Purification and Partial Characterization of Microsomal NADH-Cytochrome b5 Reductase from Higher Plant Catharanthus roseus

Madyastha, K. M.; Chary, N.K.; Holla, Raveendra; Karegowdar, T.B.

doi:10.1006/bbrc.1993.2509

Cited by 6 publications

(3 citation statements)

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“…Several biochemical features of NFR are also in common with those of animal b 5 R. These include molecular mass [22], FAD content, sequential reaction mechanism, specificity for NADH, activity with Fe(III)‐chelates, and inhibition by PHMB [26]. Far less is known about b 5 Rs of plants [24, 27], but the few data available, including those referring to a PHMB‐sensitive juglone reductase of 31 kDa purified from onion roots plasma membrane [28], are again fully consistent with a strict relationship to NFR.…”

Section: Discussionmentioning

confidence: 93%

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase

et al. 1997

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Section: Discussionmentioning

confidence: 93%

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase

et al. 1997

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“…Most of these features are in common with NADH: cytochrome b 5 reductases (Bagnaresi and Pupillo 1995) and we additionally show that NADH preincubation of NFCHR prevents PHMB-inactivation as for cytochrome b 5 reductase (Table 4). Cytochrome b 5 reductases, however, (including a preparation from Cataranthus roseus cells, Madyastha et al 1993) are reported to be unable to reduce cytochrome c in the absence of cytochrome b 5 , in contrast to NFCHR. Cytochrome b 5 reductase is a component of the microsomal fatty acid desaturase complex (Ozols et al 1984), but a similar protein participates in methe-moglobin (Fe 3+ -Hb) reduction in human red blood cells (Yubisui and Takeshita 1982;Borgese et al 1993).…”

Section: Discussionmentioning

confidence: 99%

The NADH-dependent Fe 3+ -chelate reductases of tomato roots

Bagnaresi

Basso²,

Pupillo

1997

Planta

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The NADH-dependent Fe(3+)-chelate reductase (NFCHR) of tomato (Lycopersicon esculentum L.) roots, a strategy I species, was investigated. The Fe(3+)-citrate reductase (FeCitR) assay was strongly inhibited by p-hydroxymercuribenzoic acid (PHMB); moreover, the inhibitor was found to be more specific to the FeCitR assay than to the Fe(3+)-EDTA reductase assay, which was catalyzed by at least another reductase of 46 kDa. After high-speed centrifugation of tomato root membranes, high FeCitR activities were detected in pellets and lower activities in supernatants. After two-phase partitioning of microsomes, FeCitR activity (91 nmol.min-1.mg-1) was less active in the upper phase (plasma membrane) than in the lower phase (277 nmol.min-1.mg-1). However, only the activity of the plasma-membrane-associated NFCHR (FeCitR) was significantly enhanced (2.6-fold) in iron-deficient tomato plants, whereas that of NFCHR in non-plasma-membrane rich fractions was unaffected by this treatment. The NFCHR obtained from lysophosphatidylcholine-solubilized plasma membrane was present as a 200-kDa protein complex following fast protein liquid chromatography on Superdex 200, or as a 28-kDa form following Blue Sepharose CL-6B chromatography. Both preparations were more active following iron starvation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the 28-kDa protein purified from solubilized tomato microsomes or supernatant fractions by a final Mono Q step consisted of a single band of 32 kDa. Tomato root NFCHR resembled the NFCHR of maize (a strategy II plant, P Bagnaresi and P Pupillo, 1995, J Exp Bot 46: 1497-1503) in several properties: relative molecular mass, hydrophilicity, chromatographic behaviour, sensitivity to mercurials, specificity for electron donors and acceptors (e.g. cytochrome c), and a ferricyanide reductase-to-FeCitR ratio of 2.5. Preincubation with NADH partially protected NFCHR from PHMB-induced inactivation. Our data show that strategy I and II plants seem to share similar NFCHR proteins, which appear to belong to the cytochrome b5 reductase flavoprotein group.

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“…Investigations carried out on artichoke (Cynara scolymus) indicate the existence of several forms of reductase. Other data indicate the functioning of di!erent forms of this enzyme in plants (Madyastha et al, 1993). In animal organisms only one molecular form of reductase has been found; in plant microsomes there are at least three functional forms.…”

Section: Components Of Monooxygenase Systemmentioning

confidence: 98%

Organic Toxicants and Plants

Körte¹,

Kvesitadze²,

Ugrekhelidze³

et al. 2000

Ecotoxicology and Environmental Safety

119

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Purification and Partial Characterization of Microsomal NADH-Cytochrome b5 Reductase from Higher Plant Catharanthus roseus

Cited by 6 publications

References 0 publications

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase

The NADH-dependent Fe 3+ -chelate reductases of tomato roots

Organic Toxicants and Plants

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Purification and Partial Characterization of Microsomal NADH-Cytochrome b5 Reductase from Higher Plant Catharanthus roseus

Cited by 6 publications

References 0 publications

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b5 reductase

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b5 reductase

The NADH-dependent Fe 3+ -chelate reductases of tomato roots

Organic Toxicants and Plants

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Resources

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NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase

NADH:Fe(III)‐chelate reductase of maize roots is an active cytochrome b₅ reductase