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 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.

Cytochemical localization of cytochrome oxidase in tissues of parasitic nematodes

Parasitology ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 145-156 ◽  
Author(s):  
M. Fry ◽  
J. E. Beesley
Keyword(s):  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Parasitic Nematodes ◽  
Nippostrongylus Brasiliensis ◽  
Reproductive Tissue ◽  
Ascaridia Galli ◽  
Transport Pathway ◽  
Cytochemical Staining ◽  
Cytochemical Localization ◽  
Cytochrome Oxidase Activity

Cytochemical staining with diaminobenzidine (DAB) has been used to locate cytochrome oxidase activity in mitochondria from major tissues of three intestinal parasitic nematodes, Nippostrongylus brasiliensis, Haemonchus contortus and Ascaridia galli. Deposition of DAB reaction product was uniform and relatively intense in mitochondria from all tissues studied in N. brasiliensis. However, mitochondria from different tissues of H. contortus and A. galli varied considerably in their cytochemical staining, decreasing in the order hypodermis < muscle < gut < reproductive tissue. Mitochondria in gut and reproductive tissue of A. galli possessed little or no cytochrome oxidase activity. These results are compatible with respect to oxygen availability and the extent and localization of the mammalian-type aerobic mitochondrial electron transport pathway in intestinal parasitic nematodes.

scholarly journals The O2-dependence of respiration and H2O2 production in the parasitic nematode Ascaridia galli

1988 ◽  
Vol 256 (2) ◽  
pp. 633-639 ◽  
Author(s):  
T A Paget ◽  
M Fry ◽  
D Lloyd
Keyword(s):  
Electron Transport ◽  
Muscle Tissue ◽  
Parasitic Nematode ◽  
H2o2 Production ◽  
Reproductive Tissue ◽  
Ascaridia Galli ◽  
Transport Pathway ◽  
Transport Pathways ◽  
Transport Chain ◽  
Carbonyl Cyanide

1. Respiration in the parasitic nematode worm Ascaridia galli was inhibited at O2 concentrations in excess of 255 microM, and an apparent Km,O2 of 174 microM was determined. 2. Mitochondria-enriched fractions isolated from the tissues of A. galli have much lower apparent Km,O2 values (approx. 5 microM). They produce H2O2 in the energized state; higher rates of H2O2 production were observed in the presence of the uncoupler carbonyl cyanide m-chlorophenylhydrazone. 3. Antimycin A inhibited respiration in muscle tissue mitochondria by 10%, but had no effect on respiration in gut + reproductive tissue mitochondria; the major portion of respiration in both types of mitochondria could be attributed to an alternative electron-transport pathway. 4. o-Hydroxydiphenyl, an inhibitor of alternative electron-transport pathways, inhibits respiration by 98% and completely inhibits the production of H2O2 in gut-plus-reproductive-tissue mitochondria; respiration and H2O2 production in muscle tissue mitochondria were inhibited by 90 and 86% respectively. 5. Another inhibitor of alternative electron transport, salicylhydroxamic acid, had the same effect as o-hydroxydiphenyl on H2O2 production and respiration in gut-plus-reproductive-tissue mitochondria. However, its effect on muscle tissue mitochondria was complex; a low concentration (0.35 mM) stimulated H2O2 production, whereas 3 mM inhibited respiration by 87% and prevented H2O2 production completely. 6. The similarities between the apparent Km,O2 values for H2O2 production and respiration in muscle mitochondria and in gut-plus-reproductive-tissue mitochondria suggests that the site of H2O2 production on the alternative electron-transport chain is cytochrome ‘o’. 7. These results are discussed in relation to potential O2 toxicity in A. galli.

scholarly journals Cytochrome a620 in Tetrahymena pyriformis. Reactions with carbon monoxide and oxygen at subzero temperatures and photochemical action spectra

1982 ◽  
Vol 206 (2) ◽  
pp. 367-372 ◽  
Author(s):  
D Lloyd ◽  
R I Scott ◽  
S W Edwards ◽  
C Edwards ◽  
B Chance
Keyword(s):  
Electron Transport ◽  
Tetrahymena Pyriformis ◽  
Terminal Oxidase ◽  
Ciliate Protozoan ◽  
Whole Cells ◽  
Action Spectra ◽  
Terminal Oxidases ◽  
Subzero Temperatures ◽  
Electron Transport Chains ◽  
Photochemical Action

1. Mitochondria-enriched fractions of the ciliate protozoan Tetrahymena pyriformis ST contained CO-reacting cytochromes b560 and a620. 2. A non-photodissociable oxygen-containing compound of cytochrome a620 was formed in whole cell suspensions at −114 degrees C after photolysis of CO in the presence of 200 microM-O2. 3. Electron transport, indicated by the oxidation of cytochrome a620 and cytochrome c, occurred at temperatures higher than −72 degrees C. 4. Photochemical action spectra for the relief of respiratory inhibition of whole cells by CO obtained by using a liquid dye laser indicate that the only CO-reacting terminal oxidase detectable was cytochrome a620. 5. It is concluded that the alternative electron transport chains in this organism utilize non-cytochrome terminal oxidases.

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 The oxidation of nicotinic acid by Pseudomonas ovalis Chester. The terminal oxidase

1972 ◽  
Vol 129 (3) ◽  
pp. 755-761 ◽  
Author(s):  
M. V. Jones ◽  
D. E. Hughes
Keyword(s):  
Electron Transport ◽  
Nicotinic Acid ◽  
Electron Transport Chain ◽  
Acid Oxidase ◽  
Terminal Oxidase ◽  
Difference Spectra ◽  
Terminal Oxidases ◽  
Cytochrome O ◽  
Transport Chain ◽  
Terminal Oxidation

In cell-free extracts of Pseudomonas ovalis nicotinic acid oxidase is confined to the wallmembrane fraction. It is associated with an electron-transport chain comprising b- and c-type cytochromes only, differing proportions of which are reduced by nicotinate and NADH. CO difference-spectra show two CO-binding pigments, cytochrome o (absorption maximum at 417nm) and another component absorbing maximally at 425nm. Cytochrome o is not reduced by NADH or by succinate but is by nicotinate, which can also reduce the ‘425’ CO-binding pigment. The effects of inhibitors of terminal oxidation support the idea of two terminal oxidases and a scheme involving the ‘425’ CO-binding pigment and the other components of the electron-transport chain is proposed.

Dye-induced fluorescence of tumour cells: photochemical action spectra

1974 ◽  
Vol 6 (3) ◽  
pp. 237-243 ◽  
Author(s):  
A. L. Bastos ◽  
D. Marques ◽  
M. A. Affra
Keyword(s):  
Tumour Cells ◽  
Action Spectra ◽  
Photochemical Action
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