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1.
Health Expect ; 26(4): 1738-1745, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37254844

RESUMO

INTRODUCTION: Numerous frameworks for defining and supporting co-created research exist. The practicalities of designing and conducting co-created research are clearly important, yet the utility of these frameworks and their operationalisation within local contexts and involving a diversity of stakeholders and interests are currently not well-researched. METHODS: Using an instrumental case study approach, we examined the utility of a published systematic framework designed to improve clarity about co-creation as a concept and approach. The framework is explored based on the first two processes that correspond to our own work to date: co-ideation and co-design. RESULTS: Our study showed that diverse stakeholders bring challenges regarding research priorities, methods, language and the distribution of power within co-creation processes. Co-creation activities were incremental, adaptable, responsive and made best use of established relationships, structures and collective leadership to meet the competing demands of funders and human research ethics committees, while ensuring the meaningful participation of multiple stakeholders. CONCLUSION: The findings highlight the iterative, fluid and deeply relational nature of co-created research. Rather than seeking to categorise these processes, we argue that the social relations of research production that provide the structures within which all co-created knowledge is generated are more important drivers of effective knowledge mobilisation and implementation. Thus, close attention to these social relations is needed in co-created research. PATIENT OR PUBLIC CONTRIBUTION: People with lived experience of emotional distress and/or suicidal crisis, including academic researchers, service and peer workers, carers and advocates were involved in the co-ideation and co-design of this research. All authors identify as people with lived experience, from both academic and nonresearch backgrounds.


Assuntos
Idioma , Pesquisa , Humanos
2.
PLoS One ; 17(10): e0272483, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36190989

RESUMO

INTRODUCTION: Safe spaces are an alternative to emergency departments, which are often unable to provide optimum care for people experiencing emotional distress and/or suicidal crisis. At present, there are several different safe space models being trialled in Australia. However, research examining the effectiveness of safe space models, especially in community settings, is rare. In this paper, we present a protocol for a study in which we will investigate the implementation, effectiveness, and sustainability of safe space models as genuine alternatives for people who might usually present to the emergency department or choose not to access help due to past negative experiences. MATERIAL AND METHODS: We will use a mixed methods, co-designed study design, conducted according to the principles of community-based participatory research to obtain deep insights into the benefits of different safe space models, potential challenges, and facilitators of effective practice. We developed the study plan and evaluation framework using the RE-AIM framework, and this will be used to assess key outcomes related to reach, effectiveness, adoption, implementation, and maintenance. Data collection will comprise quantitative measures on access, use, satisfaction, (cost) effectiveness, distress, and suicidal ideation; and qualitative assessments of service implementation, experience, feasibility, acceptability, community awareness, and the fidelity of the models to service co-design. Data will be collected and analysed concurrently throughout the trial period of the initiatives. DISCUSSION: This study will enable an extensive investigation of safe spaces that will inform local delivery and provide a broader understanding of the key features of safe spaces as acceptable and effective alternatives to hospital-based care for people experiencing emotional distress and/or suicidal crisis. This study will also contribute to a growing body of research on the role and benefits of peer support and provide critical new knowledge on the successes and challenges of service co-design to inform future practice.


Assuntos
Angústia Psicológica , Ideação Suicida , Serviço Hospitalar de Emergência , Humanos , Projetos de Pesquisa , Pesquisa Translacional Biomédica
3.
FEBS J ; 287(13): 2647-2663, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32239637

RESUMO

Apoptosis is a highly regulated form of cell death that is required for many homeostatic and pathological processes. Recently, alternative cell death pathways have emerged whose regulation is dependent on proteins with canonical functions in apoptosis. Dysregulation of apoptotic signaling frequently underlies the pathogenesis of many cancers, reinforcing the need to develop therapies that initiate alternative cell death processes. This review outlines the convergence points between apoptosis and other death pathways with the purpose of identifying novel strategies for the treatment of apoptosis-refractory cancers. Apoptosis proteins can play key roles in the initiation, regulation, and execution of nonapoptotic death processes that include necroptosis, autophagy, pyroptosis, mPTP-mediated necrosis, and ferroptosis. Notably, recent evidence illustrates that dying cells can exhibit biochemical and molecular characteristics of more than one different type of regulated cell death. Thus, this review highlights the amazing complexity and interconnectivity of cell death processes and also raises the idea that a top-to-bottom approach to describing cell death mechanisms may be inadequate for fully understanding the means by which cells die.


Assuntos
Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Animais , Autofagia , Humanos , Neoplasias/metabolismo , Transdução de Sinais
4.
Mol Cell ; 75(6): 1087-1089, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31539505

RESUMO

The role of hormones in triggering cell death has been controversial. In this issue of Molecular Cell, Li et al. (2019) have defined a molecular pathway where an unexpected estrogen receptor, phosphodiesterase 3A, allows its partner Schlafen-12 to inhibit survival pathways, ultimately leading to apoptosis.


Assuntos
Apoptose , Estrogênios , Receptores de Estrogênio
5.
Methods Mol Biol ; 1877: 1-21, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30535995

RESUMO

BCL-2 family proteins interact in a network that regulates apoptosis. The BH3 amino acid sequence motif serves to bind together this conglomerate protein family, both literally and figuratively. BH3 motifs are present in antiapoptotic and proapoptotic BCL-2 homologs, and in a separate group of unrelated BH3-only proteins often appended to the BCL-2 family. BH3-containing helices mediate many of their physical interactions to determine cell death versus survival, leading to the development of BH3 mimetics as therapeutics. Here we provide an overview of BCL-2 family interactions, their relevance in health and disease, and the progress toward regulating their interactions therapeutically.


Assuntos
Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Motivos de Aminoácidos/fisiologia , Aminoácidos/metabolismo , Animais , Apoptose/fisiologia , Humanos
6.
Ann Neurol ; 84(5): 766-780, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30295347

RESUMO

OBJECTIVE: Several small case series identified KCTD7 mutations in patients with a rare autosomal recessive disorder designated progressive myoclonic epilepsy (EPM3) and neuronal ceroid lipofuscinosis (CLN14). Despite the name KCTD (potassium channel tetramerization domain), KCTD protein family members lack predicted channel domains. We sought to translate insight gained from yeast studies to uncover disease mechanisms associated with deficiencies in KCTD7 of unknown function. METHODS: Novel KCTD7 variants in new and published patients were assessed for disease causality using genetic analyses, cell-based functional assays of patient fibroblasts and knockout yeast, and electron microscopy of patient samples. RESULTS: Patients with KCTD7 mutations can exhibit movement disorders or developmental regression before seizure onset, and are distinguished from similar disorders by an earlier age of onset. Although most published KCTD7 patient variants were excluded from a genome sequence database of normal human variations, most newly identified patient variants are present in this database, potentially challenging disease causality. However, genetic analysis and impaired biochemical interactions with cullin 3 support a causal role for patient KCTD7 variants, suggesting deleterious alleles of KCTD7 and other rare disease variants may be underestimated. Both patient-derived fibroblasts and yeast lacking Whi2 with sequence similarity to KCTD7 have impaired autophagy consistent with brain pathology. INTERPRETATION: Biallelic KCTD7 mutations define a neurodegenerative disorder with lipofuscin and lipid droplet accumulation but without defining features of neuronal ceroid lipofuscinosis or lysosomal storage disorders. KCTD7 deficiency appears to cause an underlying autophagy-lysosome defect conserved in yeast, thereby assigning a biological role for KCTD7. Ann Neurol 2018;84:774-788.


Assuntos
Autofagia/genética , Lisossomos/genética , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Canais de Potássio/deficiência , Idade de Início , Pré-Escolar , Feminino , Humanos , Lactente , Lisossomos/patologia , Masculino , Mutação , Linhagem , Canais de Potássio/genética , Proteínas de Saccharomyces cerevisiae/genética
7.
BMJ Open Respir Res ; 5(1): e000360, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30622718

RESUMO

INTRODUCTION: Patients with progressive idiopathic fibrotic interstitial lung disease (ILD), such as those with idiopathic pulmonary fibrosis (IPF), can have an aggressive disease course, with a median survival of only 3-5 years from diagnosis. The palliative care needs of these patients are often unmet. There are calls for new models of care, whereby the patient's usual respiratory clinician remains central to the integration of palliative care principles and practices into their patient's management, but the optimal model of service delivery has yet to be determined. METHODS: We developed a novel, collaborative, multidisciplinary team (MDT) meeting between our palliative care, psychology and ILD teams with the principal aim of integrating specialist care to ensure the needs of persons with ILD, and their caregivers were identified and met by referral to the appropriate service. The objective of this study was to assess the effectiveness of this novel MDT meeting on the assessment of a patient's palliative care needs. RESULTS: Significant increases in advance care planning discussions were observed, in conjunction with increased referrals to community courses and teams, following introduction of this novel MDT. CONCLUSIONS: Our results suggest that our collaborative MDT is an effective platform to address patients' unmet palliative care needs. Further work is required to explore the effect of our model on achieving the preferred place of death and reductions in unplanned hospital admissions.

8.
Nucleic Acids Res ; 46(1): 473-484, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29165717

RESUMO

Bacterial biofilms are a complex architecture of cells that grow on moist interfaces, and are held together by a molecular glue of extracellular proteins, sugars and nucleic acids. Biofilms are particularly problematic in human healthcare as they can coat medical implants and are thus a potential source of disease. The enzymatic dispersal of biofilms is increasingly being developed as a new strategy to treat this problem. Here, we have characterized NucB, a biofilm-dispersing nuclease from a marine strain of Bacillus licheniformis, and present its crystal structure together with the biochemistry and a mutational analysis required to confirm its active site. Taken together, these data support the categorization of NucB into a unique subfamily of the ßßα metal-dependent non-specific endonucleases. Understanding the structure and function of NucB will facilitate its future development into an anti-biofilm therapeutic agent.


Assuntos
Bacillus licheniformis/fisiologia , Proteínas de Bactérias/química , Biofilmes/crescimento & desenvolvimento , Desoxirribonucleases/química , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , DNA/genética , DNA/metabolismo , Desoxirribonucleases/genética , Desoxirribonucleases/metabolismo , Modelos Moleculares , Conformação Proteica
9.
BMJ Support Palliat Care ; 8(3): 340-346, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28667087

RESUMO

OBJECTIVES: Palliative care is underused in non-malignant respiratory diseases, including interstitial lung diseases (ILDs). We investigated current practices around palliative and supportive care and explored the impact of a supportive care decision aid tool. METHODS: This was a single centre study in a UK ILD centre. Retrospective analysis of hospice referrals and patients with idiopathic pulmonary fibrosis (IPF) under the Bristol ILD (BILD) service were used to identify unmet palliative and supportive care needs. Using quality improvement methodology, we explored the impact of a supportive care decision aid on clinician behaviours for patients with ILD. RESULTS: 108 patients with ILD were referred for hospice care between 2010 and 2015, representing 0.15% of all referrals, compared with a population prevalence of IPF of 0.9%. The median interval between referral and death was 124 days.Records were reviewed for 64 deceased and 89 living patients with IPF seen on July-December 2014. The decision aid was prospectively assessed with 73 patients. The deceased patients had greater markers of severity. There were no other differences between the groups.After introduction, the decision aid tool was completed for 49.3% of patients and resulted in significant increases in documented discussion of referral to palliative care (11.2%vs53.6%, p<0.01) and end-of-life discussions (15.7%vs91.8%, p<0.01). Tool completion led to an increase in referral for palliative care (2.7%vs16.7%, p<0.01). CONCLUSION: Palliative care services are underused in ILD and a supportive care decision aid can prompt consideration of palliative and supportive care needs.


Assuntos
Fibrose Pulmonar Idiopática/terapia , Doenças Pulmonares Intersticiais/terapia , Cuidados Paliativos/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Encaminhamento e Consulta , Idoso , Tomada de Decisão Clínica , Técnicas de Apoio para a Decisão , Feminino , Humanos , Fibrose Pulmonar Idiopática/epidemiologia , Doenças Pulmonares Intersticiais/epidemiologia , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Prevalência , Estudos Retrospectivos , Reino Unido/epidemiologia
10.
Arthritis Rheumatol ; 69(8): 1601-1611, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28464560

RESUMO

OBJECTIVE: To assess the ability of matriptase, a type II transmembrane serine proteinase, to promote aggrecan loss from the cartilage of patients with osteoarthritis (OA) and to determine whether its inhibition can prevent aggrecan loss and cartilage damage in experimental OA. METHODS: Aggrecan release from human OA cartilage explants and human stem cell-derived cartilage discs was evaluated, and cartilage-conditioned media were used for Western blotting. Gene expression was analyzed by real-time polymerase chain reaction. Murine OA was induced by surgical destabilization of the medial meniscus, and matriptase inhibitors were administered via osmotic minipump or intraarticular injection. Cartilage damage was scored histologically and aggrecan cleavage was visualized immunohistochemically using specific neoepitope antibodies. RESULTS: The addition of soluble recombinant matriptase promoted a time-dependent release of aggrecan (and collagen) from OA cartilage, which was sensitive to metalloproteinase inhibition and protease-activated receptor 2 antagonism. Although engineered human (normal) cartilage discs failed to release aggrecan following matriptase addition, both matrix metalloproteinase- and aggrecanase-mediated cleavages of aggrecan were detected in human OA cartilage. Additionally, while matriptase did not directly degrade aggrecan, it promoted the accumulation of low-density lipoprotein receptor-related protein 1 (LRP-1) in conditioned media of the OA cartilage explants. Matriptase inhibition via neutralizing antibody or small molecule inhibitor significantly reduced cartilage damage scores in murine OA, which was associated with reduced generation of metalloproteinase-mediated aggrecan cleavage. CONCLUSION: Matriptase potently induces the release of metalloproteinase-generated aggrecan fragments as well as soluble LRP-1 from OA cartilage. Therapeutic targeting of matriptase proteolytic activity reduces metalloproteinase activity, further suggesting that this serine proteinase may have potential as a disease-modifying therapy in OA.


Assuntos
Agrecanas/efeitos dos fármacos , Cartilagem Articular/efeitos dos fármacos , Osteoartrite do Joelho/metabolismo , Serina Endopeptidases/farmacologia , Proteína ADAMTS4/efeitos dos fármacos , Proteína ADAMTS4/metabolismo , Proteína ADAMTS5/efeitos dos fármacos , Proteína ADAMTS5/metabolismo , Idoso , Idoso de 80 Anos ou mais , Agrecanas/metabolismo , Animais , Anticorpos Neutralizantes/farmacologia , Western Blotting , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Endopeptidases/efeitos dos fármacos , Endopeptidases/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/efeitos dos fármacos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Masculino , Metaloproteinases da Matriz/efeitos dos fármacos , Metaloproteinases da Matriz/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Meniscos Tibiais/cirurgia , Camundongos , Pessoa de Meia-Idade , Osteoartrite do Joelho/patologia , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/farmacologia , Serina Endopeptidases/metabolismo
11.
Neurochem Int ; 109: 141-161, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28461171

RESUMO

The morphology of a population of mitochondria is the result of several interacting dynamical phenomena, including fission, fusion, movement, elimination and biogenesis. Each of these phenomena is controlled by underlying molecular machinery, and when defective can cause disease. New understanding of the relationships between form and function of mitochondria in health and disease is beginning to be unraveled on several fronts. Studies in mammals and model organisms have revealed that mitochondrial morphology, dynamics and function appear to be subject to regulation by the same proteins that regulate apoptotic cell death. One protein family that influences mitochondrial dynamics in both healthy and dying cells is the Bcl-2 protein family. Connecting mitochondrial dynamics with life-death pathway forks may arise from the intersection of Bcl-2 family proteins with the proteins and lipids that determine mitochondrial shape and function. Bcl-2 family proteins also have multifaceted influences on cells and mitochondria, including calcium handling, autophagy and energetics, as well as the subcellular localization of mitochondrial organelles to neuronal synapses. The remarkable range of physical or functional interactions by Bcl-2 family proteins is challenging to assimilate into a cohesive understanding. Most of their effects may be distinct from their direct roles in apoptotic cell death and are particularly apparent in the nervous system. Dual roles in mitochondrial dynamics and cell death extend beyond BCL-2 family proteins. In this review, we discuss many processes that govern mitochondrial structure and function in health and disease, and how Bcl-2 family proteins integrate into some of these processes.


Assuntos
Mitocôndrias/metabolismo , Dinâmica Mitocondrial/fisiologia , Membranas Mitocondriais/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Humanos
12.
Biochem J ; 458(3): 547-57, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24392963

RESUMO

DHQ2 (type II dehydroquinase), which is an essential enzyme in Helicobacter pylori and Mycobacterium tuberculosis and does not have any counterpart in humans, is recognized to be an attractive target for the development of new antibacterial agents. Computational and biochemical studies that help understand in atomic detail the catalytic mechanism of these bacterial enzymes are reported in the present paper. A previously unknown key role of certain conserved residues of these enzymes, as well as the structural changes responsible for triggering the release of the product from the active site, were identified. Asp89*/Asp88* from a neighbouring enzyme subunit proved to be the residue responsible for the deprotonation of the essential tyrosine to afford the catalytic tyrosinate, which triggers the enzymatic process. The essentiality of this residue is supported by results from site-directed mutagenesis. For H. pylori DHQ2, this reaction takes place through the assistance of a water molecule, whereas for M. tuberculosis DHQ2, the tyrosine is directly deprotonated by the aspartate residue. The participation of a water molecule in this deprotonation reaction is supported by solvent isotope effects and proton inventory studies. MD simulation studies provide details of the required motions for the catalytic turnover, which provides a complete overview of the catalytic cycle. The product is expelled from the active site by the essential arginine residue and after a large conformational change of a loop containing two conserved arginine residues (Arg109/Arg108 and Arg113/Arg112), which reveals a previously unknown key role for these residues. The present study highlights the key role of the aspartate residue whose blockage could be useful in the rational design of inhibitors and the mechanistic differences between both enzymes.


Assuntos
Proteínas de Bactérias/química , Helicobacter pylori/enzimologia , Hidroliases/química , Mycobacterium tuberculosis/enzimologia , Arginina/química , Ácido Aspártico/química , Proteínas de Bactérias/genética , Catálise , Hidroliases/genética , Cinética , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Teoria Quântica , Solventes
13.
J Am Chem Soc ; 135(33): 12366-76, 2013 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-23889343

RESUMO

Shikimate kinase (SK) is an essential enzyme in several pathogenic bacteria and does not have any counterpart in human cells, thus making it an attractive target for the development of new antibiotics. The key interactions of the substrate and product binding and the enzyme movements that are essential for catalytic turnover of the Mycobacterium tuberculosis shikimate kinase enzyme (Mt-SK) have been investigated by structural and computational studies. Based on these studies several substrate analogs were designed and assayed. The crystal structure of Mt-SK in complex with ADP and one of the most potent inhibitors has been solved at 2.15 Å. These studies reveal that the fixation of the diaxial conformation of the C4 and C5 hydroxyl groups recognized by the enzyme or the replacement of the C3 hydroxyl group in the natural substrate by an amino group is a promising strategy for inhibition because it causes a dramatic reduction of the flexibility of the LID and shikimic acid binding domains. Molecular dynamics simulation studies showed that the product is expelled from the active site by three arginines (Arg117, Arg136, and Arg58). This finding represents a previously unknown key role of these conserved residues. These studies highlight the key role of the shikimic acid binding domain in the catalysis and provide guidance for future inhibitor designs.


Assuntos
Biocatálise , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Mycobacterium tuberculosis/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Difosfato de Adenosina/metabolismo , Domínio Catalítico , Inibidores Enzimáticos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/química , Ácido Chiquímico/química , Ácido Chiquímico/metabolismo
14.
Cell ; 152(3): 383-4, 2013 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-23374333

RESUMO

Self-interacting BAX proteins permeabilize outer mitochondrial membranes to trigger apoptotic cell death. Czabotar et al. present two revealing structures of BAX dimers: one dimer has an activator BH3 helix bound into its canonical cleft, and the other dimer exposes a planar hydrophobic face potentially critical for membrane interactions.

15.
ACS Chem Biol ; 8(3): 568-77, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23198883

RESUMO

The structural changes caused by the substitution of the aromatic moiety in (2S)-2-benzyl-3-dehydroquinic acids and its epimers in C2 by electron-withdrawing or electron-donating groups in type II dehydroquinase enzyme from M. tuberculosis and H. pylori has been investigated by structural and computational studies. Both compounds are reversible competitive inhibitors of this enzyme, which is essential in these pathogenic bacteria. The crystal structures of M. tuberculosis and H. pylori in complex with (2S)-2-(4-methoxy)benzyl- and (2S)-2-perfluorobenzyl-3-dehydroquinic acids have been solved at 2.0, 2.3, 2.0, and 1.9 Å, respectively. The crystal structure of M. tuberculosis in complex with (2R)-2-(benzothiophen-5-yl)methyl-3-dehydroquinic acid is also reported at 1.55 Å. These crystal structures reveal key differences in the conformation of the flexible loop of the two enzymes, a difference that depends on the presence of electron-withdrawing or electron-donating groups in the aromatic moiety of the inhibitors. This loop closes over the active site after substrate binding, and its flexibility is essential for the function of the enzyme. These differences have also been investigated by molecular dynamics simulations in an effort to understand the significant inhibition potency differences observed between some of these compounds and also to obtain more information about the possible movements of the loop. These computational studies have also allowed us to identify key structural factors of the H. pylori loop that could explain its reduced flexibility in comparison to the M. tuberculosis loop, specifically by the formation of a key salt bridge between the side chains of residues Asp18 and Arg20.


Assuntos
Inibidores Enzimáticos/farmacologia , Hidroliases/antagonistas & inibidores , Ácido Quínico/análogos & derivados , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Helicobacter pylori/enzimologia , Hidroliases/metabolismo , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Mycobacterium tuberculosis/enzimologia , Ácido Quínico/síntese química , Ácido Quínico/química , Ácido Quínico/farmacologia
16.
Org Biomol Chem ; 10(18): 3662-76, 2012 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-22447158

RESUMO

Several 3-alkylaryl mimics of the enol intermediate in the reaction catalyzed by type II dehydroquinase were synthesized to investigate the effect on the inhibition potency of replacing the oxygen atom in the side chain by a carbon atom. The length and the rigidity of the spacer was also studied. The inhibitory properties of the reported compounds against type II dehydroquinase from Mycobacterium tuberculosis and Helicobacter pylori are also reported. The binding modes of these analogs in the active site of both enzymes were studied by molecular docking using GOLD 5.0 and dynamic simulations studies.


Assuntos
Enoil-CoA Hidratase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Cetonas/farmacologia , Mimetismo Molecular , Enoil-CoA Hidratase/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Helicobacter pylori/enzimologia , Cetonas/síntese química , Cetonas/química , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Mycobacterium tuberculosis/enzimologia , Estereoisomerismo , Relação Estrutura-Atividade
17.
FEBS Lett ; 586(6): 675-9, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22449962

RESUMO

MbeA and MbeC are two key proteins in plasmid ColE1 conjugal mobilization. Isothermal titration calorimetry was used to detect and quantify an interaction between MbeA and MbeC. As a result of this interaction, the affinity of MbeA for single stranded DNA increased. The interaction was confirmed in vivo using a bacterial two-hybrid system, which revealed that MbeA-MbeC complexes are formed through the amino-terminal region of MbeA and the carboxy-terminal region of MbeC. To the best of our knowledge, this is the first report of direct interactions between conjugative proteins encoded by a mobilizable plasmid.


Assuntos
Proteínas de Bactérias/metabolismo , Endodesoxirribonucleases/metabolismo , Plasmídeos/metabolismo , Proteínas de Bactérias/genética , Sequência de Bases , Conjugação Genética , DNA de Cadeia Simples/metabolismo , Endodesoxirribonucleases/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Dados de Sequência Molecular , Plasmídeos/genética , Técnicas do Sistema de Duplo-Híbrido
18.
J Med Chem ; 54(17): 6063-84, 2011 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-21780742

RESUMO

The synthesis of high-affinity reversible competitive inhibitors of Mycobacterium tuberculosis type II dehydroquinase, an essential enzyme in Mycobacterium tuberculosis bacteria, is reported. The inhibitors reported here are mimics of the enol intermediate and the effect of substitution on C2 was studied. The crystal structures of Mycobacterium tuberculosis type II dehydroquinase in complex with three of the reported inhibitors are also described. The results show that an aromatic substituent on C2 prevents the closure of the active site by impeding the hydrogen-bonding interaction of Arg108 with the essential Tyr24 of the flexible loop, the residue that initiates catalysis. Chemical modifications of the reported acids were also carried out to improve internalization into Mycobacterium tuberculosis through an ester prodrug approach. Propyl esters proved to be the most efficient in achieving optimal in vitro activities.


Assuntos
Antituberculosos/farmacologia , Inibidores Enzimáticos/farmacologia , Hidroliases/antagonistas & inibidores , Mycobacterium tuberculosis/efeitos dos fármacos , Pró-Fármacos/farmacologia , Antituberculosos/síntese química , Antituberculosos/química , Catálise , Domínio Catalítico , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Mycobacterium tuberculosis/crescimento & desenvolvimento , Oxazinas , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade , Xantenos
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