Partial purification and preliminary characterization of pyruvate kinase from the brown alga<i>Ascophyllum nodosum</i>

Davison, I. R.

doi:10.1080/00071618700650461

Cited by 7 publications

(1 citation statement)

References 35 publications

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“…(1981) who showed that the protein content of the crude extract declined with the increase in centrifugation speed. Elution profiles of phaeophycean proteins from ion-exchange resins have in the past been poor (Marsden et al 1981, Davison 1987. Pharmacia DEAE-Sephadex A-25 (Rice and Crowden 1987) may be useful because it removes much of the carbohydrate, but it is particularly poor for the separation of proteins and is not to be recommended for this task (Mike Dyson, Pharmacia, pers.…”

Section: Discussionmentioning

confidence: 99%

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹

Johnston

Raven

1989

Journal of Phycology

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Phosphoenolpyruvate carboxykinase (PEPCK) from Ascophyllum nodosum (L.) Le Jolis was partially purified and characterized to investigate its role in inorganic carbon assimilation in macroalgae. Inorganic carbon isotopic disequilibrium studies showed that the carboxylation of phosphoenolpyruvate utilized CO2 rather than HCO3−as its source of inorganic carbon. This is consistent with the enzyme being a phosphoenolpyruvate carboxykinase rather than a phosphoenolpyruvate carboxylase. Pre‐incubation with Mn2+alone activated PEPCK more effectively than when combinations of Mn2+, ADP and HCO3−were used as activators. Activation of PEPCK during catalysis was found not to occur. Although the activation of PEPCK reduced the Km for CO2 by a factor of 2.25, the value reported here of 1.084 mM CO2 for the activated enzyme at pH 7.0 is at the top of the range of previously reported values for brown algal PEPCK. The specific activity of PEPCK was increased from 0.268 μmol·min−1·mg−1in the crude extract to 33.03 μmol·min−1·mg−1in the partially purified preparations. Whether PEPCK can act as an initial carboxylating enzyme is discussed. Triton X‐100 at 0.57% (v/v) was found to be the optimum detergent and concentration for the extraction of enzymes from A. nodosum. When high concentrations of detergents ‐were used, a low (NH4)2SO4 cut was required to remove the free detergent from solution, which was extracted by centrifugation. Q Sepharose was used to partially purify PEPCK and separate it from pyruvate kinase. Good protein separations were consistently obtained.

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Section: Discussionmentioning

confidence: 99%

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹

Johnston

Raven

1989

Journal of Phycology

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Temperature acclimation of respiration and photosynthesis in the brown algaLaminaria saccharina

1991

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Abstract. Sporophytes of the brown alga Laminaria saccharina (L.) Lamour grown at 15°C contained significantly more chlorophyll a (chl a) than did similar plants grown at 5°C. The increase in chl a in 15°C plants was due to increased numbers of photosystem II reaction centes, and possibly to increased photosynthetic unit size, compared with 5 °C plants. These changes were associated with increased e values (photosynthetic efficiencies) in 15 °C-grown L. saccharina relative to 5 °C-grown plants. The changes in e together with reduced respiration rates allowed 15 °C-grown L. saccharina to achieve net photosynthesis and light-saturated photosynthesis at a lower photon fluence rate (PFR) than 5 °C plants when both groups were assayed at the same temperature (15 °C). The photon fluence rates necessary to reach the compensation point and achieve light-saturated photosynthesis (I c and Ik, respectively) increased with increasing incubation temperature in L. saccharina grown at both 5 and 15 °C. However, acclimation responses to growth temperature compensated for the short-term effect of temperature on I c and I k. Consequently, plants grown at 5 and 15 °C were able to achieve similar rates of light-limited photosynthesis, and similar I c and I k values at their respective growth temperatures. These responses are undoubtedly important for perennial seaweeds such as L. saccharina, which frequently grow in light-limited habitats and experience pronounced seasonal changes in water temperature.

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The role of pyruvate hub enzymes in supplying carbon precursors for fatty acid synthesis in photosynthetic microalgae

2015

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Photosynthetic microalgae are currently the focus of basic and applied research due to an ever-growing interest in renewable energy resources. This review discusses the role of carbon-unit supply for the production of acetyl-CoA, a direct precursor of fatty acid biosynthesis and the primary building block of the growing acyl chains for the purpose of triacylglycerol (TAG) production in photosynthetic microalgae under stressful conditions. It underscores the importance of intraplastidic acetyl-CoA generation for storage lipid accumulation. The main focus is placed on two enzymatic steps linking the central carbon metabolism and fatty acid synthesis, namely the reactions catalyzed by the plastidic isoform of pyruvate kinase and the chloroplastic pyruvate dehydrogenase complex. Alternative routes for plastidic acetyl-CoA synthesis are also reviewed. A separate section is devoted to recent advances in functional genomics studies related to fatty acid and TAG biosynthesis.

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Partial purification and preliminary characterization of pyruvate kinase from the brown algaAscophyllum nodosum

Cited by 7 publications

References 35 publications

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹

Temperature acclimation of respiration and photosynthesis in the brown algaLaminaria saccharina

The role of pyruvate hub enzymes in supplying carbon precursors for fatty acid synthesis in photosynthetic microalgae

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Partial purification and preliminary characterization of pyruvate kinase from the brown algaAscophyllum nodosum

Cited by 7 publications

References 35 publications

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)1

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)1

Temperature acclimation of respiration and photosynthesis in the brown algaLaminaria saccharina

The role of pyruvate hub enzymes in supplying carbon precursors for fatty acid synthesis in photosynthetic microalgae

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Product

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EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹

EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)¹