Relationship between the F0F1-ATPase and the K+-transport system within the membrane of anaerobically grownEscherichia coli. N,N?-dicyclohexylcarbodiimide-sensitive ATPase activity in mutants with defects in K+-transport

Trchоunian, Armen; Vassilian, Anait

doi:10.1007/bf00762741

Cited by 46 publications

(34 citation statements)

References 34 publications

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“…2). In both cases: in K + -free mixture (concomitant K + was *0.02 mM [17]) and in the presence of 100 mM K + , Cu 2+ increased markedly (*1.5-1.6-fold) the level of SHgroups. Note the number of SH-groups was a little bit higher in the presence of K + than in the absence of K + (Fig.…”

Section: Resultsmentioning

confidence: 90%

“…Note these vesicles had a high level of the N,N 0 -dicyclohexylcarbodiimide (DCCD)-inhibited ATPase activity [17,19] as well as the hydrogenase activity [4,8,16].…”

Section: Bacterial Strains and Growth Membrane Vesiclesmentioning

confidence: 99%

“…Membrane vesicles were prepared as described previously by Adler and Rosen [18] and detailed by Trchounian and Vassilian [17] except buffers, where K + lacked. Note these vesicles had a high level of the N,N 0 -dicyclohexylcarbodiimide (DCCD)-inhibited ATPase activity [17,19] as well as the hydrogenase activity [4,8,16].…”

Section: Bacterial Strains and Growth Membrane Vesiclesmentioning

confidence: 99%

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Copper (II) Ions Affect Escherichia coli Membrane Vesicles’ SH-Groups and a Disulfide-Dithiol Interchange Between Membrane Proteins

Kirakosyan

Trchounian

Vardanyan

et al. 2008

Cell Biochem Biophys

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The SH-groups in Escherichia coli membrane vesicles, prepared from cells grown in fermentation conditions on glucose at slightly alkaline pH, have a role in the F0F1-ATPase operation. The changes in the number of these groups by ATP are observed under certain conditions. In this study, copper ions (Cu2+) in concentration of 0.1 mM were shown to increase the number of SH-groups in 1.5- to 1.6-fold independent from K+ ions, and the suppression of the increased level of SH-groups by ATP was determined for Cu2+ in the presence of K+. Moreover, the increase in the number of SH-groups by Cu2+ was absent as well as the inhibition in ATP-dependent increasing SH-groups number by Cu2+ lacked when vesicles were treated with N-ethylmaleimide (NEM), specific thiol-reagent. Such an effect was not observed with zinc (Zn2+), cobalt (Co2+), or Cu+ ions. The increased level of SH-groups was observed in the hycE or hyfR mutants with defects in hydrogenases 3 or 4, whereas the ATP-dependent increase in the number of these groups was determined in hycE not in hyfR mutants. Both changes in SH-groups number disappeared in the atp or hyc mutants deleted for the F0F1-ATPase or hydrogenase 3 (no activity of hydrogenase 4 was detected in the hyc mutant used). A direct effect of Cu2+ but not Cu+ on the F0F1-ATPase is suggested to lead to conformational changes or damaging consequences, increasing accessible SH-groups number and disturbing disulfide-dithiol interchange within a protein-protein complex, where this ATPase works with K+ uptake system or hydrogenase 4 (Hyd-4); breaks in disulfides are not ruled out.

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Section: Resultsmentioning

confidence: 90%

“…Note these vesicles had a high level of the N,N 0 -dicyclohexylcarbodiimide (DCCD)-inhibited ATPase activity [17,19] as well as the hydrogenase activity [4,8,16].…”

Section: Bacterial Strains and Growth Membrane Vesiclesmentioning

confidence: 99%

Section: Bacterial Strains and Growth Membrane Vesiclesmentioning

confidence: 99%

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Copper (II) Ions Affect Escherichia coli Membrane Vesicles’ SH-Groups and a Disulfide-Dithiol Interchange Between Membrane Proteins

Kirakosyan

Trchounian

Vardanyan

et al. 2008

Cell Biochem Biophys

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“…Note that without adding glucose changes in H + activity by bacteria were insignificant. ATPase assays were done by determination of liberation of inorganic phosphate (P i ) in the other medium (50 mM Tris-HCl buffer, pH 7.5, 0.4 mM MgSO 4 [22,25]) with or without 100 mM KCl added. The reaction was initiated by adding 3 mM ATP (Tris salt) to vesicles and terminated at a given time by addition of 5% trichloroacetic acid or 0.1% sodium dodecyl sulphate.…”

Section: Bacteria and Reagents Bacterial Growth And Assaysmentioning

confidence: 99%

Extremely High Frequency Electromagnetic Radiation Enforces Bacterial Effects of Inhibitors and Antibiotics

Tadevosyan

Kalantaryan

Trchоunian

2008

Cell Biochem Biophys

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The coherent electromagnetic radiation (EMR) of the frequency of 51.8 and 53 GHz with low intensity (the power flux density of 0.06 mW/cm(2)) affected the growth of Escherichia coli K12(lambda) under fermentation conditions: the lowering of the growth specific rate was considerably (approximately 2-fold) increased with exposure duration of 30-60 min; a significant decrease in the number of viable cells was also shown. Moreover, the enforced effects of the N,N'-dicyclohexylcarbodiimide (DCCD), inhibitor of H(+)-transporting F(0)F(1)-ATPase, on energy-dependent H(+) efflux by whole cells and of antibiotics like tetracycline and chloramphenicol on the following bacterial growth and survival were also determined after radiation. In addition, the lowering in DCCD-inhibited ATPase activity of membrane vesicles from exposed cells was defined. The results confirmed the input of membranous changes in bacterial action of low intensity extremely high frequency EMR, when the F(0)F(1)-ATPase is probably playing a key role. The radiation of bacteria might lead to changed metabolic pathways and to antibiotic resistance. It may also give bacteria with a specific role in biosphere.

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“…ATPase activity was estimated by the amount of P i released by membrane vesicles with ATP as described [11]. Right-side-out vesicles were used for ATPase assays.…”

Section: Atpase Assaymentioning

confidence: 99%

K+ influx by Kup in Escherichia coli is accompanied by a decrease in H+ efflux

Zakharyan¹

2001

FEMS Microbiology Letters

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Escherichia coli accumulates K by means of multiple uptake systems of which Kup is the major transport system at acidic pH. In cells grown under fermentative conditions at pH 5.5, K influx by a wild-type strain upon hyper-osmotic stress at pH 5.5 was accompanied by a marked decrease in H efflux, with a 1:1 ratio of K to H fluxes. This was observed with cells treated with N,NP-dicyclohexylcarbodiimide. Similar results with a mutant defective in Kdp and TrkA but with a functional Kup system but not in a mutant defective in Kdp and Kup but having an active TrkA system suggest that Kup operates as a H ^K -symporter. ß

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Relationship between the F0F1-ATPase and the K+-transport system within the membrane of anaerobically grownEscherichia coli. N,N?-dicyclohexylcarbodiimide-sensitive ATPase activity in mutants with defects in K+-transport

Cited by 46 publications

References 34 publications

Copper (II) Ions Affect Escherichia coli Membrane Vesicles’ SH-Groups and a Disulfide-Dithiol Interchange Between Membrane Proteins

Copper (II) Ions Affect Escherichia coli Membrane Vesicles’ SH-Groups and a Disulfide-Dithiol Interchange Between Membrane Proteins

Extremely High Frequency Electromagnetic Radiation Enforces Bacterial Effects of Inhibitors and Antibiotics

K+ influx by Kup in Escherichia coli is accompanied by a decrease in H+ efflux

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