Carboxylation of pyruvate and acetyl coenzyme A by reversal of the sodium pumps oxaloacetate decarboxylase and methylmalonyl-CoA decarboxylase

Dimroth, Peter; Hilpert, Wilhelm

doi:10.1021/bi00317a039

Cited by 47 publications

(29 citation statements)

References 20 publications

(36 reference statements)

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“…The previously observed carboxylation of the substrate analogue acetyl-CoA to malonyl-CoA on application of an electrochemical gradient of Na' ions [14] indicates that all steps of the reaction cycle shown in Fig. 5 are reversible.…”

Section: Discussionmentioning

confidence: 67%

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On the mechanism of sodium ion translocation by methylmalonyl‐CoA decarboxylase from Veillonella alcalescens

Hilpert

Dimroth

1991

European Journal of Biochemistry

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Veillonella alcalescens during lactate degradation developed an Na+ concentration gradient with 7–8 times higher external than internal Na+ concentrations in the logarithmic growth phase. The gradient declined to a factor of 1.9 in the late stationary phase. Methylmalonyl‐CoA decarboxylase reconstituted into proteoliposomes performed an active electrogenic Na+ transport, creating Ψ of 60 mV, pNa+ of 50 mV, and of 110 mV. In the initial phase of the transport, the decarboxylase catalyzed the uptake of 2 Na+ ions/malonyl‐CoA molecule decarboxylated. During further development of the electrochemical Na+ gradient, this ratio gradually declined to zero, when decarboxylation continued without further increase of the internal Na+ concentration. The rate of malonyl‐CoA decarboxylation declined initially during development of the membrane potential, but remained unchanged later on. Monensin abolished the Na+ gradient and increased the malonyl‐CoA decarboxylation rate 2.8‐fold. On dissipating the membrane potential with valinomycin, the internal Na+ concentration reached three times higher values than in its absence, and the decarboxylation rate increased 2.8‐fold. Methylmalonyl‐CoA decarboxylase catalyzed an exchange of internal and external Na+ ions in addition to net Na+ accumulation. The initial rate of Na+ influx was double that of malonyl‐CoA decarboxylation. In the following, both rates decreased about twofold in parallel to values which remained constant during further development of the electrochemical Na+ gradient. Thus, Na+ influx and malonyl‐CoA decarboxylation follow a stoichiometry of approximately 2:1, independent of the magnitude of the electrochemical Na+ gradient and are thus highly coupled events.

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Section: Discussionmentioning

confidence: 67%

“…Especially tight vesicles were obtained by the detergent dialysis method and with K. pneumoniue lipids [14]. The proteoliposomes obtained after dialysis for 2-3 days were centrifuged and resuspended in 30 mM potassium phosphate pH 7.0 containing 1 mM Na2S04 and 0.5 mM dithioerythritol.…”

Section: Reconstitution Of Methylmalonyl-cod Decarboxylase Performingmentioning

confidence: 99%

On the mechanism of sodium ion translocation by methylmalonyl‐CoA decarboxylase from Veillonella alcalescens

Hilpert

Dimroth

1991

European Journal of Biochemistry

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“…Interestingly, PC has an intrinsic OAD activity because of its ability to stabilize a pyruvate enolate intermediate (32). Similarly, OAD is able to catalyze pyruvate carboxylation in vitro under certain conditions (33). The common features of Oad-␣/␥Ј and PC and the reversibility of the catalyzed reactions are indicative of a similar quaternary structure organization, and, therefore, PC might serve as a useful system to get insights into OAD structure and mechanism.…”

Section: Discussionmentioning

confidence: 99%

Quaternary Structure of the Oxaloacetate Decarboxylase Membrane Complex and Mechanistic Relationships to Pyruvate Carboxylases

Balsera

Buey

2011

Journal of Biological Chemistry

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“…This free energy is converted into an electrochemical gradient of Na + ions by methylmalonyl-CoA decarboxylase. which at an experimentally determined ratio of 2 mol Na+/mol methylmalonyl-CoA [28] could, at maximum, generate a djiNa+ of -120 mV. From these values and a conventional phosphorylation potential for growing bacterial cells of about -43 kJ/mol (-450 mV) [29], it can be calculated that the H + (Na' )/ATP stoichiometry must be at least 4.…”

Section: Discussionmentioning

confidence: 99%

The electrochemical proton potential ofBacillus alcalophilus

Hoffmann

Dimroth

1991

European Journal of Biochemistry

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Bricillus alt~alophili~r strain ATCC 27647 showed usual growth characteristics, when inoculated at pH 10.4. The cells entered the logarithmic phase at pH 10.3, and as growth continued, the pH dropped further to a value of 8.8 in the stationary phase. B. alcalophilus strain DSM 485 showed comparable growth only in the initial phase after the addition to fresh medium. The small initial growth period was succeeded by a long lag phase, where the pH continuously dropped. The cells resumed growth after the pH was about 10.0 and continued to grow accompanied by a further decrease of external pH. The bioenergetic parameters measured in the initial growth phase of the two strains at high pH (10.1 -10.3) were nearly the same, i.e. ApH = + 97 to + 110 mV, d y i = -206 to -213 mV and ADH+ = -109 to -103 mV. The inverted proton gradient of about 1.7-1.9 at high pH decreased, as the external pH dropped during growth. This led to an increase of the proton motivc force ( A D H + ) , although the membrane potential ( d~i ) also declined. The ATP/ADP ratio of strain DSM 485 was high (4.5 -5.5) at fast growth during the initial and second growth period. The ratio declined to about 1.5 at the end of the lag phase. At the initial growth phase and at the end of the lag phase, the ADH + was, however, the same ( z -106 mV) and considerably lower than in the middle of the second growth period ( z -140 mV). Fast growth, therefore. correlates with a high ATP/ADP ratio but not necessarily with a high ADH + . Addition of graniicidin or carbonylcyanide m-chlorophenylhydrazone stopped growth of B. alcrrlophilus strain DSM 485 at pH 10.3 or 9.5 and graniicidin immediately decreased the internal ATP/ADP ratio from 4.5 to 1.2 at pH 10.3.The obligate alkaliphilic bacteria grow at pH values above 10.0. At high alkaline pH values, the cytoplasmic pH is maintained at or below pH 8.6 by virtue of the electrogenic Na + / H + antiporter which is energized by A y established in the H ' -translocating respiratory chain [I]. The bioenergetic consequences of the antiporter action are a decrease of the proton motive force and a simultaneous increase of the sodium motive force. I t is reasonable, therefore, that the alkaliphilic bacteria use ADNa+ instead ofdfi,, to drive solute uptake [2] and flagellar motion [3]. Based on these data and on the notion that ATP synthesis in Propiotiigmium riiodestuni is driven by A b N a + [4], it was hypothesized by us and others that the alkaliphilic Bacilli likewise take advantage of the Na' -coupled ATP synthesis mechanism [5, 61.In order to test this hypothesis. we have recently isolated the ATPase of B~i l l i i s tiltdophilus [7]. Surprisingly, the purified enzyme, which is of the usual FIFO structure, catalyzed H t but not Na' translocation, if incorporated into proteoliposonies [8]. In addition, the reconstituted enzyme C'orres~Joriclc./ic.e to 1' . Dimroth. Mikrobiologisches Institut der ETH Ziirich. ETH-Zentrum, Schmclzbcrgstr. 7, CH-8092 Ziirich, SwitzerlandAhhrevicitiom. CCCP, carbonylcyanide rwchlorophenylhydra...

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Carboxylation of pyruvate and acetyl coenzyme A by reversal of the sodium pumps oxaloacetate decarboxylase and methylmalonyl-CoA decarboxylase

Cited by 47 publications

References 20 publications

On the mechanism of sodium ion translocation by methylmalonyl‐CoA decarboxylase from Veillonella alcalescens

On the mechanism of sodium ion translocation by methylmalonyl‐CoA decarboxylase from Veillonella alcalescens

Quaternary Structure of the Oxaloacetate Decarboxylase Membrane Complex and Mechanistic Relationships to Pyruvate Carboxylases

The electrochemical proton potential ofBacillus alcalophilus

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