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1.
J Biol Chem ; 299(2): 102884, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36626983

RESUMO

Vacuolar/archaeal-type ATPase (V/A-ATPase) is a rotary ATPase that shares a common rotary catalytic mechanism with FoF1 ATP synthase. Structural images of V/A-ATPase obtained by single-particle cryo-electron microscopy during ATP hydrolysis identified several intermediates, revealing the rotary mechanism under steady-state conditions. However, further characterization is needed to understand the transition from the ground state to the steady state. Here, we identified the cryo-electron microscopy structures of V/A-ATPase corresponding to short-lived initial intermediates during the activation of the ground state structure by time-resolving snapshot analysis. These intermediate structures provide insights into how the ground-state structure changes to the active, steady state through the sequential binding of ATP to its three catalytic sites. All the intermediate structures of V/A-ATPase adopt the same asymmetric structure, whereas the three catalytic dimers adopt different conformations. This is significantly different from the initial activation process of FoF1, where the overall structure of the F1 domain changes during the transition from a pseudo-symmetric to a canonical asymmetric structure (PNAS NEXUS, pgac116, 2022). In conclusion, our findings provide dynamical information that will enhance the future prospects for studying the initial activation processes of the enzymes, which have unknown intermediate structures in their functional pathway.


Assuntos
Trifosfato de Adenosina , ATPases Vacuolares Próton-Translocadoras , Trifosfato de Adenosina/metabolismo , Domínio Catalítico , Microscopia Crioeletrônica , ATPases Vacuolares Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/metabolismo , Ativação Enzimática , Conformação Proteica
2.
Pharmacol Res ; 209: 107423, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39303772

RESUMO

Practical and conceptual barriers have kept human F-ATP synthase out of reach as a target for the treatment of human diseases. Although this situation has persisted for decades, it may change in the near future. In this review the principal functionalities of human F-ATP synthase--proton motive force / ATP interconversion, membrane bending and mitochondrial permeability transition--are surveyed in the context of their respective potential for pharmaceutical intervention. Further, the technical requirements necessary to allow drug designs that are effective at the multiple levels of functionality and modality of human F-ATP synthase are discussed. The structure-based development of gastric proton pump inhibitors is used to exemplify what might be feasible for human F-ATP synthase. And finally, four structural regions of the human F-ATP synthase are examined as potential sites for the development of structure based drug development.

3.
Artigo em Inglês | MEDLINE | ID: mdl-39132971

RESUMO

BACKGROUND AND AIMS: Successful left atrial posterior wall isolation (LAPWI) using only the cryoballoon (CB) is technically challenging for the treatment of atrial fibrillation (AF). This study aimed to evaluate the efficacy of the cross-over technique, wherein an overlapped ablation is performed by placing the CB from both directions in contact with the LAPW. METHODS: This was a single-center, retrospective, observational study of 194 consecutive patients with persistent atrial fibrillation (PerAF) who underwent a first-time procedure of pulmonary vein isolation (PVI) + PWI (108 patients) or PVI-only (86 patients) using the CB. The cross-over technique was applied in all LAPWI. RESULTS: For ablation of the LA roof and bottom, respectively, a mean of 8.6 ± 1.0 (right to left [R→L] 4.3 ± 1.1 and left to right [L→R] 4.3 ± 1.1) and 9.1 ± 1.2 (R→L 4.6 ± 1.6 and L→R 4.5 ± 1.2) CB applications were delivered. LAPW was successfully isolated solely using the CB in 99.1% of patients. Although the PVI + PWI group had significantly longer procedure time, no severe adverse events were observed in either group. During a median follow-up of 19 months, freedom from recurrence of all atrial tachyarrhythmias was achieved in 93.5% of the PVI + PWI group and 72.9% of the PVI-only group (p = .011). CONCLUSIONS: LAPWI performed solely with the CB using the cross-over technique is feasibly, safe, and was independently associated with a significantly higher freedom from recurrence of atrial tachyarrhythmias compared with PVI alone in patients with PerAF.

4.
J Endovasc Ther ; : 15266028231170119, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37128871

RESUMO

PURPOSE: The presence of severely calcified plaque remains problematic in endovascular therapy, and no specific endovascular treatment strategy has been established. Estimating plaque solidity before the procedure may help operators penetrate calcified plaque with a guide wire. The aim of this study was to establish a method of measuring plaque solidity with noncontrast computed tomography (CT). METHODS: This retrospective, single-center study included consecutive patients who, between October 2020 and July 2022, underwent noncontrast 5 mm and 1 mm CTs before endovascular therapy to penetrate calcified plaque with a wire in the common femoral, superficial femoral, and popliteal arteries. Three cross-sectional CT slices were selected. To target a calcified plaque lesion, the operator identified a region of interest, which corresponded to 24×24 pixels, and Hounsfield unit (HU) values of each pixel were displayed on the CT image. The average HU values and the ratio of number of pixels of lower values (130-599 HU) represented plaque solidity. We used the Mann-Whitney-Wilcoxon rank-sum test and the chi-square test to compare the solidity of plaques penetrated and not penetrated by the wire. RESULTS: We evaluated 108 images of 36 calcified plaque lesions (in 19 patients). The wire penetrated 28 lesions (77.8%) successfully. The average HU value was significantly lower in the lesions that the wire penetrated than in the others, in both the 5 mm CT slices (434.7±86.8 HU vs 554.3±112.7 HU, p=0.0174) and 1 mm slices (497.8±103.1 HU vs 593.5±114.5 HU, p=0.0381). The receiver operating curve revealed that 529.9 and 533.9 HU in the 5 and 1 mm slices, respectively, were the highest values at which wires could penetrate. Moreover, at the lesions that were penetrates successfully, the ratio of number of lower HU value pixels was significantly higher both in 5 mm slice CTs (74.7±13.4 vs 61.7±13.1%, p=0.0347) and 1 mm (68.7±11.8 vs 57.1±11.4%, p=0.0174). CONCLUSION: The use of noncontrast CT to evaluate plaque solidity was associated with successful wire penetration of calcified lesions in peripheral arteries. CLINICAL IMPACT: This study revealed an association between the wire penetration inside calcified plaque and plaque solidity estimated using non-contrasted computed tomography. The mean Hounsfield unit values of three cross-sections in calcified plaques were associated with the successful wire penetration. This wire penetration difficulty is associated with extended procedure time, excessive radiation exposure, usage of extra contrast agents, and increased medical costs. Therefore, estimating calcified plaque solidity before procedure enables us to choose effective and lean procedures. In addition, to predict the success of dilating calcified plaque from the inside is also beneficial when the operator wants to avoid extra scaffold implantation for target lesions.

5.
J Mater Sci Mater Med ; 31(11): 110, 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33165675

RESUMO

Ti-Zr alloys are expected to be novel biomaterials with low stress shielding owing to their lower Young's moduli than pure Ti. The drawback of metallic biomaterials is that their bone-bonding abilities are relatively low. NaOH and heat treatments have been performed to provide Ti-50Zr with apatite-forming ability in the body environment, which is essential for bone bonding. However, the systematic compositional dependence of apatite formation has not been revealed. In the present study, NaOH treatment of Ti-Zr alloys with various compositions and bone-bonding abilities was assessed in vitro by apatite formation in simulated body fluid (SBF). The corrosion current density in NaOH aqueous solution and the amount of Na incorporated into the surface tended to decrease with increasing Zr content. The apatite-forming ability of the treated alloy significantly decreased when the Zr content was ≥60 atom%. This phenomenon is attributed to the (1) low OH content on the surface, (2) low Na incorporation into the treated alloy surface, which enhances apatite formation, and (3) low ability of P adsorption to the Ti-Zr alloy in SBF following Ca adsorption to trigger apatite nucleation. Although the adhesion of the titanate/zirconate layer formed on the surfaces to the substrates increased as Zr content increased, the adhesion between the apatite and the substrate was still low.


Assuntos
Ligas/química , Apatitas/química , Materiais Biocompatíveis/química , Adsorção , Líquidos Corporais/química , Adesão Celular , Corrosão , Módulo de Elasticidade , Dureza , Temperatura Alta , Teste de Materiais , Metais/química , Microscopia Eletrônica de Varredura , Hidróxido de Sódio/química , Estresse Mecânico , Propriedades de Superfície , Difração de Raios X
6.
Proc Natl Acad Sci U S A ; 113(40): 11214-11219, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27647891

RESUMO

F1- and V1-ATPase are rotary molecular motors that convert chemical energy released upon ATP hydrolysis into torque to rotate a central rotor axle against the surrounding catalytic stator cylinder with high efficiency. How conformational change occurring in the stator is coupled to the rotary motion of the axle is the key unknown in the mechanism of rotary motors. Here, we generated chimeric motor proteins by inserting an exogenous rod protein, FliJ, into the stator ring of F1 or of V1 and tested the rotation properties of these chimeric motors. Both motors showed unidirectional and continuous rotation, despite no obvious homology in amino acid sequence between FliJ and the intrinsic rotor subunit of F1 or V1 These results showed that any residue-specific interactions between the stator and rotor are not a prerequisite for unidirectional rotation of both F1 and V1 The torque of chimeric motors estimated from viscous friction of the rotation probe against medium revealed that whereas the F1-FliJ chimera generates only 10% of WT F1, the V1-FliJ chimera generates torque comparable to that of V1 with the native axle protein that is structurally more similar to FliJ than the native rotor of F1 This suggests that the gross structural mismatch hinders smooth rotation of FliJ accompanied with the stator ring of F1.


Assuntos
Proteínas Motores Moleculares/química , Rotação , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Modelos Moleculares , Proteínas Motores Moleculares/metabolismo , Probabilidade , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , ATPases Translocadoras de Prótons/química , Proteínas Recombinantes/química , Alinhamento de Sequência , Fatores de Tempo , Torque , ATPases Vacuolares Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/metabolismo
7.
Heart Vessels ; 31(3): 397-401, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25471944

RESUMO

Warfarin is widely used to perform catheter ablation for atrial fibrillation (AF). Heparin is usually administered during this procedure to prevent thromboembolic events, while protamine is used to reduce the incidence of bleeding complications. The purpose of this study was to investigate the influence of heparin and protamine administration on the effects of warfarin and its safety. The subjects included 226 AF patients (206 males, 54.9 ± 9.1 years, paroxysmal/persistent AF: 118/108) undergoing AF ablation with the discontinuation of warfarin administration over 2 days. Heparin was administered to achieve an activated clotting time (ACT) above 300 s during the procedure. Several parameters of the coagulation status, including the prothrombin time international normalized ratio (PT-INR) and ACT values, measured immediately before and after protamine infusion were compared. The mean value of PT-INR prior to ablation was 1.9 ± 0.6. At the end of the procedure, the mean ACT and PT-INR values were 348.0 ± 52.9 and 2.9 ± 0.7, respectively. Following the infusion of 30 mg of protamine, both the ACT and PT-INR values significantly decreased, to 159.6 ± 31.0 (p < 0.0001) and 1.6 ± 0.3 (p < 0.0001), respectively. No cases of symptomatic cerebral infarction were observed, although femoral hematomas developed in 17 (7.5 %) of the patients without further consequence. The concomitant use of heparin augments the effect of warfarin. Meanwhile, protamine administration immediately reverses both the ACT and PT-INR, indicating the applicability of protamine for AF ablation in patients under the mixed administration of heparin and warfarin.


Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/terapia , Coagulação Sanguínea/efeitos dos fármacos , Ablação por Cateter , Heparina/administração & dosagem , Varfarina/administração & dosagem , Adulto , Idoso , Anticoagulantes/efeitos adversos , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Testes de Coagulação Sanguínea , Perda Sanguínea Cirúrgica/prevenção & controle , Ablação por Cateter/efeitos adversos , Esquema de Medicação , Monitoramento de Medicamentos/métodos , Feminino , Heparina/efeitos adversos , Antagonistas de Heparina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Hemorragia Pós-Operatória/induzido quimicamente , Hemorragia Pós-Operatória/prevenção & controle , Valor Preditivo dos Testes , Protaminas/administração & dosagem , Fatores de Risco , Tromboembolia/etiologia , Tromboembolia/prevenção & controle , Fatores de Tempo , Resultado do Tratamento , Varfarina/efeitos adversos
8.
Nat Genet ; 39(9): 1140-4, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17694055

RESUMO

Surveys of protein-coding sequences for evidence of positive selection in humans or chimpanzees have flagged only a few genes known to function in neural or nutritional processes, despite pronounced differences between humans and chimpanzees in behavior, cognition and diet. It may be that most such differences are due to changes in gene regulation rather than protein structure. Here, we present the first survey of promoter (5'-flanking) regions, which are rich in cis-regulatory sequences, for evidence of positive selection in humans. Our results indicate that positive selection has targeted the regulation of many genes known to be involved in neural development and function, both in the brain and elsewhere in the nervous system, and in nutrition, particularly in glucose metabolism.


Assuntos
Evolução Molecular , Sistema Nervoso/metabolismo , Nutrigenômica , Regiões Promotoras Genéticas/genética , Seleção Genética , Região 5'-Flanqueadora , Animais , Biologia Computacional/métodos , Metabolismo Energético/genética , Regulação da Expressão Gênica no Desenvolvimento , Genoma Humano , Humanos , Modelos Genéticos , Sistema Nervoso/embriologia , Sistema Nervoso/crescimento & desenvolvimento , Pan troglodytes
9.
Int Heart J ; 57(2): 150-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26973257

RESUMO

Few studies have investigated the clinical outcomes of rotational atherectomy (RA) prior to and during the drugeluting stent (DES) era. The goal of this study was to assess the long-term outcome after RA followed by DES and bare metal stent (BMS) implantation in complex calcified coronary lesions and to compare the outcomes among various DESs.This was a single center retrospective observational study. Consecutive 406 patients who underwent elective RA followed by BMS or DES implantation at our institution from 2001 to 2011 were included. This study compared the long-term outcomes after treatment with RA among BMS and 3 different DESs (sirolimus-eluting stent, paclitaxel-eluting stent, and everolimus-eluting stent) implantation.The mean follow-up period was 4.6 years. Patients with DES were older and exhibited more vessel disease, longer lesion length, and smaller vessel size. Patients with BMS had a significantly higher rate of target lesion revascularization, restenosis, and larger late lumen loss than those with DES. Composite events including mortality, ACS, and target vessel revascularization were significantly higher in the BMS-RA group than in the DES-RA group. After adjustment, BMS remained an independent predictor of MACE and ACS plus death in patients treated with RA. However, there were no significant differences in late lumen loss, restenosis rate, and MACE among the 3 DES.The combination of DES-RA has a favorable effect in both the angiographic and clinical outcomes compared with BMS-RA. However, no significant differences in late loss and events rates were observed among the 3 DES groups.


Assuntos
Aterectomia Coronária , Angiografia Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Stents Farmacológicos , Oclusão de Enxerto Vascular/epidemiologia , Imunossupressores/farmacologia , Intervenção Coronária Percutânea/métodos , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Everolimo/farmacologia , Feminino , Seguimentos , Oclusão de Enxerto Vascular/diagnóstico por imagem , Humanos , Incidência , Japão/epidemiologia , Masculino , Paclitaxel/farmacologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Sirolimo/farmacologia , Fatores de Tempo , Resultado do Tratamento
10.
J Biol Chem ; 289(1): 403-12, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24247239

RESUMO

Reduction of ATP hydrolysis activity of vacuolar-type ATPase/synthase (V0V1) as a result of ADP inhibition occurs as part of the normal mechanism of V0V1 of Thermus thermophilus but not V0V1 of Enterococcus hirae or eukaryotes. To investigate the molecular basis for this difference, domain-swapped chimeric V1 consisting of both T. thermophilus and E. hirae enzymes were generated, and their function was analyzed. The data showed that the interaction between the nucleotide binding and C-terminal domains of the catalytic A subunit from E. hirae V1 is central to increasing binding affinity of the chimeric V1 for phosphate, resulting in reduction of the ADP inhibition. These findings together with a comparison of the crystal structures of T. thermophilus V1 with E. hirae V1 strongly suggest that the A subunit adopts a conformation in T. thermophilus V1 different from that in E. hirae V1. This key difference results in ADP inhibition of T. thermophilus V1 by abolishing the binding affinity for phosphate during ATP hydrolysis.


Assuntos
Difosfato de Adenosina/química , Trifosfato de Adenosina/química , Proteínas de Bactérias/química , Enterococcus/enzimologia , Thermus thermophilus/enzimologia , ATPases Vacuolares Próton-Translocadoras/química , Difosfato de Adenosina/genética , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/genética , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Enterococcus/genética , Estrutura Terciária de Proteína , Subunidades Proteicas , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Especificidade da Espécie , Thermus thermophilus/genética , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo
11.
PLoS Comput Biol ; 10(8): e1003771, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25144359

RESUMO

Changes in cis-regulatory element composition that result in novel patterns of gene expression are thought to be a major contributor to the evolution of lineage-specific traits. Although transcription factor binding events show substantial variation across species, most computational approaches to study regulatory elements focus primarily upon highly conserved sites, and rely heavily upon multiple sequence alignments. However, sequence conservation based approaches have limited ability to detect lineage-specific elements that could contribute to species-specific traits. In this paper, we describe a novel framework that utilizes a birth-death model to trace the evolution of lineage-specific binding sites without relying on detailed base-by-base cross-species alignments. Our model was applied to analyze the evolution of binding sites based on the ChIP-seq data for six transcription factors (GATA1, SOX2, CTCF, MYC, MAX, ETS1) along the lineage toward human after human-mouse common ancestor. We estimate that a substantial fraction of binding sites (∼58-79% for each factor) in humans have origins since the divergence with mouse. Over 15% of all binding sites are unique to hominids. Such elements are often enriched near genes associated with specific pathways, and harbor more common SNPs than older binding sites in the human genome. These results support the ability of our method to identify lineage-specific regulatory elements and help understand their roles in shaping variation in gene regulation across species.


Assuntos
Sítios de Ligação/genética , Evolução Molecular , Modelos Genéticos , Fatores de Transcrição/genética , Animais , Sequência de Bases , Biologia Computacional , Humanos , Camundongos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Primatas , Alinhamento de Sequência , Especificidade da Espécie
12.
J Biol Chem ; 288(1): 619-23, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23155048

RESUMO

V(1)-ATPase is a rotary motor protein that rotates the central shaft in a counterclockwise direction hydrolyzing ATP. Although the ATP-binding process is suggested to be the most critical reaction step for torque generation in F(1)-ATPase (the closest relative of V(1)-ATPase evolutionarily), the role of ATP binding for V(1)-ATPase in torque generation has remained unclear. In the present study, we performed single-molecule manipulation experiments on V(1)-ATPase from Thermus thermophilus to investigate how the ATP-binding process is modulated upon rotation of the rotary shaft. When V(1)-ATPase showed an ATP-waiting pause, it was stalled at a target angle and then released. Based on the response of the V(1)-ATPase released, the ATP-binding probability was determined at individual stall angles. It was observed that the rate constant of ATP binding (k(on)) was exponentially accelerated with forward rotation, whereas the rate constant of ATP release (k(off)) was exponentially reduced. The angle dependence of the k(off) of V(1)-ATPase was significantly smaller than that of F(1)-ATPase, suggesting that the ATP-binding process is not the major torque-generating step in V(1)-ATPase. When V(1)-ATPase was stalled at the mean binding angle to restrict rotary Brownian motion, k(on) was evidently slower than that determined from free rotation, showing the reaction rate enhancement by conformational fluctuation. It was also suggested that shaft of V(1)-ATPase should be rotated at least 277° in a clockwise direction for efficient release of ATP under ATP-synthesis conditions.


Assuntos
ATPases Vacuolares Próton-Translocadoras/química , Trifosfato de Adenosina/química , Bioquímica/métodos , Biofísica/métodos , Hidrólise , Cinética , Proteínas Motores Moleculares/metabolismo , Ligação Proteica , Estresse Mecânico , Thermus thermophilus/metabolismo , Fatores de Tempo
13.
Eur Biophys J ; 43(8-9): 415-22, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25012687

RESUMO

Vacuolar-type H(+)-pumping ATPases (V-ATPases) perform remarkably diverse functions in eukaryotic organisms. They are present in the membranes of many organelles and regulate the pH of several intracellular compartments. A family of V-ATPases is also present in the plasma membranes of some bacteria. Such V-ATPases function as ATP-synthases. Each V-ATPase is composed of a water-soluble domain (V1) and a membrane-embedded domain (Vo). The ATP-driven rotary unit, V[Formula: see text], is composed of A, B, D, and F subunits. The rotary shaft (the DF subcomplex) rotates in the central cavity of the A3B3-ring (the catalytic hexamer ring). The D-subunit, which has a coiled-coil domain, penetrates into the ring, while the F-subunit is a globular-shaped domain protruding from the ring. The minimal ATP-driven rotary unit of V[Formula: see text] is comprised of the A3B3D subunits, and we therefore investigated how the absence of the globular-shaped F-subunit affects the rotary torque generation of V[Formula: see text]. Using a single-molecule technique, we observed the motion of the rotary motors. To obtain the torque values, we then analyzed the measured motion trajectories based on the fluctuation theorem, which states that the law of entropy production in non-equilibrium conditions and has been suggested as a novel and effective method for measuring torque. The measured torque of A3B3D was half that of the wild-type V1, and full torque was recovered in the mutant V1, in which the F-subunit was genetically fused with the D-subunit, indicating that the globular-shaped F-subunit reinforces torque generation in V1.


Assuntos
Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Torque , ATPases Vacuolares Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/metabolismo , Evolução Molecular , Modelos Moleculares , Estrutura Terciária de Proteína , Rotação
14.
Europace ; 16(2): 208-13, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23751930

RESUMO

AIMS: Although patients with paroxysmal atrial fibrillation (AF) and prolonged sinus pauses [tachycardia-bradycardia syndrome (TBS)] are generally treated by permanent pacemaker, catheter ablation has been reported to be a curative therapy for TBS without pacemaker implantation. The purpose of this study was to define the potential role of successful ablation in patients with TBS. METHODS AND RESULTS: Of 280 paroxysmal AF patients undergoing ablation, 37 TBS patients with both AF and symptomatic sinus pauses (age: 62 ± 8 years; mean maximum pauses: 6 ± 2 s) were analysed. During the 5.8 ± 1.2 years (range: 5-8.7 years) follow-up, both tachyarrhythmia and bradycardia were eliminated by a single procedure in 19 of 37 (51%) patients. Repeat procedures were performed in 14 of 18 patients with tachyarrhythmia recurrence (second: 12 and third: 2 patients). During the repeat procedure, 79% (45 of 57) of previously isolated pulmonary veins (PVs) were reconnected to the left atrium. Pulmonary vein tachycardia initiating the AF was found in 46% (17 of 37) and 43% (6 of 14) of patients during the initial and second procedure, respectively. Finally, 32 (86%) patients remained free from AF after the last procedure. Three patients (8%) required pacemaker implantation, one for the gradual progression of sinus dysfunction during a period of 6.5 years and the others for recurrence of TBS 3.5 and 5.5 years after ablation, respectively. CONCLUSION: Catheter ablation can eliminate both AF and prolonged sinus pauses in the majority of TBS patients. Nevertheless, such patients should be continuously followed-up, because gradual progression of sinus node dysfunction can occur after a long period of time.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Sistema de Condução Cardíaco/cirurgia , Frequência Cardíaca , Parada Sinusal Cardíaca/cirurgia , Adulto , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Ablação por Cateter/efeitos adversos , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Síndrome do Nó Sinusal/etiologia , Síndrome do Nó Sinusal/fisiopatologia , Síndrome do Nó Sinusal/terapia , Parada Sinusal Cardíaca/diagnóstico , Parada Sinusal Cardíaca/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
15.
J Biol Chem ; 287(29): 24597-603, 2012 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-22582389

RESUMO

Vacuolar-type rotary H(+)-ATPase/synthase (V(o)V(1)) from Thermus thermophilus, composed of nine subunits, A, B, D, F, C, E, G, I, and L, has been reconstituted from individually isolated V(1) (A(3)B(3)D(1)F(1)) and V(o) (C(1)E(2)G(2)I(1)L(12)) subcomplexes in vitro. A(3)B(3)D and A(3)B(3) also reconstituted with V(o), resulting in a holoenzyme-like complexes. However, A(3)B(3)D-V(o) and A(3)B(3)-V(o) did not show ATP synthesis and dicyclohexylcarbodiimide-sensitive ATPase activity. The reconstitution process was monitored in real time by fluorescence resonance energy transfer (FRET) between an acceptor dye attached to subunit F or D in V(1) or A(3)B(3)D and a donor dye attached to subunit C in V(o). The estimated dissociation constants K(d) for V(o)V(1) and A(3)B(3)D-V(o) were ∼0.3 and ∼1 nm at 25 °C, respectively. These results suggest that the A(3)B(3) domain tightly associated with the two EG peripheral stalks of V(o), even in the absence of the central shaft subunits. In addition, F subunit is essential for coupling of ATP hydrolysis and proton translocation and has a key role in the stability of whole complex. However, the contribution of the F subunit to the association of A(3)B(3) with V(o) is much lower than that of the EG peripheral stalks.


Assuntos
Proteínas de Bactérias/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Thermus thermophilus/enzimologia , ATPases Vacuolares Próton-Translocadoras/metabolismo , Proteínas de Bactérias/química , Transferência Ressonante de Energia de Fluorescência , ATPases Mitocondriais Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/química
16.
J Biol Chem ; 287(34): 28327-35, 2012 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-22736762

RESUMO

V(1)-ATPase, the hydrophilic V-ATPase domain, is a rotary motor fueled by ATP hydrolysis. Here, we found that Thermus thermophilus V(1)-ATPase shows two types of inhibitory pauses interrupting continuous rotation: a short pause (SP, 4.2 s) that occurred frequently during rotation, and a long inhibitory pause (LP, >30 min) that terminated all active rotations. Both pauses occurred at the same angle for ATP binding and hydrolysis. Kinetic analysis revealed that the time constants of inactivation into and activation from the SP were too short to represent biochemically predicted ADP inhibition, suggesting that SP is a newly identified inhibitory state of V(1)-ATPase. The time constant of inactivation into LP was 17 min, consistent with one of the two time constants governing the inactivation process observed in bulk ATPase assay. When forcibly rotated in the forward direction, V(1) in LP resumed active rotation. Solution ADP suppressed the probability of mechanical activation, suggesting that mechanical rotation enhanced inhibitory ADP release. These features were highly consistent with mechanical activation of ADP-inhibited F(1), suggesting that LP represents the ADP-inhibited state of V(1)-ATPase. Mechanical activation largely depended on the direction and angular displacement of forced rotation, implying that V(1)-ATPase rotation modulates the off rate of ADP.


Assuntos
Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/metabolismo , Thermus thermophilus/enzimologia , Difosfato de Adenosina/genética , Difosfato de Adenosina/metabolismo , Adenosina Trifosfatases/genética , Trifosfato de Adenosina/genética , Proteínas de Bactérias/genética , Ativação Enzimática/fisiologia , Hidrólise , Thermus thermophilus/genética
17.
EMBO J ; 28(23): 3771-9, 2009 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-19893485

RESUMO

Vacuolar-type ATPases (V-ATPases) exist in various cellular membranes of many organisms to regulate physiological processes by controlling the acidic environment. Here, we have determined the crystal structure of the A(3)B(3) subcomplex of V-ATPase at 2.8 A resolution. The overall construction of the A(3)B(3) subcomplex is significantly different from that of the alpha(3)beta(3) sub-domain in F(o)F(1)-ATP synthase, because of the presence of a protruding 'bulge' domain feature in the catalytic A subunits. The A(3)B(3) subcomplex structure provides the first molecular insight at the catalytic and non-catalytic interfaces, which was not possible in the structures of the separate subunits alone. Specifically, in the non-catalytic interface, the B subunit seems to be incapable of binding ATP, which is a marked difference from the situation indicated by the structure of the F(o)F(1)-ATP synthase. In the catalytic interface, our mutational analysis, on the basis of the A(3)B(3) structure, has highlighted the presence of a cluster composed of key hydrophobic residues, which are essential for ATP hydrolysis by V-ATPases.


Assuntos
Subunidades Proteicas/química , Thermus thermophilus/enzimologia , ATPases Vacuolares Próton-Translocadoras/química , Trifosfato de Adenosina/química , Bacillus/enzimologia , Bacillus/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico/genética , Cristalização , Cristalografia por Raios X , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Mutagênese Sítio-Dirigida , Estrutura Terciária de Proteína/genética , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Thermus thermophilus/genética , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo
18.
Anal Chem ; 85(16): 7889-96, 2013 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-23875533

RESUMO

Adenosine 5'-triphosphate (ATP) is the major energy currency of all living organisms. Despite its important functions, the spatiotemporal dynamics of ATP levels inside living multicellular organisms is unclear. In this study, we modified the genetically encoded Förster resonance energy transfer (FRET)-based ATP biosensor ATeam to optimize its affinity at low temperatures. This new biosensor, AT1.03NL, detected ATP changes inside Drosophila S2 cells more sensitively than the original biosensor did, at 25 °C. By expressing AT1.03NL in Drosophila melanogaster and Caenorhabditis elegans, we succeeded in imaging the in vivo ATP dynamics of these model animals at single-cell resolution.


Assuntos
Trifosfato de Adenosina/metabolismo , Técnicas Biossensoriais , Caenorhabditis elegans/metabolismo , Temperatura Baixa , Drosophila melanogaster/metabolismo , Corantes Fluorescentes/metabolismo , Animais , Animais Geneticamente Modificados , Transferência Ressonante de Energia de Fluorescência
19.
Circ J ; 77(2): 456-61, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23075764

RESUMO

BACKGROUND: Red blood cell distribution width (RDW) is a novel prognostic marker that reflects oxidative stress and chronic inflammation in patients with cardiovascular disease. Diabetes mellitus increases oxidative stress and vascular inflammation, which accelerate atherosclerosis. However, the relationship between RDW and long-term outcome in diabetic patients with coronary artery disease (CAD) is unclear. METHODS AND RESULTS: Subjects comprised 560 consecutive diabetic patients (mean age, 66.6 years; male, 80%) with stable CAD who had undergone elective percutaneous coronary intervention (PCI). Patients were divided into 2 groups according to median RDW at baseline (13.1%): a high RDW group (mean RDW, 14.0%; interquartile range, 13.3-14.2%); and a low RDW group (mean RDW, 12.6%; interquartile range, 12.4-12.9%). All-cause mortality rates were compared between groups. Mean duration of follow up was 3.9 years. Patients with high RDW were more likely to be older, show dyslipidemia and have a lower ejection fraction and decreased hemoglobin level. Twenty-nine patients (5.2%) died during follow up. The cumulative incidence of all-cause death was significantly higher in the high RDW group than in the low RDW group (log-rank P=0.0015). Multivariate analysis identified high RDW as being associated with all-cause mortality (hazard ratio, 2.56; 95% confidence interval, 1.12-6.62; P=0.025). CONCLUSIONS: Increased RDW was significantly associated with increased long-term all-cause mortality in diabetic patients after PCI.


Assuntos
Angioplastia Coronária com Balão/mortalidade , Doença da Artéria Coronariana , Diabetes Mellitus/sangue , Diabetes Mellitus/mortalidade , Índices de Eritrócitos , Distribuição por Idade , Idoso , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/terapia , Dislipidemias/sangue , Dislipidemias/mortalidade , Eritrócitos/patologia , Feminino , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Infarto do Miocárdio/sangue , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Estresse Oxidativo , Prognóstico , Resultado do Tratamento , Vasculite/sangue , Vasculite/mortalidade
20.
Front Mol Biosci ; 10: 1176114, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37168257

RESUMO

V/A-ATPase is a rotary molecular motor protein that produces ATP through the rotation of its central rotor. The soluble part of this protein, the V1 domain, rotates upon ATP hydrolysis. However, the mechanism by which ATP hydrolysis in the V1 domain couples with the mechanical rotation of the rotor is still unclear. Cryo-EM snapshot analysis of V/A-ATPase indicated that three independent and simultaneous catalytic events occurred at the three catalytic dimers (ABopen, ABsemi, and ABclosed), leading to a 120° rotation of the central rotor. Besides the closing motion caused by ATP bound to ABopen, the hydrolysis of ATP bound to ABsemi drives the 120° step. Our recent time-resolved cryo-EM snapshot analysis provides further evidence for this model. This review aimed to provide a comprehensive overview of the structure and function of V/A-ATPase from a thermophilic bacterium, one of the most well-studied rotary ATPases to date.

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