and 1 atm of CO approx. 40% of the cytochrome formed a complex; approx. 60% binding was measured at the increased concentration of dissolved CO achieved at 5 degrees C. The concentration of CO giving 50% binding was 1.18 mM.

Oxidation of formate by mycobacteria of the Scrofulaceum group

1978 ◽  
Vol 24 (12) ◽  
pp. 1548-1552
Author(s):  
M. Ishaque ◽  
S. J. Kim ◽  
L. Kato
Keyword(s):  
Cytochrome B ◽  
Absorption Maximum ◽  
Redox State ◽  
Formate Dehydrogenase ◽  
Complete Oxidation ◽  
Difference Spectra ◽  
Intact Cells ◽  
Oxidase System ◽  
Formate Oxidation ◽  
A Value

Intact cells obtained from Mycobacterium scrofulaceum as well as from mycobacterial strains M.A6 and M.R56 isolated respectively from leprous tissues of armadillo and rat leproma and grown with glycerol as the oxidizable substrate catalyzed complete oxidation of formate. The stoichiometry of formate oxidase system yielded a value of 2 mol of CO2 produced per mole of O2 or per 2 moles of formate consumed. Cell-free preparations from these three strains of mycobacteria contained formate dehydrogenase which was associated exclusively in the particulate fraction. Formate oxidation was markedly stimulated by small amounts of selenite and molybdate added together. Formate-reduced minus oxidized difference spectra disclosed cytochromes of the b type while spectral evidence did not suggest the existence of cytochromes a or c components. The effect of 2-N-heptyl-4-hydroxyquinoline-N-oxide on the redox state of cytochromes indicated that formate oxidation was mediated by cytochrome b with absorption maximum of 556 nm and not of 562 nm.

Use of Near-Infrared–Mid-Infrared Dual-Wavelength Spectrometry to Obtain Two-Dimensional Difference Spectra of Sesame Oil as Inactive Drug Ingredient

2020 ◽  
pp. 000370282096919
Author(s):  
Masahiro Watari ◽  
Akifumi Nagamoto ◽  
Takuma Genkawa ◽  
Shigeaki Morita
Keyword(s):  
Room Temperature ◽  
Near Infrared ◽  
Sesame Oil ◽  
Partial Least Square ◽  
Dual Wavelength ◽  
Two Dimensional ◽  
Difference Spectra ◽  
Mid Infrared ◽  
Starting Point ◽  
Drug Ingredient

The present study has investigated the transformation of sesame oil kept at low temperature during a definite period of time for refinement (called winterization) as an inactive drug ingredient by using two-dimensional difference spectra (2D-DS) analysis of spectra collected using a near-infrared (NIR) and mid-infrared (MIR) dual-wavelength spectrometer (NIR–MIR-DWS). The NIR and MIR spectra were measured nearly simultaneously from samples of sesame oil before and after winterization. The difference spectrum analysis of the obtained NIR–MIR data elucidated that, after the winterization process, the absorbances at peaks attributed to C=O, C=C, and OH groups decrease while the absorbances arising from the main chain (CH2) increase. The result indicated the removal of lignan and the fatty acids with relatively short main chains. Moreover, sesame oil unwinterized was cooled from room temperature to near 1 ℃ and subsequently warmed to room temperature. And the cycle was repeated two times. Real-time monitoring during the cooling and warming processes were carried out using the NIR-MIR-DWS. The prediction results obtained from partial least square calibration model for the temperature suggests that there are subtle differences in the oil composition between the first cooling process and after the warming and cooling cycle. For the more detailed analysis, the 2D-DS method is proposed. The results of the analyses using 2D-DS revealed that the starting point of the transformation is around 15 ℃. It can be estimated that sesame oil is mainly transformed by the first cooling down. Moreover, it was implied that the structure of methylene (CH2) was significantly related to the modifications in sesame oil with temperature change. A series of experimental results elucidated that the winterization of sesame oil removed its impurities and stabilized its conditions. These results are probably the first report on the effect of the winterization process on sesame oil.

Oxidation–reduction titration of cytochrome components in the electron transport chain of Azotobacter vinelandii

1981 ◽  
Vol 59 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Tsanyen Yang
Keyword(s):  
Electron Transport ◽  
Cytochrome B ◽  
Absorption Maximum ◽  
Azotobacter Vinelandii ◽  
Reactive Component ◽  
Midpoint Potential ◽  
Oxidation Reduction ◽  
Membrane Bound ◽  
The Individual ◽  
Cytochrome D

The multiple cytochrome components in the electron transport particle of Azotobacter vinelandii were resolved and their oxidation–reduction midpoint potentials were determined by a simultaneous potentiometric and absorption measurements under anaerobic condition with or without CO. The midpoints of the individual cytochrome component corresponding to the membrane-bound types were also determined in the solubilized fractions prepared by a differential detergent solubilization of the membrane particles of A. vinelandii. Two cytochromes of b type, one with an absorption maximum measured at 559 nm and another at 561 nm in the membrane particle, were resolved and their Em, 7.4 values determined to be −30 mV and +122 mV, respectively. Cytochrome b559 reacted with CO readily in both membrane-bound and solubilized forms, however, cytochrome b561 was inert to CO treatment. Only one cytochrome of c type (c4) measured at 575–551 nm was resolved, its midpoint potential at pH 7.4 was +322 mV in the membrane-bound form and +278 mV in the solubilized form. This c-type cytochrome had no CO reactivity. Cytochrome d, a CO-reactive component, had a midpoint of +270 mV in the membrane fraction. The midpoint of cytochrome a1 in its membrane-bound form could not be measured accurately because of its low concentration. However, in the solubilized preparations, cytochrome a1 apparently had a red shift with an absorption maximum at 613 nm, with an estimated Em, 7.4 of −45 mV, while cytochrome d was no longer detected, possibly because of denaturation.

scholarly journals Carbon monoxide-reacting haemoproteins in the mitochondrial fraction of Acanthamoeba castellanii

1980 ◽  
Vol 186 (3) ◽  
pp. 669-678 ◽  
Author(s):  
S W Edwards ◽  
D Lloyd
Keyword(s):  
Carbon Monoxide ◽  
Low Temperature ◽  
Room Temperature ◽  
Acanthamoeba Castellanii ◽  
Mitochondrial Fraction ◽  
Submitochondrial Particles ◽  
Difference Spectra ◽  
Intact Cells ◽  
Mitochondrial Fractions ◽  
Eukaryotic Organisms

1. Room-temperature (18 degrees C) CO difference spectra of mitochondrial fractions from the amoeba Acanthamoeba castellanii reveal the presence of at least four CO-reacting haemoproteins. As well as cytochrome a3, other components reacting with CO are: (i) a c-type cytochrome; (ii) a b-type cytochrome; and (iii) another a-type cytochrome. 2. The same components can be identified in low-temperature photodissociation experiments with intact cells or mitochondria. 3. The time of exposure to CO and the nature of the reductant are both important in identifying all the components present, in that the b-type cytochrome is more readily distinguished after longer exposure to CO and more of the c-type cytochrome is detectable when NADH is the reductant 4. Treatment of mitochondria with ultrasound releases two components, identifiable in low-temperature difference spectra as a c-type and a b-type cytochrome; only the latter appears to have any reaction with CO, and the CO-reacting c-type cytochrome is retained in submitochondrial particles. 5. The complexity of the CO-reacting haemoproteins in this organism is compared with the simpler systems found in other eukaryotic organisms.

The action spectrum of hemoprotein oxidase in Nitrobacter agilis

1969 ◽  
Vol 47 (5) ◽  
pp. 507-509 ◽  
Author(s):  
Joan E. Hill ◽  
C P. S. Taylor
Keyword(s):  
Room Temperature ◽  
Action Spectrum ◽  
Terminal Oxidase ◽  
Height Ratio ◽  
Cytochrome O ◽  
Half Height ◽  
Nitrobacter Agilis ◽  
The Many ◽  
Half Height Width ◽  
Photochemical Action

A photochemical action spectrum for the relief by light of the carbon monoxide inhibition of respiration in Nitrobacter agilis (ATCC No. 14123) has been determined by the method of Castor and Chance, the first such determination in a chemolithotrophic organism. The cells were grown at 30 °C in liquid culture, were used when consuming 2–4 mM/ml per day of nitrite, and were concentrated by centrifuging. They respired actively at room temperature for about 3 h in air but only 75 min in the CO:O2 (4:1) mixture. Consistent γ and α bands of a hemoprotein spectrum were obtained from the combined results of two cultures. The maxima are at 432 ± 2 and 592 ± 2 nm; the γ/α height ratio is 6.4 (±22%) and the half-height width of the γ band is 15 nm. Since cytochrome a1 but not a3 has been reported in several Nitrobacter studies, the conclusion is that an a1-type cytochrome is a terminal oxidase in Nitrobacter agilis. The great scatter in the points around the β peak presumably results from the many cultures used, and possibly from differing oxidase activities in different phases of growth. The breadth of the peak could result from the presence of cytochrome o in some cultures. The possibility of more than one terminal oxidase is not excluded.

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