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Delinois LJ, De León-Vélez O, Vázquez-Medina A, Vélez-Cabrera A, Marrero-Sánchez A, Nieves-Escobar C, Alfonso-Cano D, Caraballo-Rodríguez D, Rodriguez-Ortiz J, Acosta-Mercado J, Benjamín-Rivera JA, González-González K, Fernández-Adorno K, Santiago-Pagán L, Delgado-Vergara R, Torres-Ávila X, Maser-Figueroa A, Grajales-Avilés G, Miranda Méndez GI, Santiago-Pagán J, Nieves-Santiago M, Álvarez-Carrillo V, Griebenow K, Tinoco AD. Cytochrome c: Using Biological Insight toward Engineering an Optimized Anticancer Biodrug. INORGANICS 2021; 9:83. [PMID: 35978717 PMCID: PMC9380692 DOI: 10.3390/inorganics9110083] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The heme protein cytochrome c (Cyt c) plays pivotal roles in cellular life and death processes. In the respiratory chain of mitochondria, it serves as an electron transfer protein, contributing to the proliferation of healthy cells. In the cell cytoplasm, it activates intrinsic apoptosis to terminate damaged cells. Insight into these mechanisms and the associated physicochemical properties and biomolecular interactions of Cyt c informs on the anticancer therapeutic potential of the protein, especially in its ability to subvert the current limitations of small molecule-based chemotherapy. In this review, we explore the development of Cyt c as an anticancer drug by identifying cancer types that would be receptive to the cytotoxicity of the protein and factors that can be finetuned to enhance its apoptotic potency. To this end, some information is obtained by characterizing known drugs that operate, in part, by triggering Cyt c induced apoptosis. The application of different smart drug delivery systems is surveyed to highlight important features for maintaining Cyt c stability and activity and improving its specificity for cancer cells and high drug payload release while recognizing the continuing limitations. This work serves to elucidate on the optimization of the strategies to translate Cyt c to the clinical market.
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Affiliation(s)
- Louis J. Delinois
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Omar De León-Vélez
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Adriana Vázquez-Medina
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Alondra Vélez-Cabrera
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Amanda Marrero-Sánchez
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | | | - Daniela Alfonso-Cano
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | | | - Jael Rodriguez-Ortiz
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Jemily Acosta-Mercado
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Josué A. Benjamín-Rivera
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Kiara González-González
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Kysha Fernández-Adorno
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Lisby Santiago-Pagán
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Rafael Delgado-Vergara
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Xaiomy Torres-Ávila
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Andrea Maser-Figueroa
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | | | | | - Javier Santiago-Pagán
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Miguel Nieves-Santiago
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Vanessa Álvarez-Carrillo
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Kai Griebenow
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
| | - Arthur D. Tinoco
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, PR 00931, USA
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Slater JW, Marguet SC, Gray ME, Monaco HA, Sotomayor M, Shafaat HS. Power of the Secondary Sphere: Modulating Hydrogenase Activity in Nickel-Substituted Rubredoxin. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01720] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeffrey W. Slater
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Sean C. Marguet
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Michelle E. Gray
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Haleigh A. Monaco
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Marcos Sotomayor
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Hannah S. Shafaat
- The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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Bhagi-Damodaran A, Lu Y. The Periodic Table's Impact on Bioinorganic Chemistry and Biology's Selective Use of Metal Ions. STRUCTURE AND BONDING 2019; 182:153-173. [PMID: 36567794 PMCID: PMC9788643 DOI: 10.1007/430_2019_45] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Despite the availability of a vast variety of metal ions in the periodic table, biology uses only a selective few metal ions. Most of the redox active metals used belong to the first row of transition metals in the periodic table and include Fe, Co, Ni, Mn and Cu. On the other hand, Ca, Zn and Mg are the most commonly used redox inactive metals in biology. In this chapter, we discuss the periodic table's impact on bio-inorganic chemistry, by exploring reasons behind this selective choice of metals biology. A special focus is placed on the chemical and functional reasons why one metal ion is preferred over another one. We discuss the implications of metal choice in various biological processes including catalysis, electron transfer, redox sensing and signaling. We find that bioavailability of metal ions along with their redox potentials, coordination flexibility, valency and ligand affinity determine the specificity of metals for biological processes. Understanding the implications underlying the selective choice of metals of the periodic table in these biological processes can help design more efficient catalysts, more precise biosensors and more effective drugs.
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Affiliation(s)
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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Prieto T, Santana V, Britto AMM, Araujo-Chaves JC, R Nascimento O, L Nantes-Cardoso I. Structure and Catalysis of Fe(III) and Cu(II) Microperoxidase-11 Interacting with the Positively Charged Interfaces of Lipids. Molecules 2017; 22:molecules22081212. [PMID: 28933729 PMCID: PMC6151982 DOI: 10.3390/molecules22081212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 06/20/2017] [Accepted: 07/14/2017] [Indexed: 11/24/2022] Open
Abstract
Numerous applications have been described for microperoxidases (MPs) such as in photoreceptors, sensing, drugs, and hydrogen evolution. The last application was obtained by replacing Fe(III), the native central metal, by cobalt ion and inspired part of the present study. Here, the Fe(III) of MP-11 was replaced by Cu(II) that is also a stable redox state in aerated medium, and the structure and activity of both MPs were modulated by the interaction with the positively charged interfaces of lipids. Comparative spectroscopic characterization of Fe(III) and Cu(II)MP-11 in the studied media demonstrated the presence of high and low spin species with axial distortion. The association of the Fe(III)MP-11 with CTAB and Cu(II)MP-11 with DODAB affected the colloidal stability of the surfactants that was recovered by heating. This result is consistent with hydrophobic interactions of MPs with DODAB vesicles and CTAB micelles. The hydrophobic interactions decreased the heme accessibility to substrates and the Fe(III) MP-11catalytic efficiency. Cu(II)MP-11 challenged by peroxides exhibited a cyclic Cu(II)/Cu(I) interconversion mechanism that is suggestive of a mimetic Cu/ZnSOD (superoxide dismutase) activity against peroxides. Hydrogen peroxide-activated Cu(II)MP-11 converted Amplex Red® to dihydroresofurin. This study opens more possibilities for technological applications of MPs.
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Affiliation(s)
- Tatiana Prieto
- Universidade Federal do ABC, Santo André 09210-170, SP, Brazil.
| | - Vinicius Santana
- Universidade de São Paulo, Instituto de Física de São Carlos, São Carlos 13400-970, SP, Brazil.
| | | | | | - Otaciro R Nascimento
- Universidade de São Paulo, Instituto de Física de São Carlos, São Carlos 13400-970, SP, Brazil.
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Vitale R, Lista L, Lau-Truong S, Tucker RT, Brett MJ, Limoges B, Pavone V, Lombardi A, Balland V. Spectroelectrochemistry of FeIII- and CoIII-mimochrome VI artificial enzymes immobilized on mesoporous ITO electrodes. Chem Commun (Camb) 2014; 50:1894-6. [DOI: 10.1039/c3cc48489k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV-visible absorption spectroelectrochemistry elucidated the different redox behaviours of FeIII- and CoIII-mimochrome VI artificial enzymes, adsorbed on mesoporous conductive films of ITO.
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Affiliation(s)
- R. Vitale
- Department of Chemical Sciences
- Complesso Universitario Monte S. Angelo, University of Naples “Federico II”
- 80126 Naples, Italy
| | - L. Lista
- Department of Chemical Sciences
- Complesso Universitario Monte S. Angelo, University of Naples “Federico II”
- 80126 Naples, Italy
| | - S. Lau-Truong
- ITODYS
- UMR CNRS 7086
- Université Paris Diderot
- Sorbonne Paris Cité
- 75205 Paris Cedex 13, France
| | - R. T. Tucker
- Electrical and Computer Engineering
- University of Alberta
- Edmonton, Canada T6G 2V4
| | - M. J. Brett
- Electrical and Computer Engineering
- University of Alberta
- Edmonton, Canada T6G 2V4
- NRC National Institute for Nanotechnology
- Edmonton, Canada T6G 2M9
| | - B. Limoges
- Laboratoire d'Electrochimie Moléculaire
- Université Paris Diderot
- UMR CNRS 7591
- 75205 Paris Cedex 13, France
| | - V. Pavone
- Department of Chemical Sciences
- Complesso Universitario Monte S. Angelo, University of Naples “Federico II”
- 80126 Naples, Italy
| | - A. Lombardi
- Department of Chemical Sciences
- Complesso Universitario Monte S. Angelo, University of Naples “Federico II”
- 80126 Naples, Italy
| | - V. Balland
- Laboratoire d'Electrochimie Moléculaire
- Université Paris Diderot
- UMR CNRS 7591
- 75205 Paris Cedex 13, France
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Wójtowicz H, Bielecki M, Wojaczyński J, Olczak M, Smalley JW, Olczak T. The Porphyromonas gingivalis HmuY haemophore binds gallium(iii), zinc(ii), cobalt(iii), manganese(iii), nickel(ii), and copper(ii) protoporphyrin IX but in a manner different to iron(iii) protoporphyrin IX. Metallomics 2013; 5:343-51. [DOI: 10.1039/c3mt20215a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Fe-haem bound to Escherichia coli bacterioferritin accelerates iron core formation by an electron transfer mechanism. Biochem J 2012; 444:553-60. [DOI: 10.1042/bj20112200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BFR (bacterioferritin) is an iron storage and detoxification protein that differs from other ferritins by its ability to bind haem cofactors. Haem bound to BFR is believed to be involved in iron release and was previously thought not to play a role in iron core formation. Investigation of the effect of bound haem on formation of the iron core has been enabled in the present work by development of a method for reconstitution of BFR from Escherichia coli with exogenously added haem at elevated temperature in the presence of a relatively high concentration of sodium chloride. Kinetic analysis of iron oxidation by E. coli BFR preparations containing various amounts of haem revealed that haem bound to BFR decreases the rate of iron oxidation at the dinuclear iron ferroxidase sites but increases the rate of iron core formation. Similar kinetic analysis of BFR reconstituted with cobalt-haem revealed that this haem derivative has no influence on the rate of iron core formation. These observations argue that haem bound to E. coli BFR accelerates iron core formation by an electron-transfer-based mechanism.
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Smith AT, Majtan T, Freeman KM, Su Y, Kraus JP, Burstyn JN. Cobalt cystathionine β-synthase: a cobalt-substituted heme protein with a unique thiolate ligation motif. Inorg Chem 2011; 50:4417-27. [PMID: 21480614 PMCID: PMC3350334 DOI: 10.1021/ic102586b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human cystathionine β-synthase (hCBS), a key enzyme in the trans-sulfuration pathway, catalyzes the condensation of serine with homocysteine to produce cystathionine. CBS from higher organisms is the only known protein that binds pyridoxal-5'-phosphate (PLP) and heme. Intriguingly, the function of the heme in hCBS has yet to be elucidated. Herein, we describe the characterization of a cobalt-substituted variant of hCBS (Co hCBS) in which CoPPIX replaces FePPIX (heme). Co(III) hCBS is a unique Co-substituted heme protein: the Co(III) ion is 6-coordinate, low-spin, diamagnetic, and bears a cysteine(thiolate) as one of its axial ligands. The peak positions and intensities of the electronic absorption and MCD spectra of Co(III) hCBS are distinct from those of previously Co-substituted heme proteins; TD-DFT calculations reveal that the unique features arise from the 6-coordinate Co bound axially by cysteine(thiolate) and a neutral donor, presumably histidine. Reactivity of Co(III) hCBS with HgCl(2) is consistent with a loss of the cysteine(thiolate) ligand. Co(III) hCBS is slowly reduced to Co(II) hCBS, which contains a 5-coordinate, low-spin, S = 1/2 Co-porphyrin that does not retain the cysteine(thiolate) ligand; this form of Co(II) hCBS binds NO((g)) but not CO((g)). Co(II) hCBS is reoxidized in the air to form a new Co(III) form, which does not contain a cysteine(thiolate) ligand. Canonical and alternative CBS assays suggest that maintaining the native heme ligation motif of wild-type Fe hCBS (Cys/His) is essential in maintaining maximal activity in Co hCBS. Correlation between the coordination structures and enzyme activity in both native Fe and Co-substituted proteins implicates a structural role for the heme in CBS.
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Affiliation(s)
- Aaron T. Smith
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin, 53706 USA
| | - Tomas Majtan
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado 80045
- Department of Genomics & Biotechnology, Institute of Molecular Biology SAS, Dubravska cesta 21, Bratislava, 84551, Slovakia
| | - Katherine M. Freeman
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin, 53706 USA
| | - Yang Su
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin, 53706 USA
| | - Jan P. Kraus
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado 80045
| | - Judith N. Burstyn
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin, 53706 USA
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Majtan T, Freeman KM, Smith AT, Burstyn JN, Kraus JP. Purification and characterization of cystathionine β-synthase bearing a cobalt protoporphyrin. Arch Biochem Biophys 2011; 508:25-30. [PMID: 21262193 PMCID: PMC3063419 DOI: 10.1016/j.abb.2011.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 01/14/2011] [Accepted: 01/15/2011] [Indexed: 11/24/2022]
Abstract
Human cystathionine β-synthase (CBS), a pivotal enzyme in the metabolism of homocysteine, is a pyridoxal-5'-phosphate-dependent enzyme that also contains heme, a second cofactor whose function is still unclear. One strategy for elucidation of heme function is its replacement with different metalloporphyrins or with porphyrins containing different substituent groups. This paper describes a novel expression approach and purification of cobalt CBS (CoCBS), which results in a high yield of fully active, high purity enzyme, in which heme is substituted by Co-protoporphyrin IX (CoPPIX). Metal content analysis showed that the enzyme contained 92% cobalt and 8% iron. CoCBS was indistinguishable from wild-type FeCBS in its activity, tetrameric oligomerization, PLP saturation and responsiveness to the allosteric activator, S-adenosyl-l-methionine. The observed biochemical and spectral characteristics of CoCBS provide further support for the suggestion that heme is involved in structural integrity and folding of this unusual enzyme.
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Affiliation(s)
- Tomas Majtan
- Department of Pediatrics and the Colorado Intellectual and Developmental Disabilities Research Center (IDDRC), University of Colorado at Denver, 12800 E 19th Ave, Aurora, CO 80045, USA
- Department of Genomics & Biotechnology, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, 84551, Slovakia
| | | | - Aaron T. Smith
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Judith N. Burstyn
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Jan P. Kraus
- Department of Pediatrics and the Colorado Intellectual and Developmental Disabilities Research Center (IDDRC), University of Colorado at Denver, 12800 E 19th Ave, Aurora, CO 80045, USA
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Harvat EM, Daltrop O, Sobott F, Moreau M, Barker PD, Stevens JM, Ferguson SJ. Metal and redox selectivity of protoporphyrin binding to the heme chaperone CcmE. Metallomics 2011; 3:363-8. [DOI: 10.1039/c0mt00085j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Leu BM, Ching TH, Zhao J, Sturhahn W, Alp EE, Sage JT. Vibrational dynamics of iron in cytochrome C. J Phys Chem B 2009; 113:2193-200. [PMID: 19173569 DOI: 10.1021/jp806574t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nuclear resonance vibrational spectroscopy (NRVS) and Raman spectroscopy on (54)Fe- and (57)Fe-enriched cytochrome c (cyt c) identify multiple bands involving vibrations of the heme Fe. Comparison with predictions from Fe isotope shifts reveals that 70% of the NRVS signal in the 300-450 cm(-1) frequency range corresponds to vibrations resolved in Soret-enhanced Raman spectra. This frequency range dominates the "stiffness", an effective force constant determined by the Fe vibrational density of states (VDOS), which measures the strength of nearest-neighbor interactions with Fe. The stiffness of the low-spin Fe environment in both oxidation states of cyt c significantly exceeds that for the high-spin Fe in deoxymyoglobin, where the 200-300 cm(-1) frequency range dominates the VDOS. This situation is reflected in the shorter Fe-ligand bond lengths in the former with respect to the latter. The longer Fe-S(Met80) in oxidized cyt c with respect to reduced cyt c leads to a decrease in the stiffness of the iron environment upon oxidation. Comparison with NRVS measurements allows us to assess assignments for vibrational modes resolved in this region of the heme Raman spectrum. We consider the possibility that the 372 cm(-1) band in reduced cyt c involves the Fe-S(Met80) bond.
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Affiliation(s)
- Bogdan M Leu
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, USA
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Richard-Fogal CL, Frawley ER, Feissner RE, Kranz RG. Heme concentration dependence and metalloporphyrin inhibition of the system I and II cytochrome c assembly pathways. J Bacteriol 2006; 189:455-63. [PMID: 17085564 PMCID: PMC1797374 DOI: 10.1128/jb.01388-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Studies have indicated that specific heme delivery to apocytochrome c is a critical feature of the cytochrome c biogenesis pathways called system I and II. To determine directly the heme requirements of each system, including whether other metal porphyrins can be incorporated into cytochromes c, we engineered Escherichia coli so that the natural system I (ccmABCDEFGH) was deleted and exogenous porphyrins were the sole source of porphyrins (Delta hemA). The engineered E. coli strains that produced recombinant system I (from E. coli) or system II (from Helicobacter) facilitated studies of the heme concentration dependence of each system. Using this exogenous porphyrin approach, it was shown that in system I the levels of heme used are at least fivefold lower than the levels used in system II, providing an important advantage for system I. Neither system could assemble holocytochromes c with other metal porphyrins, suggesting that the attachment mechanism is specific for Fe protoporphyrin. Surprisingly, Zn and Sn protoporphyrins are potent inhibitors of the pathways, and exogenous heme competes with this inhibition. We propose that the targets are the heme binding proteins in the pathways (CcmC, CcmE, and CcmF for system I and CcsA for system II).
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Daltrop O, Ferguson SJ. In Vitro Studies on Thioether Bond Formation between Hydrogenobacter thermophilus Apocytochrome c552 with Metalloprotoporphyrin Derivatives. J Biol Chem 2004; 279:45347-53. [PMID: 15326165 DOI: 10.1074/jbc.m408637200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously, in vitro formation of thioether bonds between Hydrogenobacter thermophilus apocytochrome c(552) and Fe-protoporphyrin IX has been demonstrated. Now we report studies on the reaction between the metalloderivatives Zn-, Co-, and Mn-protoporphyrin IX and the cysteine thiols of H. thermophilus apocytochrome c(552). All of these metalloporphyrins were capable of forming a "b-type cytochrome" state in which the hydrophobic prosthetic group is bound non-covalently. Zn(II)-protoporphyrin IX attached to the polypeptide covalently in the presence of either dithiothreitol or tri(2-carboxyethyl)phosphine to keep the thiol moieties reduced. These data show that the chemical nature of the thiol-reducing agent does not interfere with the thioether bond-forming mechanism. Mn-porphyrin could only react with the protein in the divalent state of the metal ion. Co-porphyrin did not react with the cysteine thiols of the apocytochrome in either oxidation state of the metal. In the absence of a metal (i.e. protoporphyrin IX itself), no reactivity toward apocytochrome is observed. These results have significant implications for the chemical requirements for thioether bond formation of heme vinyl groups to cysteine thiols and also have potential applications in de novo design of metalloproteins.
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Affiliation(s)
- Oliver Daltrop
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, United Kingdom
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Qian C, Yao Y, Tong Y, Wang J, Tang W. Structural analysis of zinc-substituted cytochrome c. J Biol Inorg Chem 2003; 8:394-400. [PMID: 12761660 DOI: 10.1007/s00775-002-0428-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2002] [Accepted: 10/30/2002] [Indexed: 12/01/2022]
Abstract
Zinc-substituted cytochrome c has been widely used in studies of protein-protein interactions and photo-induced electron transfer reactions between proteins. However, the coordination geometry of zinc in zinc-substituted cyt c has not yet been determined; two different opinions about the coordination have been reached. Here the solution structures of zinc-substituted cytochrome c that might be five-coordinated and six-coordinated have been refined separately by using (1)H NMR spectroscopy, and the zinc coordination geometry was determined just by NOE distance constraints. Structural analysis of the energy-minimized average solution structures of both the pentacoordinated and hexacoordinated geometries indicate that that zinc in zinc-substituted cyt c should be bound to both His18 and Met80, which means that the zinc is six-coordinated. RMSD values of the family of 25 six-coordinated structures from the average structure are 0.66+/-0.13 A and 1.09+/-0.16 A for the backbone and all heavy atoms, respectively. A statistical analysis of the structure indicates its satisfactory quality. Comparison of the solution structure of the six-coordinated energy-minimized average structure of zinc-substituted cytochrome c with the solution structure of reduced cytochrome c reveals that for the overall folding the secondary structure elements are very close. The availability of the structure provides for a better understanding of the protein-protein complex and for electron transfer processes between Zn cyt c and other metalloproteins.
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Affiliation(s)
- Chengmin Qian
- State Key Laboratory of Coordination Chemistry, Nanjing University, 210093, Nanjing, PR China
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Tezcan FA, Findley WM, Crane BR, Ross SA, Lyubovitsky JG, Gray HB, Winkler JR. Using deeply trapped intermediates to map the cytochrome c folding landscape. Proc Natl Acad Sci U S A 2002; 99:8626-30. [PMID: 12084923 PMCID: PMC124336 DOI: 10.1073/pnas.132254499] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2002] [Indexed: 11/18/2022] Open
Abstract
Replacement of iron with cobalt(III) selectively introduces a deep trap in the folding-energy landscape of the heme protein cytochrome c. Remarkably, neither the protein structure nor the folding thermodynamics is perturbed by this metal-ion substitution, as shown by data from spectroscopic and x-ray diffraction experiments. Through kinetics measurements, we have found parallel folding pathways involving several different misligated Co(III) species, and, as these folding intermediates persist for several hours under certain conditions, we have been able to elucidate fully their spectroscopic properties. The results, along with an analysis of the fluorescence energy-transfer kinetics during refolding, show that rapidly equilibrating populations of compact and extended polypeptide conformations are present until all molecules have reached the native structure. These measurements provide direct evidence that collapsed denatured structures are not substantially more stable than extended conformations of cytochrome c.
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Affiliation(s)
- F Akif Tezcan
- Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
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Pasternack RF. Reduction of tetrakis(4-N-methylpyridyl)porphinecobalt(III) by hexaammineruthenium(II). Inorg Chem 2002. [DOI: 10.1021/ic50157a029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Garrou PE, Hartwell GE. Redistribution reactions of organometallic complexes. Carbonyl, halogen, and organophosphine exchange between coordinately unsaturated rhodium(I) and iridium(I) complexes. Inorg Chem 2002. [DOI: 10.1021/ic50157a030] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Shelnutt JA, Straub KD, Rentzepis PM, Gouterman M, Davidson ER. Core expansion and electronic structure of the porphyrin in the neutral pH form of copper cytochrome c. Biochemistry 2002. [DOI: 10.1021/bi00312a023] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Edwards AM, Zhang K, Nordgren CE, Blasie JK. Heme structure and orientation in single monolayers of cytochrome c on polar and nonpolar soft surfaces. Biophys J 2000; 79:3105-17. [PMID: 11106616 PMCID: PMC1301187 DOI: 10.1016/s0006-3495(00)76545-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Polarized x-ray absorption fine structure (XAFS) spectroscopy has been performed in fluorescence mode under total external reflection conditions on frozen hydrated single monolayers of yeast cytochrome c (YCC). The protein molecules were vectorially oriented within the monolayer by tethering their naturally occurring and unique surface cysteine residues to the sulfhydryl-endgroups at the surface of a mixed organic self-assembled monolayer, itself covalently attached to an ultrapure silicon wafer. The sulfhydryl-endgroups were isolated by dilution with either methyl- or hydroxyl-endgroups, producing macroscopically nonpolar or uncharged-polar soft surfaces, respectively. Independent information on the heme-plane orientation relative to the monolayer plane was obtained experimentally via optical linear dichroism. The polarized XAFS data have been analyzed both qualitatively and by a global mapping approach limited to systematically altering the various iron-ligand distances within a model for the local atomic environment of the heme prosthetic group, and comparing the theoretically generated XAFS spectra with those obtained experimentally. A similar analysis of unpolarized XAFS data from a frozen solution of YCC was performed using either the heme environment from the NMR solution or the x-ray crystallographic data for YCC as the model structure. All resulting iron-ligand distances were then used in molecular dynamics (MD) computer simulations of YCC in these three systems to investigate the possible effects of anisotropic ligand motions on the fits of the calculated to the experimental XAFS spectra.
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Affiliation(s)
- A M Edwards
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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23
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Edwards AM, Blasie JK, Bean JC. Vectorially oriented monolayers of the cytochrome c/cytochrome oxidase bimolecular complex. Biophys J 1998; 74:1346-57. [PMID: 9512031 PMCID: PMC1299481 DOI: 10.1016/s0006-3495(98)77847-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vectorially oriented monolayers of yeast cytochrome c and its bimolecular complex with bovine heart cytochrome c oxidase have been formed by self-assembly from solution. Both quartz and Ge/Si multilayer substrates were chemical vapor deposited with an amine-terminated alkylsiloxane monolayer that was then reacted with a hetero-bifunctional cross-linking reagent, and the resulting maleimide endgroup surface then provided for covalent interactions with the naturally occurring single surface cysteine 102 of the yeast cytochrome c. The bimolecular complex was formed by further incubating these cytochrome c monolayers in detergent-solubilized cytochrome oxidase. The sequential formation of such monolayers and the vectorially oriented nature of the cytochrome oxidase was studied via meridional x-ray diffraction, which directly provided electron density profiles of the protein(s) along the axis normal to the substrate plane. The nature of these profiles is consistent with previous work performed on vectorially oriented monolayers of either cytochrome c or cytochrome oxidase alone. Furthermore, optical spectroscopy has indicated that the rate of binding of cytochrome oxidase to the cytochrome c monolayer is an order of magnitude faster than the binding of cytochrome oxidase to an amine-terminated surface that was meant to mimic the ring of lysine residues around the heme edge of cytochrome c, which are known to be involved in the binding of this protein to cytochrome oxidase.
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Affiliation(s)
- A M Edwards
- Department of Chemistry, University of Pennsylvania, Philadelphia 19104-6323, USA.
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24
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Shen C, Kostić NM. Reductive Quenching of the Triplet State of Zinc Cytochrome c by the Hexacyanoferrate(II) Anion and by Conjugate Bases of Ethylenediaminetetraacetic Acid. Inorg Chem 1996. [DOI: 10.1021/ic9510270] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chengyu Shen
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Nenad M. Kostić
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
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25
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Local stabilities of horse cytochrome c metalloderivatives as probed by tryptic digestion and electrospray mass spectrometry. Inorganica Chim Acta 1996. [DOI: 10.1016/0020-1693(95)04876-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Ostropolska ŁL, Przywarska-Boniecka H, Swirska H. Interaction of iron(III) tetrasulphonated phthalocyanine with cytochrome c oxidase apoprotein. Polyhedron 1988. [DOI: 10.1016/s0277-5387(00)83890-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Alleyne TA, Wilson MT. Zinc cytochrome c fluorescence as a probe for conformational changes in cytochrome c oxidase. Biochem J 1987; 247:475-84. [PMID: 2827630 PMCID: PMC1148432 DOI: 10.1042/bj2470475] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Zinc cytochrome c forms tight 1:1 complexes with a variety of derivatives of cytochrome c oxidase. On complex-formation the fluorescence of zinc cytochrome c is diminished. Titrations of zinc cytochrome c with cytochrome c oxidase, followed through the fluorescence emission of the former, have yielded both binding constants (K approximately 7 x 10(6) M-1 for the fully oxidized and 2 x 10(7) M-1 for the fully reduced enzyme) and distance information. Comparison of steady-state measurements obtained by absorbance and fluorescence spectroscopy in the presence and in the absence of cyanide show that it is the reduction of cytochrome a and/or CuA that triggers a conformational change: this increases the zinc cytochrome c to acceptor (most probably cytochrome a itself) distance by some 0.5 nm. Ligand binding to the fully oxidized or fully reduced enzyme leaves the extent of fluorescence quenching unchanged, whereas binding of cyanide to the half-reduced enzyme (a2+CuA+CuB2+-CN(-)-a3(3+)) enhances fluorescence emission relative to that for the fully reduced enzyme, implying further relative movement of donor and acceptor.
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Affiliation(s)
- T A Alleyne
- Department of Chemistry, University of Essex, Colchester, U.K
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28
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Fee JA, Kuila D, Mather MW, Yoshida T. Respiratory proteins from extremely thermophilic, aerobic bacteria. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 853:153-85. [PMID: 3030415 DOI: 10.1016/0304-4173(86)90009-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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29
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30
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Przywarska-Boniecka H, Ostropolska L, Swirska H. Interaction between some metal tetrasulphonated phthalocyanines and apocytochrome-c. Polyhedron 1984. [DOI: 10.1016/s0277-5387(00)84726-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Yoshida T, Fee JA. Studies on cytochrome c oxidase activity of the cytochrome c1aa3 complex from Thermus thermophilus. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)43561-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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32
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Przywarska-Boniecka H, Ostropolska Z. Manganese (III) phthalocyanine-substituted cytochrome c. J Inorg Biochem 1983. [DOI: 10.1016/0162-0134(83)85017-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Antalis TM, Palmer G. Kinetic characterization of the interaction between cytochrome oxidase and cytochrome c. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(20)65125-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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34
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Przywarska-Boniecka H, Ostropolska L. Complexes of iron and cobalt tetrasulfonated phthalocyanines with apocytochrome c. J Inorg Biochem 1982; 16:183-99. [PMID: 6286874 DOI: 10.1016/s0162-0134(00)80106-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Artificial cytochromes c have been prepared with Fe(III) and Co(III) tetrasulfonated phthalocyanines in place of heme. Their structure and properties have been investigated by difference spectroscopy, CD, epr, electrophoresis, molecular weight estimation, and potentiometric measurements. The visible absorption spectra show the main peak at 650 nm for the iron compound 685 nm for the cobalt one. It is shown by CD experiments that incorporation of Fe(III)L or Co(III)L into apocytochrome c markedly increases helical content of the protein. Its conformation is, however, significantly altered as compared with the native cytochrome c. The epr and spectroscopic data show that the iron and cobalt phthalocyanine models represent the low spin species with the metal ions in trivalent state. Electrophoresis and molecular weight estimation indicate these complexes to be monomers. Both phthalocyanine complexes have not affinity for additional ligands characteristic for hemoglobin. They react, however, with CO, NO, and CN- when they are reduced with dithionite. Moreover, Co(II)L-apocyt c is able to combine with oxygen suggesting a structural feature in common with the oxygen-carrying heme proteins. Iron(II) complex in the same conditions is oxidized directly to the ferric state. The half-reduction potentials of Fe(III)L-apocyt c and Co(III)L-apocyt c are +374 mV and +320 mV, respectively. These complexes are reduced by cytochrome c and cytochrome c reductase (cytochrome bc1).
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35
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Veerman EC, Van Leeuwen JW, Van Buuren KJ, Van Gelder BF. The reaction of cytochrome aa3 with (porphyrin) cytochrome c as studied by pulse radiolysis. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 680:134-41. [PMID: 6284217 DOI: 10.1016/0005-2728(82)90004-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
(1) Using the pulse-radiolysis and stopped-flow techniques, the reactions of iron-free (porphyrin) cytochrome c and native cytochrome c with cytochrome aa3 were investigated. The porphyrin cytochrome c anion radical (generated by reduction of porphyrin cytochrome c by the hydrated electron) can transfer its electron to cytochrome aa3. The bimolecular rate constant for this reaction is 2 x 10(7) M-1 . s-1 (5 mM potassium phosphate, 0.5% Tween 20, pH 7.0, 20 degrees C). (2) The ionic strength dependence of the cytochrome c-cytochrome aa3 interaction was measured in the ionic strength range between 40 and 120 mM. At ionic strengths below 30 mM, a cytochrome c-cytochrome aa3 complex is formed in which cytochrome c is no longer reducible by the hydrated electron. A method is described by which the contributions of electrostatic forces to the reaction rate can be determined. (3) Using the stopped-flow technique, the effect of the dielectric constant (epsilon) of the reaction medium on the reaction of cytochrome C with cytochrome aa3 was investigated. With increasing epsilon the second-order rate constant decreased.
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36
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Chien J, Mayo K. Carp hemoglobin. I. Precise oxygen equilibrium and analysis according to the models of Adair and of Monod, Wyman, and Changeux. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43462-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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37
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Ikeda T, Kinoshita H, Yamane Y, Senda M. Polarographic Catalytic Currents Produced by Cytochromes c in Ammoniacal Buffers Containing Cobalt Ions. I. Significance of Heme Group. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1980. [DOI: 10.1246/bcsj.53.112] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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38
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Moore GR, Williams RJ, Chien JC, Dickson L. Nuclear magnetic resonance studies of metal substituted horse cytochrome c. J Inorg Biochem 1980. [DOI: 10.1016/s0162-0134(00)80039-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Abstract
The significance of the exposed haem edge in cytochrome c was directly probed by chemically modifying the partially exposed haem propionate in the crevice region around residues threonine-78 and threonine-49. Reaction of tuna heart cytochrome c with a water-soluble carbodi-imide at pH 3.7 in the absence of any added nucleophilic base leads to the covalent addition of substituted N-acylureas to the protein at two sites. One site has been shown to be a haem propionate by isotope-tracer and i.r.-spectral analysis of haem purified from the apoprotein. The other site is aspartial acid-62 on the back of the molecule. The modified cytochrome c demonstrates abnormal properties, including auto-oxidizability, a reduction potential of + 105mV, a reversible transition to a high-spin species below pH 5.3, no 695 nm charge-transfer band in the ferric state and abnormal binding to mitochondrial membranes. The derivative does react with cytochrome oxidase in deoxycholate-treated submitochondrial particles or in purified preparations with a specific activity of 43-65% compared with that obtained with native cytochrome c. The results are consistent with the view that an intact haem crevice is essential for normal values for physiochemical characteristics, but the significant residual enzymic activity suggests that the electron-transfer interface and/or the cytochrome oxidase-binding site cannot be localized solely in the region of the exposed haem propionate.
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Dickinson LC, Gibson HL, Chien JC. Reduction of methemoglobin by cobaltocytochrome c catalyzed by mediators. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 88:239-45. [PMID: 27361 DOI: 10.1111/j.1432-1033.1978.tb12443.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The reduction of methemoglobin by cobaltocytochrome c (Cocyt c) has been measured using nine mediators of different half-reduction potentials, Em, 7. The rate increases with the increase of Em, 7 for the mediator but dropped precipitously when it becomes more positive than the Em, 7 for the methemoglobin/hemoglobin couple. The reaction is most efficient with phenzaine methosulfate, therefore it was studied in detail. The reaction is first order in the concentrations of Cocyt c and phenazine methosulfate. The average second-order rate constant for Cocyt c + phenazine methosulfate (M) k1 leads to Cocyt c+ M-. is 2.9 x 10(4) M-1 s-1 at 25 degrees C, 0.1 M phosphate pH 7.0. There is a slight negative temperature dependence of k1 at low temperature; at higher temperatures the process has deltaH not equal to approximately 27 kJ mol-1 and deltaS not equal to approxmately - 75 J mol-1 K-1. The effect of anions reflects the dependence of Em, 7 for the methemoglobin/hemoglobin couple with various anions. There is no significant effect on k1 by the addition of inositol hexakisphosphate. The variation of k1 with pH is complicated. The experimental rate constants are compared with values calculated with the theory of nonadiabatic multiphonon process of electron tunneling.
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Erecińska M, Vanderkool JM. Modification of cytochrome c: modification of aromatic amino acids, photoaffinity labels, and metal substitution. Methods Enzymol 1978; 53:165-81. [PMID: 213676 DOI: 10.1016/s0076-6879(78)53022-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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45
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46
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Kirschenbaum DM. Molar absorptivity and A 1% 1cm values for proteins at selected wavelengths of the ultraviolet and visible regions. XIII. Anal Biochem 1977; 81:220-46. [PMID: 332005 DOI: 10.1016/0003-2697(77)90615-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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47
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Findlay MC, Chien CW. Nickel cytochrome c. Effect of protein moiety on the metal ion coordination. EUROPEAN JOURNAL OF BIOCHEMISTRY 1977; 76:79-83. [PMID: 18352 DOI: 10.1111/j.1432-1033.1977.tb11571.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nickel cytochrome c has been synthesized by the reaction of metal-free porphyrin cytochrome c with Ni(II) ions in 0.6 Mglycylglycine and 4 M KSCN. Electronic spectra and susceptibility measurement showed the nickel to be in a high-spin octahedral configuration exemplifying the strong influence of the protein moiety as a macrocyclic ligand on the coordination chemistry of the metal ion. Nickel cytochrome c has the same electrophoretic mobility, helicity and pK values of conformational transitions as the native enzyme. At high pH, the partially denatured nickel cytochrome c becomes dimeric. Nitric oxide reacts with nickel cytochrome c to form the nitrosyl derivative with (formula: see text). Reaction of NO with nickel protoporphyrin IX dimethyl ester in toluene, pyridine, or methylthioethanol produced no stable nitrosyl products, clearly demonstrating the effect of protein on metal ion ligation.
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48
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de Kok J, Butler J, Braams R, van Gelder BF. The reduction of porphyrin cytochrome c by hydrated electrons and the subsequent electron transfer reaction from reduced porphyrin cytochrome c to ferricytochrome c. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 460:290-8. [PMID: 192289 DOI: 10.1016/0005-2728(77)90215-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. Hydrated electrons, produced by pulse radiolysis react with porphyrin cytochrome c with a bimolecular rate constant of 3-10(10) M-1 S-1 at 21 degrees C and pH 7.4. 2. After the reduction step an absorbance change with a half-life of 5 microns is observed with the spectral range of 430-470 nm. A relatively stable intermediate then decays with a half-life of 15 s. 3. The spectrum of the intermediate observed 50 microns after the generation of hydrated electrons shows a broad absorption band between 600 and 700 nm and a peak at 408 nm. The spectrum is attributed to the protonated form of an initially produced porphyrin anion radical. 4. Reduced porphyrin cytochrome c reacts with ferricytochrome c with a bimolecular constant of 2-10(5) M-1- S-1 in 2 mM phosphate pH 7.4, at 21 degrees C and of 2 - 10(6) M-1-S-1 under the same conditions but at 1 M ionic strength. It is proposed that electron transfer in an analogous exchange reaction between ferrocytochrome c and ferricytochrome c occurs via the exposed part of the haem.
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49
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Vanderkooi JM, Adar F, Erecińska M. Metallocytochromes c: characterization of electronic absorption and emission spectra of Sn4+ and Zn2+ cytochromes c. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 64:381-7. [PMID: 179813 DOI: 10.1111/j.1432-1033.1976.tb10312.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tin (Sn4+) and zinc (Zn2+) derivatives of horse heart cytochrome c have been prepared and their optical spectra have been characterized. Zinc cytochrome c has visible absorption maxima at 549 and 585 nm and Soret absorption at 423 nm. Tin cytochrome c shows visible absorption maxima at 536 and 574 nm and Soret absorption at 410 nm. Unlike iron cytochrome c in which the emission spectrum of the porphyrin is almost completely quenched by the central metal, the zinc and tin derivatives of cytochrome c are both fluorescent and phosphorescent. The fluorescence maxima of zinc cytochrome c are at 590 and 640 nm and the fluorescence lifetime is 3.2 ns. The fluorescence maxima of Sn cytochrome are at 580 and 636 nm and the fluorescence lifetime is under 1 ns. The quantum yield of fluorescence is Zn greater than Sn while the quantum yield of phosphorescence is Sn greater than Zn. at 77 K the fluorescence and phosphorescence emission spectra of Sn and Zn cytochrome c show evidence of resolution into vibrational bands. The best resolved bands occur at frequency differences 750 cm-1 and 1540--1550 cm-1 from the O-O transition. These frequencies correspond with those obtained by resonance Raman spectroscopy for in-plane deformations of the porphyrin macrocycle.
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