Electron-transfer studies with the CuA domain of Thermus thermophilus cytochrome ba3

Slutter, Claire E.; Langen, Ralf; Sanders, Donita; Lawrence, Stephen M; Wittung, Pernilla; Bilio, Angel J. Di; Hill, Michael G.; Fee, James A.; Richards, John H.; Winkler, Jay R.; Malmström, Bo G.

doi:10.1016/0020-1693(95)04901-0

Cited by 18 publications

(13 citation statements)

References 19 publications

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“…These fast ET rates approach the fastest synthetic mono- and dicopper system (10 5 to 10 6 M −1 s −1 ) 33,35–43 as well as Nature's blue copper ET protein 10 5 to 10 6 M −1 s −1 . 44,45 The corresponding reorganization energies for 4a / 4b and 4b / 4c were calculated to be 1.21(1) eV and 1.21(1) eV using eqn (1) ( Z = 10 11 M −1 s −1 , T = 298 K). 39,46 …”

Section: Resultsmentioning

confidence: 99%

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

2021

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Section: Resultsmentioning

confidence: 99%

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

2021

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“…The number of electrons transferred per enzymatic functional unit (inset of Figure 1) is, under all conditions, considerably less than two (a value expected, in analogy to beef heart oxidase, if complete reduction of Cu A and cyt b occurred). Since the redox potentials of cyt c 552 [230 mV (31)] and Cu A of uncomplexed ba 3 [250 mV, as determined at pH 8 in the isolated Cu A domain (32)] are quite "normal", in cyanide-bound ba 3 the redox potential of the Cu A -cyt b pair may be drastically lowered. This hypothesis, though far from being proven, is consistent with the finding that in these experiments cyt b is only partially reduced (<75%), as inferred from the absorption changes recorded at 410 nm, a wavelength isosbestic for cyt c 552 (not shown).…”

Section: Resultsmentioning

confidence: 99%

Kinetic Properties of ba₃ Oxidase from Thermus thermophilus: Effect of Temperature

et al. 1998

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The kinetic properties of the ba3 oxidase from Thermus thermophilus were investigated by stopped-flow spectroscopy in the temperature range of 5-70 degrees C. Peculiar behavior in the reaction with physiological substrates and classical ligands (CO and CN-) was observed. In the O2 reaction, the decay of the F intermediate is significantly slower (k' = 100 s-1 at 5 degrees C) than in the mitochondrial enzyme, with an activation energy E of 10.1 +/- 0.9 kcal mol-1. The cyanide-inhibited ba3 oxidizes cyt c522 quickly (k approximately 5 x 10(6) M-1 s-1 at 25 degrees C) and selectively, with an activation energy E of 10.9 +/- 0.9 kcal mol-1, but slowly oxidizes ruthenium hexamine, a fast electron donor for the mitochondrial enzyme. Cyt c552 oxidase activity is enhanced up to 60 degrees C and is maximal at extremely low ionic strengths, excluding formation of a high-affinity cyt c522-ba3 electrostatic complex. The thermophilic oxidase is less sensitive to cyanide inhibition, although cyanide binding under turnover is much quicker (seconds) than in the fully oxidized state (days). Finally, the affinity of reduced ba3 for CO at 20 degrees C (Keq = 1 x 10(5) M-1) was found to be smaller than that of beef heart aa3 (Keq = 4 x 10(6) M-1), partly because of an unusually fast, strongly temperature-dependent CO dissociation from cyt a32+ of ba3 (k' = 0.8 s-1 vs k' = 0.02 s-1 for beef heart aa3 at 20 degrees C). The relevance of these results to adaptation of respiratory activity to high temperatures and low environmental O2 tensions is discussed.

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“…For instance, the C c O is a membrane protein containing two heme groups (heme a and heme a 3 ), two copper centers (Cu A and Cu B ), a zinc ion, and a magnesium ion. To overcome these inherent difficulties in studying native Cu A centers, two strategies are developed: producing truncates of native proteins containing Cu A sites 742 , 1331 , 1339 , 1341 , 1342 , 1345 , 1352 , 1358 − 1361 and designing Cu A centers into small, soluble proteins. 1318 , 1362 , 1363 …”

Section: Copper Redox Centers In Electron Transfer Processesmentioning

confidence: 99%

“…This way, a water-soluble protein containing only the Cu A site was obtained. Such truncates have been constructed for C c O from B. subtilis , 1345 Pa. dentrificans , 742 , 1339 , 1358 , 1361 Procambarus versutus , 1360 Synechocystis PCC 6803, 1352 and T. thermophilus ( 1341 , 1342 , 1359 , 1361 ) and for SoxH from Sl. acidocaldarius .…”

Section: Copper Redox Centers In Electron Transfer Processesmentioning

confidence: 99%

Metalloproteins Containing Cytochrome, Iron–Sulfur, or Copper Redox Centers

et al. 2014

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Blue Type I Copper Centers vs Purple Cu A Centers 4439 5. Enzymes Employing a Combination of Different Types of Electron Transfer Centers 4439 5.1. Enzymes Using Both Heme and Cu as Electron Transfer Centers 4439 5.1.1. Cytochrome c and Cu A as Redox Partners to Cytochrome c Oxidases 4439 5.1.2. Cu A and Heme b as Redox Partners to Nitric Oxide Reductases 4440 5.1.3. Cytochrome c and Cu A as Redox Partners to Nitrous Oxide Reductases 4440 5.2. Enzymes Using Both Heme and Iron−Sulfur Clusters as Electron Transfer Centers 4440 5.2.1. As Redox Partners to the Cytochrome bc 1 Complex 4440 5.2.2. As Redox Partners to the Cytochrome b 6 f Complex 4442 5.2.3. As Redox Centers in Formate Dehydrogenases 4443 5.2.4. As Redox Centers in Nitrate Reductase 4443 6. Summary and Outlook 4443 Author Information 4445 Corresponding Author 4445 Author Contributions 4445 Notes 4445 Biographies 4445 Acknowledgments 4447 Abbreviations 4447 References 4447

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Electron-transfer studies with the CuA domain of Thermus thermophilus cytochrome ba3

Cited by 18 publications

References 19 publications

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

Kinetic Properties of ba₃ Oxidase from Thermus thermophilus: Effect of Temperature

Metalloproteins Containing Cytochrome, Iron–Sulfur, or Copper Redox Centers

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Electron-transfer studies with the CuA domain of Thermus thermophilus cytochrome ba3

Cited by 18 publications

References 19 publications

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from CuICuICuI to CuIICuIICuII states

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from CuICuICuI to CuIICuIICuII states

Kinetic Properties of ba3 Oxidase from Thermus thermophilus: Effect of Temperature

Metalloproteins Containing Cytochrome, Iron–Sulfur, or Copper Redox Centers

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Product

Resources

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Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

Encapsulation of tricopper cluster in a synthetic cryptand enables facile redox processes from Cu^ICu^ICu^I to Cu^IICu^IICu^II states

Kinetic Properties of ba₃ Oxidase from Thermus thermophilus: Effect of Temperature