Base de dados : MEDLINE
Pesquisa : D08.244.286.150 [Categoria DeCS]
Referências encontradas : 51 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 6 ir para página                

  1 / 51 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28097774
[Au] Autor:Fujii S; Oki H; Kawahara K; Yamane D; Yamanaka M; Maruno T; Kobayashi Y; Masanari M; Wakai S; Nishihara H; Ohkubo T; Sambongi Y
[Ad] Endereço:Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
[Ti] Título:Structural and functional insights into thermally stable cytochrome c' from a thermophile.
[So] Source:Protein Sci;26(4):737-748, 2017 Apr.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Thermophilic Hydrogenophilus thermoluteolus cytochrome c' (PHCP) exhibits higher thermal stability than a mesophilic counterpart, Allochromatium vinosum cytochrome c' (AVCP), which has a homo-dimeric structure and ligand-binding ability. To understand the thermal stability mechanism and ligand-binding ability of the thermally stable PHCP protein, the crystal structure of PHCP was first determined. It formed a homo-dimeric structure, the main chain root mean square deviation (rmsd) value between PHCP and AVCP being 0.65 Å. In the PHCP structure, six specific residues appeared to strengthen the heme-related and subunit-subunit interactions, which were not conserved in the AVCP structure. PHCP variants having altered subunit-subunit interactions were more severely destabilized than ones having altered heme-related interactions. The PHCP structure further revealed a ligand-binding channel and a penta-coordinated heme, as observed in the AVCP protein. A spectroscopic study clearly showed that some ligands were bound to the PHCP protein. It is concluded that the dimeric PHCP from the thermophile is effectively stabilized through heme-related and subunit-subunit interactions with conservation of the ligand-binding ability. BRIEF SUMMARY: We report the X-ray crystal structure of cytochrome c' (PHCP) from thermophilic Hydrogenophilus thermoluteolus. The high thermal stability of PHCP was attributed to heme-related and subunit-subunit interactions, which were confirmed by a mutagenesis study. The ligand-binding ability of PHCP was examined by spectrophotometry. PHCP acquired the thermal stability with conservation of the ligand-binding ability. This study furthers the understanding of the stability and function of cytochromes c.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Citocromos c´/química
Hydrogenophilaceae/enzimologia
Multimerização Proteica
[Mh] Termos MeSH secundário: Chromatiaceae/enzimologia
Cristalografia por Raios X
Estabilidade Enzimática
Temperatura Alta
Estrutura Quaternária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cytochromes c')
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170119
[St] Status:MEDLINE
[do] DOI:10.1002/pro.3120


  2 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27883268
[Au] Autor:Yamanaka M; Hoshizumi M; Nagao S; Nakayama R; Shibata N; Higuchi Y; Hirota S
[Ad] Endereço:Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
[Ti] Título:Formation and carbon monoxide-dependent dissociation of Allochromatium vinosum cytochrome c' oligomers using domain-swapped dimers.
[So] Source:Protein Sci;26(3):464-474, 2017 Mar.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The number of artificial protein supramolecules has been increasing; however, control of protein oligomer formation remains challenging. Cytochrome c' from Allochromatium vinosum (AVCP) is a homodimeric protein in its native form, where its protomer exhibits a four-helix bundle structure containing a covalently bound five-coordinate heme as a gas binding site. AVCP exhibits a unique reversible dimer-monomer transition according to the absence and presence of CO. Herein, domain-swapped dimeric AVCP was constructed and utilized to form a tetramer and high-order oligomers. The X-ray crystal structure of oxidized tetrameric AVCP consisted of two monomer subunits and one domain-swapped dimer subunit, which exchanged the region containing helices αA and αB between protomers. The active site structures of the domain-swapped dimer subunit and monomer subunits in the tetramer were similar to those of the monomer subunits in the native dimer. The subunit-subunit interactions at the interfaces of the domain-swapped dimer and monomer subunits in the tetramer were also similar to the subunit-subunit interaction in the native dimer. Reduced tetrameric AVCP dissociated to a domain-swapped dimer and two monomers upon CO binding. Without monomers, the domain-swapped dimers formed tetramers, hexamers, and higher-order oligomers in the absence of CO, whereas the oligomers dissociated to domain-swapped dimers in the presence of CO, demonstrating that the domain-swapped dimer maintains the CO-induced subunit dissociation behavior of native ACVP. These results suggest that protein oligomer formation may be controlled by utilizing domain swapping for a dimer-monomer transition protein.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Monóxido de Carbono/química
Chromatiaceae/enzimologia
Citocromos c´/química
[Mh] Termos MeSH secundário: Cristalografia por Raios X
Domínios Proteicos
Estrutura Quaternária de Proteína
Estrutura Secundária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cytochromes c'); 7U1EE4V452 (Carbon Monoxide)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161125
[St] Status:MEDLINE
[do] DOI:10.1002/pro.3090


  3 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26616515
[Au] Autor:Hough MA; Andrew CR
[Ad] Endereço:School of Biological Sciences, University of Essex, Colchester, United Kingdom.
[Ti] Título:Cytochromes c': Structure, Reactivity and Relevance to Haem-Based Gas Sensing.
[So] Source:Adv Microb Physiol;67:1-84, 2015.
[Is] ISSN:2162-5468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cytochromes c' are a group of class IIa cytochromes with pentacoordinate haem centres and are found in photosynthetic, denitrifying and methanotrophic bacteria. Their function remains unclear, although roles in nitric oxide (NO) trafficking during denitrification or in cellular defence against nitrosoative stress have been proposed. Cytochromes c' are typically dimeric with each c-type haem-containing monomer folding as a four-α-helix bundle. Their hydrophobic and crowded distal sites impose severe restrictions on the binding of distal ligands, including diatomic gases. By contrast, NO binds to the proximal haem face in a similar manner to that of the eukaryotic NO sensor, soluble guanylate cyclase and bacterial analogues. In this review, we focus on how structural features of cytochromes c' influence haem spectroscopy and reactivity with NO, CO and O2. We also discuss the relevance of cytochrome c' to understanding the mechanisms of gas binding to haem-based sensor proteins.
[Mh] Termos MeSH primário: Bactérias/enzimologia
Monóxido de Carbono/metabolismo
Citocromos c´/química
Citocromos c´/metabolismo
Heme/metabolismo
Óxido Nítrico/metabolismo
Oxigênio/metabolismo
[Mh] Termos MeSH secundário: Citocromos c'/genética
Modelos Moleculares
Ligação Proteica
Conformação Proteica
Análise Espectral
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Cytochromes c'); 31C4KY9ESH (Nitric Oxide); 42VZT0U6YR (Heme); 7U1EE4V452 (Carbon Monoxide); S88TT14065 (Oxygen)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:151130
[Lr] Data última revisão:
151130
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151201
[St] Status:MEDLINE


  4 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26100643
[Au] Autor:Ghafoor DD; Kekilli D; Abdullah GH; Dworkowski FS; Hassan HG; Wilson MT; Strange RW; Hough MA
[Ad] Endereço:Faculty of Science and Education Science, University of Sulaimani, Sulaymaniyah, Iraq.
[Ti] Título:Hydrogen bonding of the dissociated histidine ligand is not required for formation of a proximal NO adduct in cytochrome c'.
[So] Source:J Biol Inorg Chem;20(6):949-56, 2015 Sep.
[Is] ISSN:1432-1327
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Cytochromes c', that occur in methanotrophic, denitrifying and photosynthetic bacteria, form unusual proximal penta-coordinate NO complexes via a hexa-coordinate distal NO intermediate. Their NO binding properties are similar to those of the eukaryotic NO sensor, soluble guanylate cyclase, for which they provide a valuable structural model. Previous studies suggested that hydrogen bonding between the displaced proximal histidine (His120) ligand (following its dissociation from heme due to trans effects from the distally bound NO) and a conserved aspartate residue (Asp121) could play a key role in allowing proximal NO binding to occur. We have characterized three variants of Alcaligenes xylosoxidans cytochrome c' (AXCP) where Asp121 has been replaced by Ala, Ile and Gln, respectively. In all variants, hydrogen bonding between residue 121 and His120 is abolished yet 5-coordinate proximal NO species are still formed. Our data therefore demonstrate that the His120-Asp121 bond is not essential for proximal NO binding although it likely provides an energy minimum for the displaced His ligand. All variants have altered proximal pocket structure relative to native AXCP.
[Mh] Termos MeSH primário: Citocromos c´/química
Histidina/química
Óxido Nítrico/química
[Mh] Termos MeSH secundário: Achromobacter denitrificans
Citocromos c'/ultraestrutura
Ligações de Hidrogênio
Ligantes
Modelos Moleculares
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochromes c'); 0 (Ligands); 31C4KY9ESH (Nitric Oxide); 4QD397987E (Histidine)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150624
[St] Status:MEDLINE
[do] DOI:10.1007/s00775-015-1278-y


  5 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25961377
[Au] Autor:Servid AE; McKay AL; Davis CA; Garton EM; Manole A; Dobbin PS; Hough MA; Andrew CR
[Ti] Título:Resonance Raman Spectra of Five-Coordinate Heme-Nitrosyl Cytochromes c': Effect of the Proximal Heme-NO Environment.
[So] Source:Biochemistry;54(21):3320-7, 2015 Jun 02.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Five-coordinate heme nitrosyl complexes (5cNO) underpin biological heme-NO signal transduction. Bacterial cytochromes c' are some of the few structurally characterized 5cNO proteins, exhibiting a distal to proximal 5cNO transition of relevance to NO sensing. Establishing how 5cNO coordination (distal vs proximal) depends on the heme environment is important for understanding this process. Recent 5cNO crystal structures of Alcaligenes xylosoxidans cytochrome c' (AXCP) and Shewanella frigidimarina cytochrome c' (SFCP) show a basic residue (Arg124 and Lys126, respectively) near the proximal NO binding sites. Using resonance Raman (RR) spectroscopy, we show that structurally characterized 5cNO complexes of AXCP variants and SFCP exhibit a range of ν(NO) (1651-1671 cm(-1)) and ν(FeNO) (519-536 cm(-1)) vibrational frequencies, depending on the nature of the proximal heme pocket and the sample temperature. While the AXCP Arg124 residue appears to have little impact on 5cNO vibrations, the ν(NO) and ν(FeNO) frequencies of the R124K variant are consistent with (electrostatically) enhanced Fe(II) → (NO)π* backbonding. Notably, RR frequencies for SFCP and R124A AXCP are significantly displaced from the backbonding trendline, which in light of recent crystallographic data and density functional theory modeling may reflect changes in the Fe-N-O angle and/or extent of σ-donation from the NO(π*) to the Fe(II) (dz(2)) orbital. For R124A AXCP, correlation of vibrational and crystallographic data is complicated by distal and proximal 5cNO populations. Overall, this study highlights the complex structure-vibrational relationships of 5cNO proteins that allow RR spectra to distinguish 5cNO coordination in certain electrostatic and steric environments.
[Mh] Termos MeSH primário: Alcaligenes/enzimologia
Citocromos c´/química
Heme/química
Óxido Nítrico/química
Shewanella/enzimologia
Análise Espectral Raman
[Mh] Termos MeSH secundário: Alcaligenes/química
Modelos Moleculares
Shewanella/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Cytochromes c'); 31C4KY9ESH (Nitric Oxide); 42VZT0U6YR (Heme)
[Em] Mês de entrada:1508
[Cu] Atualização por classe:150602
[Lr] Data última revisão:
150602
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150512
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.5b00227


  6 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25792378
[Au] Autor:Manole A; Kekilli D; Svistunenko DA; Wilson MT; Dobbin PS; Hough MA
[Ad] Endereço:School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK.
[Ti] Título:Conformational control of the binding of diatomic gases to cytochrome c'.
[So] Source:J Biol Inorg Chem;20(4):675-86, 2015 Jun.
[Is] ISSN:1432-1327
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The cytochromes c' (CYTcp) are found in denitrifying, methanotrophic and photosynthetic bacteria. These proteins are able to form stable adducts with CO and NO but not with O2. The binding of NO to CYTcp currently provides the best structural model for the NO activation mechanism of soluble guanylate cyclase. Ligand binding in CYTcps has been shown to be highly dependent on residues in both the proximal and distal heme pockets. Group 1 CYTcps typically have a phenylalanine residue positioned close to the distal face of heme, while for group 2, this residue is typically leucine. We have structurally, spectroscopically and kinetically characterised the CYTcp from Shewanella frigidimarina (SFCP), a protein that has a distal phenylalanine residue and a lysine in the proximal pocket in place of the more common arginine. Each monomer of the SFCP dimer folds as a 4-alpha-helical bundle in a similar manner to CYTcps previously characterised. SFCP exhibits biphasic binding kinetics for both NO and CO as a result of the high level of steric hindrance from the aromatic side chain of residue Phe 16. The binding of distal ligands is thus controlled by the conformation of the phenylalanine ring. Only a proximal 5-coordinate NO adduct, confirmed by structural data, is observed with no detectable hexacoordinate distal NO adduct.
[Mh] Termos MeSH primário: Monóxido de Carbono/química
Citocromos c´/química
Óxido Nítrico/química
[Mh] Termos MeSH secundário: Sítios de Ligação
Monóxido de Carbono/metabolismo
Citocromos c'/metabolismo
Conformação Molecular
Óxido Nítrico/metabolismo
Shewanella/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochromes c'); 31C4KY9ESH (Nitric Oxide); 7U1EE4V452 (Carbon Monoxide)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150321
[St] Status:MEDLINE
[do] DOI:10.1007/s00775-015-1253-7


  7 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25519852
[Au] Autor:Kimura Y; Kasuga S; Unno M; Furusawa T; Osoegawa S; Sasaki Y; Ohno T; Wang-Otomo ZY
[Ad] Endereço:Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada, Kobe, 657-8501, Japan, ykimura@people.kobe-u.ac.jp.
[Ti] Título:The roles of C-terminal residues on the thermal stability and local heme environment of cytochrome c' from the thermophilic purple sulfur bacterium Thermochromatium tepidum.
[So] Source:Photosynth Res;124(1):19-29, 2015 Apr.
[Is] ISSN:1573-5079
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:A soluble cytochrome (Cyt) c' from thermophilic purple sulfur photosynthetic bacterium Thermochromatium (Tch.) tepidum exhibits marked thermal tolerance compared with that from the closely related mesophilic counterpart Allochromatium vinosum. Here, we focused on the difference in the C-terminal region of the two Cyts c' and examined the effects of D131 and R129 mutations on the thermal stability and local heme environment of Cyt c' by differential scanning calorimetry (DSC) and resonance Raman (RR) spectroscopy. In the oxidized forms, D131K and D131G mutants exhibited denaturing temperatures significantly lower than that of the recombinant control Cyt c'. In contrast, R129K and R129A mutants denatured at nearly identical temperatures with the control Cyt c', indicating that the C-terminal D131 is an important residue maintaining the enhanced thermal stability of Tch. tepidum Cyt c'. The control Cyt c' and all of the mutants increased their thermal stability upon the reduction. Interestingly, D131K exhibited narrow DSC curves and unusual thermodynamic parameters in both redox states. The RR spectra of the control Cyt c' exhibited characteristic bands at 1,635 and 1,625 cm(-1), ascribed to intermediate spin (IS) and high spin (HS) states, respectively. The IS/HS distribution was differently affected by the D131 and R129 mutations and pH changes. Furthermore, R129 mutants suggested the lowering of their redox potentials. These results strongly indicate that the D131 and R129 residues play significant roles in maintaining the thermal stability and modulating the local heme environment of Tch. tepidum Cyt c'.
[Mh] Termos MeSH primário: Chromatiaceae/metabolismo
Citocromos c´/química
Citocromos c´/metabolismo
Heme/metabolismo
Temperatura Ambiente
[Mh] Termos MeSH secundário: Varredura Diferencial de Calorimetria
Cristalografia por Raios X
Proteínas Mutantes/metabolismo
Desnaturação Proteica
Estabilidade Proteica
Análise Espectral Raman
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochromes c'); 0 (Mutant Proteins); 42VZT0U6YR (Heme)
[Em] Mês de entrada:1601
[Cu] Atualização por classe:171101
[Lr] Data última revisão:
171101
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141219
[St] Status:MEDLINE
[do] DOI:10.1007/s11120-014-0069-6


  8 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:24078591
[Au] Autor:Pietra F
[Ad] Endereço:Accademia Lucchese di Scienze, Lettere e Arti, Classe di Scienze, Palazzo Ducale, Lucca I-55100 (phone/fax: +39-0583-417336). francesco.pietra@accademialucchese.it.
[Ti] Título:Gates and binding pockets for nitric oxide with cytochrome c', according to molecular dynamics.
[So] Source:Chem Biodivers;10(9):1574-88, 2013 Sep.
[Is] ISSN:1612-1880
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Random-acceleration molecular-dynamics (RAMD) simulations with models of homodimeric 6-ligated distal-NO and 5-ligated proximal-NO cytochrome c' complexes, in TIP3 H2 O, showed two distinct, non-intercommunicating worlds. In the framework of a long cavity formed by four protein helices with heme at one extremity, NO was observed to follow different pathways with the two complexes to reach the solvent. With the 6-ligated complex, NO was observed to progress by exploiting protein internal channels created by thermal fluctuations, and be temporarily trapped into binding pockets before reaching the preferred gate at the heme end of the cavity. In contrast, with the 5-ligated complex, NO was observed to surface the solvent-exposed helix 7, up to a gate at the other extremity of the protein, only occasionally finding an earlier, direct way out toward the solvent. That only bulk NO gets involved in forming the 5-ligated proximal-NO complex is in agreement with previous experimental observations, while the occurrence of binding pockets suggests that also reservoir NO might play a role with the distal-NO complex.
[Mh] Termos MeSH primário: Citocromos c´/química
Simulação de Dinâmica Molecular
[Mh] Termos MeSH secundário: Alcaligenes/metabolismo
Sítios de Ligação
Citocromos c'/metabolismo
Óxido Nítrico/química
Óxido Nítrico/metabolismo
Estrutura Terciária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cytochromes c'); 31C4KY9ESH (Nitric Oxide)
[Em] Mês de entrada:1404
[Cu] Atualização por classe:130930
[Lr] Data última revisão:
130930
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:131001
[St] Status:MEDLINE
[do] DOI:10.1002/cbdv.201300164


  9 / 51 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:23924718
[Au] Autor:Fujii S; Masanari M; Inoue H; Yamanaka M; Wakai S; Nishihara H; Sambongi Y
[Ad] Endereço:Graduate School of Biosphere Science, Hiroshima University.
[Ti] Título:High thermal stability and unique trimer formation of cytochrome c' from thermophilic Hydrogenophilus thermoluteolus.
[So] Source:Biosci Biotechnol Biochem;77(8):1677-81, 2013.
[Is] ISSN:1347-6947
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Sequence analysis indicated that thermophilic Hydrogenophilus thermoluteolus cytochrome c' (PHCP) and its mesophilic homolog, Allochromatium vinosum cytochrome c' (AVCP), closely resemble each other in a phylogenetic tree of the cytochrome c' family, with 55% sequence identity. The denaturation temperature of PHCP was 87 °C, 35 °C higher than that of AVCP. Furthermore, PHCP exhibited a larger enthalpy change value during its thermal denaturation than AVCP. While AVCP was dimeric, as observed previously, PHCP was trimeric, and this was the first observation as a cytochrome c'. Dissociation of trimeric PHCP and its protein denaturation reversibly occurred at the same time in a two-state transition manner. Therefore, PHCP is enthalpically more stable than AVCP, perhaps due to its unique trimeric form, in addition to the lower number of Gly residues in its putative α-helical regions.
[Mh] Termos MeSH primário: Chromatiaceae/enzimologia
Citocromos c´/química
Estabilidade Enzimática
Hydrogenophilaceae/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Temperatura Alta
Filogenia
Desnaturação Proteica
Termodinâmica
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochromes c')
[Em] Mês de entrada:1404
[Cu] Atualização por classe:130827
[Lr] Data última revisão:
130827
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130809
[St] Status:MEDLINE


  10 / 51 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:22827326
[Au] Autor:Hirano Y; Kimura Y; Suzuki H; Miki K; Wang ZY
[Ad] Endereço:Faculty of Science, Ibaraki University, Mito 310-8512, Japan.
[Ti] Título:Structure analysis and comparative characterization of the cytochrome c' and flavocytochrome c from thermophilic purple photosynthetic bacterium Thermochromatium tepidum.
[So] Source:Biochemistry;51(33):6556-67, 2012 Aug 21.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The thermodynamic and spectroscopic properties of two soluble electron transport proteins, cytochrome (Cyt) c' and flavocytochrome c, isolated from thermophilic purple sulfur bacterium Thermochromatium (Tch.) tepidum were examined and compared with those of the corresponding proteins from a closely related mesophilic bacterium Allochromatium (Alc.) vinosum. These proteins share sequence identities of 82% for the cytochromes c' and 86% for the flavocytochromes c. Crystal structures of the two proteins have been determined at high resolutions. Differential scanning calorimetry and denaturing experiments show that both proteins from Tch. tepidum are thermally and structurally much more stable than their mesophilic counterparts. The denaturation temperature of Tch. tepidum Cyt c' was 22 °C higher than that of Alc. vinosum Cyt c', and the midpoints of denaturation using guanidine hydrochloride were 2.0 and 1.2 M for the Tch. tepidum and Alc. vinosum flavocytochromes c, respectively. The enhanced stabilities can be interpreted on the basis of the structural and sequence information obtained in this study: increased number of hydrogen bonds formed between main chain nitrogen and oxygen atoms, more compact structures and reduced number of glycine residues. Many residues with large side chains in Alc. vinosum Cyt c' are substituted by alanines in Tch. tepidum Cyt c'. Both proteins from Tch. tepidum exhibit high structural similarities to their counterparts from Alc. vinosum, and the different residues between the corresponding proteins are mainly located on the surface and exposed to the solvent. Water molecules are found in the heme vicinity of Tch. tepidum Cyt c' and form hydrogen bonds with the heme ligand and C-terminal charged residues. Similar bound waters are also found in the vicinity of one heme group in the diheme subunit of Tch. tepidum flavocytochrome c. Electron density map of the Tch. tepidum flavocytochrome c clearly revealed the presence of disulfur atoms positioned between two cysteine residues at the active site near the FAD prosthetic group. The result strongly suggests that flavocytochrome c is involved in the sulfide oxidation in vivo. Detailed discussion is given on the relationships between the crystal structures and the spectroscopic properties observed for these proteins.
[Mh] Termos MeSH primário: Grupo dos Citocromos c/química
Citocromos c´/química
Flavoproteínas/química
Oxirredutases/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Varredura Diferencial de Calorimetria
Chromatiaceae/química
Cristalização
Cristalografia por Raios X
Modelos Moleculares
Estabilidade Proteica
Alinhamento de Sequência
Termodinâmica
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochrome c Group); 0 (Cytochromes c'); 0 (Flavoproteins); EC 1.- (Oxidoreductases); EC 1.8.2.- (flavocytochrome c sulfide dehydrogenase)
[Em] Mês de entrada:1210
[Cu] Atualização por classe:120821
[Lr] Data última revisão:
120821
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120726
[St] Status:MEDLINE
[do] DOI:10.1021/bi3005522



página 1 de 6 ir para página                
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde