Superoxide dismutase and catalase in the protection of the proton-donating systems of nitrogen fixation in the blue-green alga <i>Anabaena cylindrica</i>

Henry, Landis E. A.; Гоготов, И. Н.; Hall, D.O.

doi:10.1042/bj1740373

Cited by 40 publications

(19 citation statements)

References 20 publications

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“…LB795 contained superoxide dismutase activity [2 to 9 units (mg protein)-l] at levels similar to those reported in extracts of Anabaena cylindrica (Henry et al, 1978). However, the catalase activity of the Gloeocapsa sp.…”

Section: Inhibition Of Nitrogen Fixation By Methyl Viologenmentioning

confidence: 86%

The Effects of Methyl Viologen on Gloeocapsa sp. LB795 and Their Relationship to the Inhibition of Acetylene Reduction (Nitrogen Fixation) by Oxygen

Tözüm

Gallon

1979

Journal of General Microbiology

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Methyl viologen (10 ,UM) markedly inhibited acetylene reduction (nitrogen fixation) by old but not young cultures of Gloeocapsa sp. LB795, apparently by causing the alga to produce H202. H,02 inhibited acetylene reduction when added to cultures at concentrations greater than 10 ,UM. As catalase (EC 1.11.1.6) is not present in Gloeocapsa sp. LB795, H202 is probably removed by a non-enzymic reaction with ascorbate and also by an enzymecatalysed reaction with glutathione. Enzymes catalysing the decomposition of H,O, were most active in young cells which were therefore better able than old cells to metabolize H202 produced in the presence of methyl viologen. The maximum activities of these enzymes coincided with maximum nitrogenase activity during the growth of batch cultures, and may provide a protective mechanism for nitrogenase.

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Section: Inhibition Of Nitrogen Fixation By Methyl Viologenmentioning

confidence: 86%

The Effects of Methyl Viologen on Gloeocapsa sp. LB795 and Their Relationship to the Inhibition of Acetylene Reduction (Nitrogen Fixation) by Oxygen

Tözüm

Gallon

1979

Journal of General Microbiology

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“…FeSOD was localized in the cytosol and MnSOD in the thylakoids in three cyanobacterial species (42). Superoxide dismutase activity was also measured in vegetative cells and heterocysts of A. cylindrica, with heterocysts having lower levels of activity (43). Four genes of SOD, one coding for an FeSOD and three coding for MnSOD, were characterized in P. boryanum (44).…”

Section: Discussionmentioning

confidence: 99%

The Iron Superoxide Dismutase from the Filamentous Cyanobacterium Nostoc PCC 7120

Regelsberger

Laaha

Dietmann

et al. 2004

Journal of Biological Chemistry

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The nitrogen-fixing filamentous cyanobacterium Nostoc PCC 7120 (formerly named Anabaena PCC 7120) possesses two genes for superoxide dismutase, a unique membrane-associated manganese superoxide dismutase (MnSOD) and a soluble iron superoxide dismutase (FeSOD). A phylogenetic analysis of FeSODs shows that cyanobacterial enzymes form a well separated cluster with filamentous species found in one subcluster and unicellular species in the other. Activity staining, inhibition patterns, and immunogold labeling show that FeSOD is localized in the cytosol of vegetative cells and heterocysts (nitrogenase containing specialized cells formed during nitrogen-limiting conditions). The recombinant Nostoc FeSOD is a homodimeric, acidic enzyme exhibiting the characteristic iron peak at 350 nm in its ferric state, an almost 100% occupancy of iron per subunit, a specific activity using the ferricytochrome assay of (2040 ؎ 90) units mg ؊1 at pH 7.8, and a dissociation constant K d of the azide-FeSOD complex of 2.1 mM. Using stopped flow spectroscopy it was shown that the decay of superoxide in the presence of various FeSOD concentrations is first-order in enzyme concentration allowing the calculation of the catalytic rate constants, which increase with decreasing pH: 5.3 ؋ 10 9 M ؊1 s ؊1 (pH 7) to 4.8 ؋ 10 6 M ؊1 s ؊1 (pH 10). FeSOD and MnSOD complement each other to keep the superoxide level low in Nostoc PCC 7120, which is discussed with respect to the fact that Nostoc PCC 7120 exhibits oxygenic photosynthesis and oxygen-dependent respiration within a single prokaryotic cell and also has the ability to form differentiated cells under nitrogen-limiting conditions.

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“…Catalase, aldolase and phosphofructokinase were assayed as described earlier (10,18). For enzyme assays, crude extract of the heterocysts was prepared.…”

Section: Materials An[) Methodsmentioning

confidence: 99%

Effect of light quality on the acetylene reducing activity of the isolated heterocysts of Anabaena sp. strain CA.

Kumar

1989

J. Gen. Appl. Microbiol.

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Superoxide dismutase and catalase in the protection of the proton-donating systems of nitrogen fixation in the blue-green alga Anabaena cylindrica

Cited by 40 publications

References 20 publications

The Effects of Methyl Viologen on Gloeocapsa sp. LB795 and Their Relationship to the Inhibition of Acetylene Reduction (Nitrogen Fixation) by Oxygen

The Effects of Methyl Viologen on Gloeocapsa sp. LB795 and Their Relationship to the Inhibition of Acetylene Reduction (Nitrogen Fixation) by Oxygen

The Iron Superoxide Dismutase from the Filamentous Cyanobacterium Nostoc PCC 7120

Effect of light quality on the acetylene reducing activity of the isolated heterocysts of Anabaena sp. strain CA.

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