Cytochromesc‘:  Biological Models for theS=3/2,5/2Spin-State Admixture?

Weiss, Raymond; Gold, Avram; Terner, James

doi:10.1021/cr040416l

Cited by 128 publications

(170 citation statements)

References 207 publications

(752 reference statements)

Supporting

Mentioning

160

Contrasting

Order By: Relevance

“…The specific spin states have been assigned on the basis of magnetic susceptibility, EPR, resonance Raman, and NIR-region MCD spectral data. 14 The pH dependent unique electronic structures and the alkaline spinstate transitions of a number of Fe(III) Cyt c¤ proteins have been discussed. 24,25 The spin state of the heme iron of the type I form at pH 7 has been argued as either Fe(III) high spin, intermediate spin, or a mixture of both.…”

Section: Introductionmentioning

confidence: 99%

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

Takashina¹,

Tiedemann²,

Unno³

et al. 2016

Bulletin of the Chemical Society of Japan

View full text Add to dashboard Cite

The unusual magnetic/spectroscopic properties of Cytochrome c¤ (Cyt c¤) have been discussed, especially concerning the possibility of a quantum mechanically mixed-spin configuration of heme Fe(III). Here, four unique-spin species were identified from the magnetic circular dichroism (MCD) spectra of Cyt c¤ from Alcaligenes xylosoxidans (AxCyt c¤). The electrospray ionization mass spectrometric (ESI-MS) and circular dichroism (CD) spectroscopic data showed the overall conformation of AxCyt c¤ was unchanged, in complete contrast to the drastic changes in the heme MCD spectra over the range of pH 3.5 and 11.8. The pH dependency of ESI-MS, electronic absorption, MCD, and CD spectroscopic properties of AxCyt c¤ enabled us to reveal the undiscovered correlation between the protein-folding state and the electronic structure of the active site as a function of pH. The mechanism of alkaline spin-state transition through the rearrangement of the hydrogen-bonding linkage between Helix C and D is also proposed on the basis of atomic resolution crystal structure analyses (A. Takashina, M. Unno, T. Kohzuma, Chem. Lett. 2015, 44, 268).

show abstract

Section: Introductionmentioning

confidence: 99%

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

Takashina¹,

Tiedemann²,

Unno³

et al. 2016

Bulletin of the Chemical Society of Japan

View full text Add to dashboard Cite

show abstract

“…Its CO and NO binding properties have been applied in electrochemical [12,13] and fiberoptic fluorescent biosensors [14,15]. Most cytochromes c¢ are isolated as stable homodimers, although some occur as monomers or as a mixture of both [16]. Cytochrome c¢ from the purple photosynthetic bacterium Allochromatium vinosum (cyt-c¢) displays a unique dimer-to-monomer transition upon binding of NO, CO, CN -or small alkyl isocyanides [9,[17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Ligand-induced monomerization of Allochromatium vinosum cytochrome c′ studied using native mass spectrometry and fluorescence resonance energy transfer

et al. 2007

View full text Add to dashboard Cite

Cytochrome c¢ from Allochromatium vinosum is an attractive model protein to study ligand-induced conformational changes. This homodimeric protein dissociates into monomers upon binding of NO, CO or CN -to the iron of its covalently attached heme group. While ligand binding to the heme has been well characterized using a variety of spectroscopic techniques, direct monitoring of the subsequent monomerization has not been reported previously. Here we have explored two biophysical techniques to simultaneously monitor ligand binding and monomerization. Native mass spectrometry allowed the detection of the dimeric and monomeric forms of cytochrome c¢ and even showed the presence of a CO-bound monomer. The kinetics of the ligand-induced monomerization were found to be significantly enhanced in the gas phase compared with the kinetics in solution, however. Ligand binding to the heme and the dissociation of the dimer in solution were also studied using energy transfer from a fluorescent probe to both heme groups of the protein. Comparison of ligand binding kinetics as observed with UV-vis spectroscopy with changes in fluorescence suggested that binding of one CO molecule per dimer could be sufficient for monomerization.

show abstract

“…Bond distances and angles, atomic coordinates, anisotropic thermal parameters and hydrogen atom coordinates are given in Tables [FeTCPP] 2 ·16DMF can be described by using Z = 8, in accordance with the space group and the asymmetric unit. However, Z= 4 has been selected because this way the whole 65 dimer is represented in the chemical formula. …”

Section: Experimental Section Materialsmentioning

confidence: 99%

“…46,99 As observed in many biological and biomimetic iron porphyrin models, in the presence of an oxidizing agent, Fe IV -oxo complexes could be generated at the Fe III sites 100 which could efficiently catalyze the oxidation of alcohol to the respective aldehydes. This iron(IV)-oxo unit has a 65 Fe-O double character bond. Fe III sites are regenerated when the oxidation takes place.…”

Section: Oxidation Of Alcoholsmentioning

confidence: 99%

“…where x=J/kT (2) The van Vleck equation has been also used to estimate the exchange constant J due to the contribution of the monomeric species (χ mon ), but in this case for S = 1/2 in an axially distorted 65 octahedral environment (equation 3). In equation 3, D is the axial parameter related to the ZFS effect, The E rhombic one has been considered negligible.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Heterogeneous catalytic properties of unprecedented μ-O-[FeTCPP]₂dimers (H₂TCPP = meso-tetra(4-carboxyphenyl)porphyrin): an unusual superhyperfine EPR structure

et al. 2015

View full text Add to dashboard Cite

During the past years, a great effort has been devoted to the anchoring of catalysts into solid coordination networks in order to achieve heterogeneous catalysts. In this sense, an innovative approach consists on using the coordination-network synthons both as structural units and as catalysts. Regarding the latter, 10 metalloporphyrins are suitable candidates for synthons. In fact, a few works report on coordination compounds based on metalloporphyrins exhibiting these features. On the other hand, highly distorted diiron oxo dimers containing electron withdrawing groups rank amongst the most-effective catalyst models. Thus, the aim of this work was obtaining coordination networks based on iron porphyrins exhibiting those characteristics. This way, this work reports on the synthesis and characterisation of the µ-O- 15[FeTCPP] 2 ·16DMF compound (H 2 TCPP = meso-tetra(4-carboxyphenyl)porphyrin, DMF = N,Ndimethylformamide). This compound is the first example of an µ-oxo dimer with TCPP. The inter-dimer connections give rise to a laminar structure. The structural, spectroscopic and magnetic properties of this compound are consistent with the presence of high-spin Fe III ions, exhibiting a strong antiferromagnetic coupling in the µ-oxo dimer (J = -132 cm -1 ). An unusual superhyperfine structure has been observed in 20 EPR that is related to the high accessible volume of the compound. The structural features of the dimers and the accessible network are responsible for the excellent behaviour of the compound as a heterogeneous catalyst for different oxidation of alcohols. Therefore, this compound is a new of the very few examples of metalloporphyrins where structural units play as catalysts.

show abstract

Cytochromesc‘: Biological Models for theS=³/₂,⁵/₂Spin-State Admixture?

Cited by 128 publications

References 207 publications

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

Ligand-induced monomerization of Allochromatium vinosum cytochrome c′ studied using native mass spectrometry and fluorescence resonance energy transfer

Heterogeneous catalytic properties of unprecedented μ-O-[FeTCPP]₂dimers (H₂TCPP = meso-tetra(4-carboxyphenyl)porphyrin): an unusual superhyperfine EPR structure

Contact Info

Product

Resources

About

Cytochromesc‘: Biological Models for theS=3/2,5/2Spin-State Admixture?

Cited by 128 publications

References 207 publications

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

The pH Dependent Protein Structure Transitions and Related Spin-State Transition of Cytochrome c′ from Alcaligenes xylosoxidans NCIMB 11015

Ligand-induced monomerization of Allochromatium vinosum cytochrome c′ studied using native mass spectrometry and fluorescence resonance energy transfer

Heterogeneous catalytic properties of unprecedented μ-O-[FeTCPP]2dimers (H2TCPP = meso-tetra(4-carboxyphenyl)porphyrin): an unusual superhyperfine EPR structure

Contact Info

Product

Resources

About

Cytochromesc‘: Biological Models for theS=³/₂,⁵/₂Spin-State Admixture?

Heterogeneous catalytic properties of unprecedented μ-O-[FeTCPP]₂dimers (H₂TCPP = meso-tetra(4-carboxyphenyl)porphyrin): an unusual superhyperfine EPR structure