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1.
BMC Public Health ; 21(1): 599, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33771155

RESUMO

BACKGROUND: Employees who engage in proactive burnout prevention can prevent burnout by changing aspects of the work, home, and personal domain. However, these proactive behaviors may be impeded by high initial levels of burnout. Based on the conservation of resources theory and the dual-pathway proactivity model, resources were expected to play a vital role in the relationship between proactive burnout prevention and burnout through two distinct processes: a resource-generation process in which proactive burnout prevention negatively affects burnout through an increase in resources, and a resource-depletion process in which proactive burnout prevention is hindered because high initial levels of burnout negatively affected resources. METHODS: A two-wave longitudinal panel design was used in which 617 employees, mainly employed in government agencies, healthcare and education, were asked to complete an online survey twice with an interval of 1 month. RESULTS: Results of structural equation modelling showed clear evidence for the resource-generation process in the work, home, and personal domain, and only limited evidence for the resource-depletion process. Solely in the personal domain a small negative indirect effect of burnout on proactive burnout prevention through personal resources was found. CONCLUSIONS: The findings of this study confirm that employees can proactively prevent burnout by investing in resources, yet proactive actions should be taken before increased burnout-complaints impede employees to do so. This study contributes to scientific knowledge on proactive behaviors and burnout prevention by investigating the mechanism underlying the temporal relationship between proactive burnout prevention and burnout. An important practical implication of this study is that it highlights that more attention should be given to employees' self-initiated actions to prevent burnout, as proactive burnout prevention can effectively reduce levels of burnout.


Assuntos
Esgotamento Profissional , Esgotamento Profissional/prevenção & controle , Humanos , Inquéritos e Questionários
2.
J Nurs Manag ; 24(7): 915-922, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27237454

RESUMO

AIM: This study investigated whether Nigerian nurses' emotional exhaustion and active learning were predicted by job demands, control and social support. BACKGROUND: Limited research has been conducted concerning nurses' work stress in developing countries, such as Nigeria. Accordingly, it is not clear whether work interventions for improving nurses' well-being in these countries can be based on work stress models that are developed in Western countries, such as the job demand control support model, as well as on empirical findings of job demand control support research. METHOD: Nurses from Nurses Across the Borders Nigeria were invited to complete an online questionnaire containing validated scales; 210 questionnaires were fully completed and analysed. Multiple regression analysis was used to test the hypotheses. RESULTS: Emotional exhaustion was higher for nurses who experienced high demands and low supervisor support. Active learning occurred when nurses worked under conditions of high control and high supervisor support. CONCLUSION: The findings suggest that the job demand control support model is applicable in a Nigerian nursing situation; the model indicates which occupational stressors contribute to poor well-being in Nigerian nurses and which work characteristics may boost nurses' active learning. IMPLICATIONS FOR NURSING MANAGEMENT: Job (re)design interventions can enhance nurses' well-being and learning by guarding nurses' job demands, and stimulating job control and supervisor support.


Assuntos
Satisfação no Emprego , Aprendizagem , Enfermeiras e Enfermeiros/psicologia , Carga de Trabalho/normas , Adulto , Atitude do Pessoal de Saúde , Feminino , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Nigéria , Análise de Regressão , Apoio Social , Estresse Psicológico/etiologia , Inquéritos e Questionários , Carga de Trabalho/psicologia
3.
Transgenic Res ; 22(4): 709-23, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23111619

RESUMO

Targeted transgenesis using site-specific recombinases is an attractive method to create genetically modified animals as it allows for integration of the transgene in a pre-selected transcriptionally active genomic site. Here we describe the application of recombinase-mediated cassette exchange (RMCE) in cells from a Göttingen minipig with four RMCE acceptor loci, each containing a green fluorescence protein (GFP) marker gene driven by a human UbiC promoter. The four RMCE acceptor loci segregated independent of each other, and expression profiles could be determined in various tissues. Using minicircles in RMCE in fibroblasts with all four acceptor loci and followed by SCNT, we produced piglets with a single copy of a transgene incorporated into one of the transcriptionally active acceptor loci. The transgene, consisting of a cDNA of the Alzheimer's disease-causing gene PSEN1M146I driven by an enhanced human UbiC promoter, had an expression profile in various tissues similar to that of the GFP marker gene. The results show that RMCE can be done in a pre-selected transcriptionally active acceptor locus for targeted transgenesis in pigs.


Assuntos
Técnicas de Transferência Nuclear , Presenilina-1/genética , Porco Miniatura/genética , Transgenes , Animais , Animais Geneticamente Modificados , DNA Complementar/genética , Fibroblastos/citologia , Fibroblastos/metabolismo , Genoma , Humanos , Recombinases/genética , Suínos
4.
J Adv Nurs ; 69(1): 31-40, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22420721

RESUMO

AIM: To provide insight into the individual and contextual factors that are related to intensive care nursing staff perceptions of work pressure and turnover. BACKGROUND: Hospitals are facing a shortage of intensive care nurses that will only become more pressing owing to demographic changes. Nurses' sickness absence and turnover are considered important threats to the supply of intensive care. DESIGN: A quantitative, cross-sectional research design was used that was preceded by a qualitative, explorative study. METHOD: First, interviews and observations took place to better understand intensive care nurses' work situation. Next, quantitative data were obtained in 2010 from 461 Dutch qualified intensive care nurses who completed a questionnaire. FINDINGS: The outcomes of multiple regression analyses indicated that nurses' perceptions of work pressure were predicted by emotional demands, physical demands, threats from patients' relatives, social support and autonomy. Turnover intention was predicted by age, ability to deal with night shifts, social support and development opportunities. CONCLUSIONS: Given the importance of the availability of staff to secure intensive care, this study indicates that hospitals should pay more attention to intensive care nurses' work situation. Decreasing emotional and physical demands and increasing nurses' development opportunities are some of the measures hospitals can take to create a work environment that better accommodates the needs of their intensive care nursing staff.


Assuntos
Unidades de Terapia Intensiva , Recursos Humanos de Enfermagem Hospitalar/psicologia , Reorganização de Recursos Humanos , Estresse Psicológico , Estudos Transversais , Humanos , Países Baixos , Inquéritos e Questionários , Recursos Humanos
5.
Front Psychol ; 13: 1054053, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36591030

RESUMO

Introduction: Burnout complaints are high for Dutch police officers. According to Hobfoll's Conservation of Resources theory, resources such as coping self-efficacy can play an important role in the burnout process. The aim of this study was to investigate the buffering effect of coping self-efficacy on burnout, as well as a possible depletion effect of burnout on coping self-efficacy. Methods: As such, this research consists of two studies namely, a two-wave study (N = 166) and three-wave study (N = 95) on Dutch police officers. They expand on previous research regarding coping resources and police burnout. Results: Both studies show that the chronic stressor, work scheduling, was positively associated with burnout. Also, coping self-efficacy weakened the effect of work scheduling (Study 1) and workload (Study 2) on burnout. Moreover, there was a direct negative relationship between burnout and coping self-efficacy. Discussion: The results indicate that burnout can lead to lower coping resources, initiating a potential cycle of resource loss and burnout. Further investigation into this depletion effect is required to provide police officers and organisations with tools to prevent burnout.

6.
Health Care Manage Rev ; 36(2): 155-63, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21317664

RESUMO

BACKGROUND: The retention of nurse anesthetists is of paramount importance, particularly in view of the fact that the health care workforce is shrinking. Although many health care providers find their work satisfying, they often consider leaving their jobs because of the stress. Are there ways to improve this situation? PURPOSE: This study investigated how work environment characteristics and personality dimensions relate to burnout and job satisfaction and ultimately to turnover intention among Dutch nurse anesthetists. METHODOLOGY: An online self-reporting questionnaire survey was performed among Dutch nurse anesthetists. The questionnaire included scales to assess personality dimensions, work climate, work context factors, burnout, job satisfaction, and turnover intention. The research model stated that personality dimensions, work climate, and work context factors, mediated by burnout and job satisfaction, predict turnover intention. Structural equation modeling was used to test the research model. FINDINGS: Nine hundred twenty-three questionnaires were completed (46% response rate). Burnout mediated the relationship between personality dimensions and turnover intention; job satisfaction mediated the relationship of work climate and work context factors to turnover intention. PRACTICE IMPLICATIONS: To retain nursing staff and to maintain adequate staff strength, it is important to improve job satisfaction by creating a positive work climate and work context and to prevent burnout by selecting the most suitable employees through personality assessment.


Assuntos
Esgotamento Profissional , Satisfação no Emprego , Enfermeiros Anestesistas/psicologia , Personalidade , Lealdade ao Trabalho , Adulto , Humanos , Pessoa de Meia-Idade , Países Baixos , Inquéritos e Questionários
7.
AANA J ; 79(1): 63-70, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21473228

RESUMO

Finding ways to retain nurse anesthetists in the profession to meet the increasing demands of the healthcare system is of paramount importance. The present study investigates the relationship between work climate and job satisfaction among Dutch nurse anesthetists. A questionnaire was distributed to Dutch nurse anesthetists to assess their perceptions of their work climates, and their levels of job satisfaction. Multiple regression analyses were performed to obtain the predictive value of work climate for job satisfaction. All of the work climate characteristics had statistically significant correlations to job satisfaction, and explained 20% of the variance in job satisfaction. To achieve a higher level of job satisfaction among nurse anesthetists, it is necessary to improve some essential work climate characteristics, such as: (1) making the nurse anesthetist feel an important part of the organization's mission statement, (2) discussing progress at work, (3) giving recognition for delivered work, (4) encouraging development, and (5) providing sufficient opportunities to learn and to grow.


Assuntos
Satisfação no Emprego , Enfermeiros Anestesistas/organização & administração , Enfermeiros Anestesistas/estatística & dados numéricos , Cultura Organizacional , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Inquéritos e Questionários , Adulto Jovem
8.
Anestezjol Intens Ter ; 43(3): 157-62, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22011919

RESUMO

BACKGROUND: In the Netherlands, the employment as a "nurse anaesthetist" is comparable to that of a registered nurse anaesthetist in the Scandinavian countries and Poland. However, the Dutch healthcare system employs nurse anaesthetists both with and without nursing backgrounds. This study has investigated whether a nursing background influences the attitudes and perceptions of nurse anaesthetists in the Netherlands. METHODS: A survey was distributed to all nurse anaesthetists working in Dutch hospitals to discover differences in their perceptions of their work context, job satisfaction, and work climate, as well as health and turnover intention. The questionnaire also sought basic information on socio-demographic factors and psychosomatic symptoms. Descriptive statistics, factor analyses and independent T-tests were computed. RESULTS: Overall 923 of a total of 2,000 questionnaires were completed and analysed (response rate of 46%). Independent T-tests showed no significant differences between nurse anaesthetists with and those without nursing backgrounds in all the areas examined. CONCLUSION: Dutch nurse anaesthetists with and without nursing backgrounds reported similar perceptions of and information about their work context, job satisfaction, work climate, psychosomatic symptoms, burnout, sickness absence, general health and turnover intention. Both academic tracks appeared to produce individuals who functioned similarly as professionals.


Assuntos
Competência Clínica , Enfermeiros Anestesistas/estatística & dados numéricos , Papel do Profissional de Enfermagem , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Adulto , Esgotamento Profissional/epidemiologia , Escolaridade , Feminino , Humanos , Satisfação no Emprego , Masculino , Países Baixos , Enfermeiros Anestesistas/economia , Enfermeiros Anestesistas/psicologia , Pesquisa Metodológica em Enfermagem , Recursos Humanos de Enfermagem Hospitalar/psicologia , Inquéritos e Questionários , Local de Trabalho , Adulto Jovem
9.
BMJ Case Rep ; 14(4)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33910789

RESUMO

A 62-year-old woman presented with unilateral inguinal lymphadenopathy, existing for several months. As it was initially thought to be lymphoma, the lymph node was resected. Pathology, however, revealed a metastasis of a high-grade papillary serous cancer, according to its stainings, most likely ovarian in origin. Further staging showed lymphadenopathies in the inguinofemoral, para-aortic and mediastinal regions. Consequently, the multidisciplinary oncologic meeting advised a diagnostic laparoscopy which showed no macroscopic spread within the abdomen. Pathological examination of biopsies as well as both ovaries showed no sign of ovarian cancer. The patient received standard chemotherapy, that is, carbo-Taxol-Avastin, to which she showed complete response after three cycles as shown on positron emission tomography-CT. A review of existing literature showed that this is a very unusual case of high-grade serous carcinoma, where no site of origin could be found.


Assuntos
Linfadenopatia , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Neoplasias Ovarianas/diagnóstico , Tomografia Computadorizada por Raios X
10.
Stress Health ; 37(4): 766-777, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33608986

RESUMO

Given the detrimental effects of burnout for individuals and organizations, it is of crucial importance to better understand the self-initiated actions employees take to prevent burnout. While such proactive burnout prevention is likely to reduce burnout complaints, these activities may also be frustrated by high burnout levels. This means that proactive burnout prevention and burnout can negatively affect each other over time. The present study used a four-wave longitudinal panel design to investigate temporal relationships between proactive burnout prevention and burnout over 3, 6 and 9 weeks. Participants were 165 employees in the financial services industry who provided data on all four measurement occasions. The outcomes of structural equation modelling provided support for the hypothesized combined effects model compared to the lagged and reversed effects models. The findings suggest that proactive burnout prevention can help to prevent burnout, while engagement in these behaviours may be hindered by high initial levels of burnout. Employees should therefore intervene before their resource pool becomes too depleted and they lack the energy or mental strength to invest resources, in order to proactively retain or regain resources.


Assuntos
Esgotamento Profissional , Esgotamento Profissional/prevenção & controle , Humanos , Estudos Longitudinais , Inquéritos e Questionários
11.
North Clin Istanb ; 8(1): 101-105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33623880

RESUMO

Mycosis fungoides (MF) is an indolent form of non-Hodgkin lymphoma and the most common type of primary cutaneous T-cell lymphoma. The overall incidence of MF is approximately 4 per 1 million. Involvement of the vulva by MF is extremely rare, with only seven reported cases in the literature. At the vulva, it is mainly a metastatic lesion and rarely a primary malignancy. We describe a case of vulvar MF and discuss the previous cases. The presentation can easily be confused with benign skin disorders. A vulvar lesion can reflect a systemic disease. When a patient consults for a vulvar lesion it is therefore important not only to look at the vulva but also to examine her in and ask general questions. In a patient with a vulvar mass and cutaneous lesions on other locations MF should be considered in the differential diagnosis.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33050017

RESUMO

Owing to work intensification and an accelerated pace of life in general, individuals in many Western countries are often overactivated and find it difficult to switch off. However, recovery from physiological and mental activation is critical to prevent stress symptoms and maintain one's physiological and mental well-being. Extensive research evidence indicates that Qigong, a traditional Chinese movement practice for promoting health, provides an effective means to recover from work and off-work demands. The main objective of this paper is to offer a comprehensive, narrative review of the effects of Qigong and its core components. Attention is first paid to the outcomes of work and off-work demands and stress, and the role of recovery for individuals' well-being. Then, Qigong and its components are explained, followed by the results of scientific research. Finally, limitations and implications for research and practiced are discussed.


Assuntos
Qigong , Humanos , Saúde Mental
13.
Artigo em Inglês | MEDLINE | ID: mdl-32151047

RESUMO

Proactive burnout prevention refers to a set of proactive behaviors employees may engage in to prevent burnout. Findings of a previous exploratory qualitative study indicated that employees who had to deal with high demands engaged in specific proactive behaviors in the work, home, and personal domain in order to prevent burnout. To further examine proactive burnout prevention in longitudinal quantitative research and to be able to investigate its effectiveness, an inventory for assessing these kinds of behaviors is necessary. The goal of this study was twofold: 1) to develop an inventory to assess employees' proactive burnout prevention behaviors and examine its factorial validity, 2) to explore the broader nomological network of proactive burnout prevention behaviors by examining its convergent, discriminant, and predictive validity. A two-wave longitudinal survey (T1: N = 343; T2: N = 201) was conducted. The results of exploratory and confirmatory factor analysis showed that proactive burnout prevention can be reliably assessed with 40 items that load on 12 factors, indicating 12 separate proactive burnout prevention behaviors. Moreover, exploration of the convergent, discriminant, and predictive validity of the proactive burnout prevention inventory showed promising results, as expected relationships were confirmed for most behaviors. Further research is needed to substantiate the findings and examine the effectiveness of proactive burnout prevention.


Assuntos
Esgotamento Profissional , Saúde Ocupacional , Esgotamento Profissional/prevenção & controle , Esgotamento Profissional/psicologia , Análise Fatorial , Humanos , Inquéritos e Questionários
14.
Front Psychol ; 11: 1308, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32625151

RESUMO

Based on lifespan developmental psychology and psychosocial work characteristics theory, we examined longitudinal relations between calendar age, occupational time perspective, different types of job demands and job resources in relation to sustainable employability (i.e., work ability, vitality and employability) among healthcare workers in Netherlands (N = 1478). Results of our two-wave complete panel study revealed satisfactory fit indices for the metric invariance of the included variables across the two waves (6-month time lag). Our results revealed a negative relation between calendar age and external employability of healthcare workers (limited support for hypothesis 1), and more consistent evidence for positive relations between an open future time perspective and across-time changes in vitality, work ability and external employability (supporting hypothesis 2). Few significant findings were found for relations between specific job demands or job resources and indicators of sustainable employability of healthcare workers (mixed results hypotheses 3 and 4). Our explorative tests of possible moderating effects of age or occupational time perspective in predicting relations between psychosocial work characteristics and indicators of sustainable employability revealed only a significant interaction effect of supervisor support and future time perspective in explaining across-time changes in external employability of healthcare workers (rejecting hypothesis 5 and confirming hypothesis 6). We discuss the practical as well as theoretical implications of these findings, and present recommendations for future research.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31614684

RESUMO

Extensive evidence indicates that burnout can have detrimental consequences for individuals as well as organizations; therefore, there is a great need for burnout prevention. While burnout prevention interventions initiated by the employer have previously been studied, the proactive behaviors employees deploy themselves to prevent burnout have received less research attention. The purpose of this exploratory qualitative interview study was to enhance our understanding of the self-initiated actions employees undertake to prevent burnout, using the model of proactive motivation and conservation of resources theory as theoretical frameworks. Findings indicated that most participants reported to engage in specific kinds of proactive burnout prevention behaviors. The reported self-initiated proactive actions were aimed at maintaining and/or increasing resources and/or reducing demands in the work, home, and personal domain. The study contributes to the literature by linking the proactive motivation process to the prevention of burnout and by focusing on both work and non-work factors. Results of this study can be used in further research into the (effectiveness of) employees' proactive burnout prevention behaviors and serve as a starting point for developing interventions aimed at enhancing proactive burnout prevention.


Assuntos
Esgotamento Profissional/prevenção & controle , Comportamentos Relacionados com a Saúde , Trabalho/psicologia , Esgotamento Profissional/psicologia , Humanos , Inquéritos e Questionários
16.
Artigo em Inglês | MEDLINE | ID: mdl-31126157

RESUMO

Prior research indicates that workplace changes can have both positive and negative consequences for employees. To explore the mechanisms that trigger these different outcomes, we propose and test a mediation model, which builds on the premises of the challenge-hindrance model of work stress. Specifically, we suggest that whereas workplace changes can engender positive outcomes (e.g., learning outcomes) through an increase in learning demands, they can also enhance negative outcomes (e.g., emotional exhaustion) through increased perceptions of qualitative job insecurity. While we made these specific assumptions, we also analyzed the reversed causation relationships. Two-wave data obtained from 1366 Dutch employees were used to test the study hypotheses. The results showed that the reciprocal causation model had the best fit for the data. However, whereas emotional exhaustion was only mediated by qualitative job insecurity, no mediation was found by learning demands. In addition to the hypothesized effects, several reversed causation effects emerged from the analyses, indicating that the relationships between workplace changes and employee learning and strain are not unidirectional. This underscores the need for a broader view on the causes and effects of workplace changes, as the traditional causation relationships (i.e., perceptions of workplace changes impacting employee learning and strain experiences) are insufficient to explain the complex dynamics between the studied phenomena.


Assuntos
Estresse Ocupacional , Inovação Organizacional , Local de Trabalho/psicologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
17.
J Appl Psychol ; 93(4): 935-44, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18642996

RESUMO

The concept of dispositional resistance to change has been introduced in a series of exploratory and confirmatory analyses through which the validity of the Resistance to Change (RTC) Scale has been established (S. Oreg, 2003). However, the vast majority of participants with whom the scale was validated were from the United States. The purpose of the present work was to examine the meaningfulness of the construct and the validity of the scale across nations. Measurement equivalence analyses of data from 17 countries, representing 13 languages and 4 continents, confirmed the cross-national validity of the scale. Equivalent patterns of relationships between personal values and RTC across samples extend the nomological net of the construct and provide further evidence that dispositional resistance to change holds equivalent meanings across nations.


Assuntos
Afeto , Atitude , Inovação Organizacional , Valores Sociais , Adulto , Comparação Transcultural , Feminino , Humanos , Masculino , Inquéritos e Questionários
18.
J Soc Psychol ; 157(1): 16-29, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-26886252

RESUMO

Victims of workplace mobbing show diverse coping behavior. We investigated the impact of this behavior on bystander cognitions, emotions, and helping toward the victim, integrating coping literature with attribution theory. Adult part-time university students (N = 161) working at various organizations participated in a study with a 3(Coping: approach/avoidance/neutral) × 2(Gender Victim: male/female) × 2(Gender Bystander: male/female) design. Victims showing approach (vs. avoidance) coping were considered to be more self-reliant and less responsible for the continuation of the mobbing, and they elicited less anger. Continuation responsibility and self-reliance mediated the relationship between the victim's coping behavior and bystanders' helping intentions. Female (vs. male) participants reported more sympathy for the victim and greater willingness to help, and female (vs. male) victims elicited less anger. Theoretical and practical implications of the findings are discussed.


Assuntos
Adaptação Psicológica , Bullying , Vítimas de Crime/psicologia , Comportamento Social , Local de Trabalho/psicologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
19.
J Appl Psychol ; 91(3): 555-66, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16737354

RESUMO

This study examined gender differences in a large-scale assessment center for officer entry in the British Army. Subgroup differences were investigated for a sample of 1,857 candidates: 1,594 men and 263 women. A construct-driven approach was chosen (a) by examining gender differences at the construct level, (b) by formulating a priori hypotheses about which constructs would be susceptible to gender effects, and (c) by using both effect size statistics and latent mean analyses to investigate gender differences in assessment center ratings. Results showed that female candidates were rated notably higher on constructs reflecting an interpersonally oriented leadership style (i.e., oral communication and interaction) and on drive and determination. These results are discussed in light of role congruity theory and of the advantages of using latent mean analyses.


Assuntos
Liderança , Papel Profissional , Adolescente , Adulto , Feminino , Humanos , Masculino , Fatores Sexuais
20.
PLoS One ; 10(3): e0119207, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25793507

RESUMO

Nucleic acid aptamer selection is a powerful strategy for the development of regulatory agents for molecular intervention. Accordingly, aptamers have proven their diligence in the intervention with serine protease activities, which play important roles in physiology and pathophysiology. Nonetheless, there are only a few studies on the molecular basis underlying aptamer-protease interactions and the associated mechanisms of inhibition. In the present study, we use site-directed mutagenesis to delineate the binding sites of two 2´-fluoropyrimidine RNA aptamers (upanap-12 and upanap-126) with therapeutic potential, both binding to the serine protease urokinase-type plasminogen activator (uPA). We determine the subsequent impact of aptamer binding on the well-established molecular interactions (plasmin, PAI-1, uPAR, and LRP-1A) controlling uPA activities. One of the aptamers (upanap-126) binds to the area around the C-terminal α-helix in pro-uPA, while the other aptamer (upanap-12) binds to both the ß-hairpin of the growth factor domain and the kringle domain of uPA. Based on the mapping studies, combined with data from small-angle X-ray scattering analysis, we construct a model for the upanap-12:pro-uPA complex. The results suggest and highlight that the size and shape of an aptamer as well as the domain organization of a multi-domain protein such as uPA, may provide the basis for extensive sterical interference with protein ligand interactions considered distant from the aptamer binding site.


Assuntos
Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Sítios de Ligação , Domínio Catalítico , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Técnica de Seleção de Aptâmeros , Espalhamento a Baixo Ângulo , Ativador de Plasminogênio Tipo Uroquinase/química , Difração de Raios X
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