1999
DOI: 10.1007/s007750050291
|View full text |Cite
|
Sign up to set email alerts
|

Abstract: A comparative study of the pH-dependent redox mechanisms of several members of the cytochrome c3 family has been carried out. In a previous work, the molecular determinants of this dependency (the so-called redox-Bohr effect) were investigated for one species using continuum electrostatic methods to find groups with a titrating range and strength of interaction compatible with a mediating role in the redox-Bohr effect. Here we clarify these aspects in the light of new and improved pKa calculations, our finding… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
2
1

Citation Types

6
77
1

Year Published

2001
2001
2020
2020

Publication Types

Select...
4
2
1

Relationship

3
4

Authors

Journals

citations
Cited by 41 publications
(84 citation statements)
references
References 2 publications
6
77
1
Order By: Relevance
“…Electrostatic calculations performed by using the crystal structure obtained at low pH as a basis have identified propionate 13 of haem I, propionate 13 of haem IV, and histidine 76 as likely candidates for the acid ± base groups participating in the redox-Bohr effect in this protein. [26] These calculations are supported by the values determined for the heterotropic interaction energies (see Table 1). Indeed: i) A very large negative value was determined for the interaction energy between centre V and haem I, suggesting the assignment of propionate 13 of haem I to centre V; and ii) relatively large and similar negative interaction energies were obtained between centre VI and haems II, III and IV, which indicates that both propionate 13 of haem IV and histidine 76 are likely to contribute to the effect assigned to centre VI, since no single acid ± base group is close to all these three haems.…”
Section: Discussionsupporting
confidence: 70%
See 1 more Smart Citation
“…Electrostatic calculations performed by using the crystal structure obtained at low pH as a basis have identified propionate 13 of haem I, propionate 13 of haem IV, and histidine 76 as likely candidates for the acid ± base groups participating in the redox-Bohr effect in this protein. [26] These calculations are supported by the values determined for the heterotropic interaction energies (see Table 1). Indeed: i) A very large negative value was determined for the interaction energy between centre V and haem I, suggesting the assignment of propionate 13 of haem I to centre V; and ii) relatively large and similar negative interaction energies were obtained between centre VI and haems II, III and IV, which indicates that both propionate 13 of haem IV and histidine 76 are likely to contribute to the effect assigned to centre VI, since no single acid ± base group is close to all these three haems.…”
Section: Discussionsupporting
confidence: 70%
“…These values were calculated iteratively from the thermodynamic parameters, since the existence of cooperativities in the intermediate redox stages modifies the pH dependence of the acid and base forms from a simple Henderson ± Hasselbalch equation. These values differ from those determined at 283 K in the absence of salt as expected, [25,26] since the equilibrium thermodynamic properties of tetrahaem cytochromes depend on ionic strength [27] and temperature. [13] The microscopic thermodynamic data reported in Table 1 can also be used to determine the pH-dependent macroscopic redox potentials associated with the four sequential one-electron steps necessary to fully reduce or oxidise this protein ( Figure 3).…”
Section: Resultscontrasting
confidence: 51%
“…The roles of propionate D of heme I and the free His (when it is present) seem to be a consistent feature over several Desulfovibrio species (18,29,30). In the oxidized structure there are no indications that either of the propionates of heme I is protonated at pH 7 in any of the possible conformers.…”
Section: Resultsmentioning
confidence: 65%
“…This shift leads to a steeper function, characteristic of positive cooperativity. To show that the conformational change occurring in Glu-61 (whose potential effect has previously been calculated (29)) is that responsible for this positive cooperativity, three mutants were modeled. The plot identified as "E61A" in Fig.…”
Section: Discussionmentioning
confidence: 99%
“…Numerous computational studies have attempted to predict pKa of organic compounds by applying different theoretical models [2][3][4][5][6][7][8][9][10][11][12][13]. Three main approaches have been employed in these theoretical models.…”
Section: Isrn Physical Chemistrymentioning
confidence: 99%