Localization of cytochrome C oxidase and cytochrome C peroxidase in mitochondria of Hymenolepis diminuta (cestoda)

McKelvey, Jeffrey R.; Fioravanti, Carmen F.

doi:10.1016/0305-0491(86)90008-8

Cited by 6 publications

(4 citation statements)

References 19 publications

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“…Cyto c R was evaluated by following the reduction of cytochrome c at 550 nm as described by McKelvey and Fioravanti (1986). In addition to enzyme and 0.3 mg horse heart cytochrome c, the 1.0 ml assay volume contained the following in lmoles: NADH, 0.24; potassium cyanide, 0.1; and buffer, 100.…”

Section: Enzyme Assaysmentioning

confidence: 99%

NADH→NAD⁺Transhydrogenation in AdultAscaris suumMitochondria

Holowiecki

Fioravanti

2015

Journal of Parasitology

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Although lacking an NADPH→NAD(+) transhydrogenase system, the essentially energetically anaerobic mitochondria of the adult intestinal nematode Ascaris suum display an inner membrane-associated NADH→NAD(+) transhydrogenation reaction. This reaction is considered to be reflective of a mechanism(s) that acts in catalyzing a transmembrane translocation of reducing equivalents from NADH in the intermembrane space to matrix NAD(+), thereby forming matrix NADH that would serve in electron transport. Ascarid mitochondrial lipoamide dehydrogenase rather than an NADH→NAD(+) transhydrogenase system has been viewed as the predominant source of inner membrane-associated NADH→NAD(+) transhydrogenation activity. However, the present study made apparent yet another source of mitochondrial, inner membrane-associated NADH→NAD(+) activity in A. suum , viz., NADH dehydrogenase. This was made evident via comparisons of the A. suum mitochondrial NADH→NAD(+) transhydrogenation, NADH dehydrogenase, and lipoamide dehydrogenase activities in terms of pH effects, thermal labilities, the involvement of NADH dehydrogenase in the activities of mitochondrial, membrane-associated rotenone-insensitive and rotenone-sensitive NADH-dependent cytochrome c reductases, and mitochondrial membrane versus mitochondrial soluble localizations. Studies of the responses of the NADH→NAD(+) transhydrogenation, rotenone-insensitive and rotenone-sensitive cytochrome c reductases, and lipoamide dehydrogenase activities to inhibition by copper and cadmium lent additional support to the catalysis of an NADH→NAD(+) transhydrogenation activity by NADH dehydrogenase. Collectively, the data presented are consistent with an additional physiological catalysis of an NADH→NAD(+) transhydrogenation in A. suum mitochondria by an inner membrane NADH dehydrogenase component of the rotenone-sensitive cytochrome c reductase system, i.e., the NADH dehydrogenase component of the electron transport system. Comparisons of the A. suum data with those from other essentially anaerobic helminth parasites as well as free-living eukaryotic mitochondrial systems are noted.

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Section: Enzyme Assaysmentioning

confidence: 99%

NADH→NAD⁺Transhydrogenation in AdultAscaris suumMitochondria

Holowiecki

Fioravanti

2015

Journal of Parasitology

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“…Adult H. diminuta mitochondria display cytochrome c reducing and oxidizing activities, i.e. membrane-associated NAD(P)H- and succinate-dependent cytochrome c reductase, cytochrome c oxidase, and a cytochrome c peroxidase as assessed by exogenous oxidized or reduced cytochrome c utilization (Kim and Fioravanti, 1985; McKelvey and Fioravanti, 1986). Rotenone-sensitive NADH-dependent cytochrome c reductase and succinate-dependent cytochrome c reductase activities exhibit antimycin A sensitivity whereas cytochrome oxidase activity is inhibited by sodium azide and potassium cyanide.…”

Section: Energetic Metabolism Of Adult Hymenolepis Diminutamentioning

confidence: 99%

“…It is noteworthy, therefore, that adult H. diminuta lacks appreciable catalase, glutathione peroxidase or NAD(P)H peroxidase activities, but does display peroxide-forming superoxide dismutase activity (Paul and Barrett, 1980; Barrett and Beis, 1982). Although the subject of differing opinions, the occurrence and intramitochondrial localization of peroxidase activity (or peroxidase-like activity) in adult H. diminuta has been reported using histochemical and biochemical methods (Threadgold et al 1968; Lumsden et al 1969; Robinson and Bogitsh, 1976, 1978; Paul and Barrett, 1980; Kim and Fioravanti, 1985; McKelvey and Fioravanti, 1986). A mitochondrial membrane association for a H. diminuta cytochrome c peroxidase has been indicated (Threadgold et al 1968; Robinson and Bogitsh, 1976, 1978; Paul and Barrett, 1980), but Kim and Fioravanti (1985), using a biochemical assessment found that cytochrome c peroxidase activity is associated predominantly (95% of recovered activity) with the soluble mitochondrial fraction.…”

Section: Energetic Metabolism Of Adult Hymenolepis Diminutamentioning

confidence: 99%

“…A mitochondrial membrane association for a H. diminuta cytochrome c peroxidase has been indicated (Threadgold et al 1968; Robinson and Bogitsh, 1976, 1978; Paul and Barrett, 1980), but Kim and Fioravanti (1985), using a biochemical assessment found that cytochrome c peroxidase activity is associated predominantly (95% of recovered activity) with the soluble mitochondrial fraction. Indeed, an evaluation of the intramitochondrial localization of the cestode cytochrome c peroxidase indicated a 55% matrix and 32% intermembrane space distribution, respectively (McKelvey and Fioravanti, 1986). Given the potential for peroxide formation by H. diminuta mitochondria and the apparent lack of a number of common peroxide-utilizing systems in the cestode, the occurrence of mitochondrial cytochrome c peroxidase activity merits additional study.…”

Section: Energetic Metabolism Of Adult Hymenolepis Diminutamentioning

confidence: 99%

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Transhydrogenase and the anaerobic mitochondrial metabolism of adultHymenolepis diminuta

Fioravanti

Vandock

2009

Parasitology

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The adult cestode, Hymenolepis diminuta, is essentially anaerobic energetically. Carbohydrate dissimilation results in acetate, lactate and succinate accumulation with succinate being the major end product. Succinate accumulation results from the anaerobic, mitochondrial, 'malic' enzyme-dependent utilization of malate coupled to ATP generation via the electron transport-linked fumarate reductase. A lesser peroxide-forming oxidase is apparent, however, fumarate reduction to succinate predominates even in air. The H. diminuta matrix-localized 'malic' enzyme is NADP-specific whereas the inner membrane (IM)-associated electron transport system prefers NADH. This dilemma is circumvented by the mitochondrial, IM-associated NADPH-->NAD+ transhydrogenase in catalyzing hydride ion transfer from NADPH to NAD+ on the IM matrix surface. Hydride transfer is reversible and phospholipid-dependent. NADP+ reduction occurs as a non energy-linked and energy-linked reaction with the latter requiring electron transport NADH utilization or ATP hydrolysis. With NAD+ reduction, the cestode transhydrogenase also engages in concomitant proton translocation from the mitochondrial matrix to the intermembrane space and supports net ATP generation. Thus, the cestode NADPH-->NAD+ system can serve not only as a metabolic connector, but an additional anaerobic phosphorylation site. Although its function(s) is unknown, a separate IM-associated NADH--> NAD+ transhydrogenation, catalyzed by the lipoamide and NADH dehydrogenases, is noted.

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