Purification and Characterization of Pyrophosphate: <scp>D</scp>-Fructose 6-Phosphate 1-Phosphotransferase from Rice Seedlings

Enomoto, Toshiki; Ohyama, Hideo; Kodama, Miyuki

doi:10.1271/bbb.56.251

Cited by 10 publications

(9 citation statements)

References 7 publications

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“…The most effective inhibitors (other than Pi and PPi) were MgADP and PEP; however, no activators other than Fru-2,6-P, were found. (Table I), a value similar to that reported for homogeneous PFPs from various plant sources (Botha et al, 1987;Kruger and Dennis, 1987;Mahajan and Singh, 1989;Moorhead and Plaxton, 1991;Enomoto et al, 1992;Nielsen, 1994). During the initial trials of enzyme purification, the a subunit of PFP was found to be susceptible to partial proteolysis (Fig.…”

Section: Effects Of Other Metabolitessupporting

confidence: 84%

“…Fru-2,6-P,, however, generally does not affect the response of other PFPs to pH Botha et al, 1986Botha et al, , 1987Stitt, 1990). Also, pH 6.8 is a somewhat more acidic pH optimum than that reported for other PFPs, which typically display pH optima from pH 7.2 to 7.8 in the forward direction Botha et al, 1986Botha et al, , 1987Botha and Small, 1987;Mahajan and Singh, 1989;Wong et al, 1990;Enomoto et al, 1992;Nielsen, 1994). By contrast, Fru-2,6-P2 exerted a less prominent effect on the pH optimum of the reverse activity (Fig.…”

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 96%

“…Anaerobiosis generally results in a 0.4-to 0.8-unit decrease in the cytosolic pH of plant cells (Dancer and ap Rees, 1989). It is interesting that the only report of a similar effect of Fru-2,6-P2 on PFP's pH optimum was for the purified enzyme from rice seedling (Enomoto et al, 1992). Fru-2,6-P, was found to shift the pH optimum of rice seedling PFP toward a more acidic value for both the forward (decreased from pH 8.1 to 7.5) and reverse reactions (decreased from pH 7.9 to 7.4).…”

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 99%

“…Fru-2,6-P, was found to shift the pH optimum of rice seedling PFP toward a more acidic value for both the forward (decreased from pH 8.1 to 7.5) and reverse reactions (decreased from pH 7.9 to 7.4). It has been suggested that rice seedling PFP may function during anoxia as a glycolytic bypass to PFK (Mertens et al, 1990;Mertens, 1991;Enomoto et al, 1992).…”

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 99%

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Purification and Characterization of Pyrophosphate-Dependent Phosphofructokinase from Phosphate-Starved Brassica nigra Suspension Cells

Theodorou

Plaxton

1996

Plant Physiology

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Previously, we reported that inorganic phosphate (Pi) deprivation of Brassica nigra suspension cells or seedlings leads to a progressive increase in the a$-subunit ratio of the inorganic pyrophosphate (PPibdependent phosphofructokinase (PFP) and that this coincides with a marked enhancement in the enzyme's activity and sensitivity to its allosteric activator, fructose-2,6-bisphosphate (Fru-2,6-P2). To further investigate the effect of Pi nutrition on B. nigra PFP, the enzyme was purified and characterized from Pi-starved B. nigra suspension cell cultures. Polyacrylamide gel electrophoresis, immunoblot, and gel-filtration analyses of the final preparation indicated that this enzyme exists as a heterooctamer of approximately 500 kD and is composed of a 1 :1 ratio of immunologically distinct a (66 kD) and p (60 kD) subunits. l h e enzyme's a subunit was susceptible to partiai proteolysis during purification, but this was prevented by the presence of chymostatin and leupeptin. In the presence and absence of 5 p~ Fru-2,6-P2, the forward activity of PFP displayed pH optima of pH 6.8 and 7.6, respectively. Maximal activation of the forward and reverse reactions by Fru-2,6-P2 occurred at pH 6.8. l h e potent inhibition of the forward activity by Pi (concentration of inhibitor producing 50% inhibition of enzyme activity [Iso] = 1.3 mM) was attributed to a marked Pi-dependent reduction in Fru-2,6-P2 binding. l h e reverse reaction was substrate-inhibited by Pi (Iso = 13 mM) and product-inhibited by PPi (I5,, = 0.9 mM). l h e kinetic data are consistent with the hypothesis that PFP may function to bypass the ATP-dependent PFP in Pi-starved B. nigra. The importance of the Pi nutritional status to the regulation and predicted physiological function of PFP is emphasized.PFP catalyzes the reversible phosphorylation of Fru-6-P to Fru-1,6-P,, using PPi as a phosphoryl donor in the glycolytic (forward) direction and Pi as a phosphoryl acceptor in the gluconeogenic (reverse) direction. Although the enzyme has been purified and characterized from a wide variety of plant sources, an incontrovertable physiological role for PFP has yet to emerge (Kombrink et al.,

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Section: Effects Of Other Metabolitessupporting

confidence: 84%

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 96%

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 99%

Section: Kinetic and Regulatory Propertiesmentioning

confidence: 99%

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Purification and Characterization of Pyrophosphate-Dependent Phosphofructokinase from Phosphate-Starved Brassica nigra Suspension Cells

Theodorou

Plaxton

1996

Plant Physiology

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“…In rice, anoxia induces an increase in SUC synthase (Ricard et al, 1991) as well as an increase in PPi:Fru-6-P l-phosphotransferase but not phosphofructokinase (Mertens et al, 1990). Since anoxia also induces an increase in Fru-2,6-bisphosphate (Mertens et al, 1990), which activates PPi: Fru-6-P 1-phosphotransferase in the glycolytic rather than the reverse direction (Enomoto et al, 1992), these effects of anoxia favor glycolytic pathways utilizing PPi over those consuming ATP. In corn, it has been noted that, although many glycolytic enzymes are induced by hypoxia, none of these are kinases (Bailey-Serres et al, 1988).…”

mentioning

confidence: 99%

Vacuolar H+-Translocating Pyrophosphatase Is Induced by Anoxia or Chilling in Seedlings of Rice

et al. 1995

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Many plants are subjected to temporary anoxia or hypoxia as a result of flooding, waterlogging, or ice encasement. Among crop plants, rice (Oryza sativa L.) is the most tolerant of anoxic conditions (Mocquot et al., 1981), and corn (Zea mays L.) is also moderately tolerant (Johnson et al., 1989). In seedlings of these species, a number of metabolic changes have been observed in response to hypoxia, and evidence has been presented that at least some of these responses are adaptive, i.e. they increase the ability of the plant to survive the stress (Johnson et al., 1989). In anoxic conditions, cessation of oxidative phosphorylation typically results in a marked decrease in ATP levels (Raymond et al., 1985). This can be alleviated in tolerant species by an increase in alcoholic, lactic, and other fermentation pathways (Kennedy et al., 1992; Menegus et al., 19931, and many of the proteins induced by hypoxia are enzymes of these glycolytic pathways (Bailey-Serres et al., 1988). Chilling likewise creates energy stress (Stewart and Guinn, 1969) due to mitochondrial dysfunction (Lyons and Raison, 1970), and like hypoxia chilling induces alcohol dehydrogenase in corn and rice seedlings (Christie et al., 1991). 1-514-398-5069. 1As an additional adaptation to energy stress, glycolytic enzyme reactions consuming ATP can be at least partially replaced by reactions utilizing PPi as an energy source. In rice, anoxia induces an increase in SUC synthase (Ricard et al., 1991) as well as an increase in PPi:Fru-6-P l-phosphotransferase but not phosphofructokinase (Mertens et al., 1990). Since anoxia also induces an increase in Fru-2,6-bisphosphate (Mertens et al., 1990), which activates PPi: Fru-6-P 1-phosphotransferase in the glycolytic rather than the reverse direction (Enomoto et al., 1992), these effects of anoxia favor glycolytic pathways utilizing PPi over those consuming ATP. In corn, it has been noted that, although many glycolytic enzymes are induced by hypoxia, none of these are kinases (Bailey-Serres et al., 1988). Cytosolic PPi levels seem to be independent of those of ATP (Dancer et al., 1990) and unaffected by anoxic stress (Dancer and ap Rees, 1989). Moreover, the cytoplasmic acidification that commonly results from anaerobic metabolism tends to increase the free energy of hydrolysis of PPi but has the opposite effect on the free energy of ATP hydrolysis (Davies et al., 1993). It appears therefore that PPi metabolism may play an important role in plant adaptation to anoxia.The V-PPase (Rea and Poole, 1993) represents another enzyme that might advantageously replace an ATP-consuming one (the V-ATPase) in anoxia or chilling stress. These parallel proton pumps are ubiquitous in the plant kingdom, although present in differing proportions in various tissues and species. The reaction stoichiometries of the two enzymes (Davies et al., 1992;Schmidt and Briskin, 1993) permit them to generate approximately equal proton gradients (Hedrich et al., 1989) across the vacuolar membrane, and calculations of free energy changes (Davie...

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Diphosphate-fructose-6-phosphate 1-phosphotransferase

Springer Handbook of Enzymes

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Purification and Characterization of Pyrophosphate: D-Fructose 6-Phosphate 1-Phosphotransferase from Rice Seedlings

Cited by 10 publications

References 7 publications

Purification and Characterization of Pyrophosphate-Dependent Phosphofructokinase from Phosphate-Starved Brassica nigra Suspension Cells

Purification and Characterization of Pyrophosphate-Dependent Phosphofructokinase from Phosphate-Starved Brassica nigra Suspension Cells

Vacuolar H+-Translocating Pyrophosphatase Is Induced by Anoxia or Chilling in Seedlings of Rice

Diphosphate-fructose-6-phosphate 1-phosphotransferase

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