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1.
Front Aging Neurosci ; 15: 1216052, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37539345

RESUMO

The purpose of this study was to compare the effects of music therapy (MT) and/or physical rehabilitation (PR) on cognitive and motor function in elderly Tunisian male and female patients with mild Alzheimer's disease (AD). Male patients (N: 16; age: 74.19 ± 4.27 years; weight: 76.71 ± 5.22 kg) and female patients (N: 12; age: 71.46 ± 3.36 years; weight: 67.47 ± 4.31 kg) with mild AD were randomly assigned into 4 groups including control group (Co), PR group participated in physical rehabilitation, MT group received music therapy and MT + PR received both music therapy and physical rehabilitation. Participants were required to engage in the study for four months with three 60-min sessions per week. We found all scores of cognitive (MMSE, ADAS-Cog Total and the ADAS-Cog Memory subscale) and motor functions (step length, walking speed, 6MVT and BBS score) evaluated were the greatest in MT + PR compared to the other groups. Our study also demonstrated that MT has a greater effect on cognitive function, while PR has a more pronounced effect on motor function. Changes in MMSE scores were significantly positively correlated in the PR, MT and MT + PR groups with improvements in all motor functions including step length (r = 0.77), walking speed (r = 0.73), 6MVT (r = 0.75) and BBS scores (r = 0.78) in AD patients. In conclusion, the combination of MT and PR seems to be an appropriate intervention approach that needs consideration as a treatment strategy for elderly male and female patients with mild AD.

2.
Front Physiol ; 13: 839099, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35991172

RESUMO

Changes in salivary testosterone (T) and cortisol (C) levels were assessed in elderly Tunisian male patients with mild Alzheimer's disease (AD) subjected to music therapy and/or physical rehabilitation. Male patients with mild AD (N = 26; age = 76.23 ± 4.27 years; weight: 74.76 ± 5.36 kg) were randomly assigned into four groups for three 60-min sessions per week for 4 months; including Group1 or control group (Co) (n = 6); Group2 (n = 6), participated in physical rehabilitation (PR); Group3 (n = 7), subjected to music therapy (MT) and Group4 (n = 7), participated simultaneously in music therapy and physical rehabilitation (MT + PR). Salivary T levels increased (ηp2 = 0.7) and C levels decreased (ηp2 = 0.69), significantly (p < 0.001) in the PR, MT and MT + PR groups compared to the Co group respectively. Also, increases in salivary T levels and decreases in C levels in MT + PR group were greater compared to the other groups. MT increased T levels (p < 0.001) and decreased C levels (p < 0.05) to a greater extent than the PR group respectively. Changes in salivary T levels were positively (r = 0.83; p < 0.001) and C levels were negatively (r = -0.86; p < 0.001) correlated in the PR, MT and MT + PR groups with changes in MMSE in AD patients. This study highlights that combination of MT and PR holds potential to treat AD.

3.
Life (Basel) ; 11(2)2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562480

RESUMO

BACKGROUND: The objectives of this systematic review and meta-analysis were to quantify the effectiveness of endurance training (ET) on aerobic performance (i.e., peak oxygen uptake (VO2peak)) in healthy and unhealthy middle and very old adults aged 70 years and older, and to provide dose-response relationships of training prescription variables (in terms of frequency, and volume). METHODS: Several scholarly databases (i.e., PubMed/MEDLINE, SpringerLink, ScienceDirect Journals, and Taylor & Francis Online-Journals) were searched, identifying randomized controlled studies that investigated the effectiveness of ET on VO2peak in older adults. Standardized mean differences (SMD) were calculated. RESULTS: In terms of changes differences between experimental and control group, ET produced significant large effects on VO2peak performance (SMD = 2.64 (95%CI 0.97-4.31)). The moderator analysis revealed that "health status" variable moderated ET effect onVO2peak performance. More specifically, ET produced larger SMD magnitudes on VO2peak performance in healthy compared with unhealthy individuals. With regard to the dose-response relationships, findings from the meta-regression showed that none of the included training prescription variables predicted ET effects on VO2peak performance. CONCLUSIONS: ET is an effective mean for improving aerobic performance in healthy older adults when compared with their unhealthy counterparts.

4.
Biol Sport ; 35(2): 121-136, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30455540

RESUMO

Striking combat sports are challenging, commonly stressing the endocrinological system based on a mixture of body-contact actions and physiological efforts. The aims of this systematic review and meta-analysis were to discuss the hormonal responses related to striking combat sports competitions and to investigate the moderator and mediator variables of the hormonal response-competition/outcome relationship. Three electronic databases (i.e., PubMed, Google Scholar and ScienceDirect) were systematically searched (up to February 2016) followed by a manual search of retrieved papers. The data showed a moderate increase in cortisol (C) (ES = 0.79; 95% CI 0.31-1.28; p = 0.001), an extremely large increase in adrenaline (ES = 4.22; 95% CI 2.62-5.82; p < 0.001), and a very large increase in noradrenaline (ES = 3.40; 95% CI 1.03-5.76; p = 0.005) and human growth hormone (HGH) levels (ES = 3.69; 95% CI 1.96-5.42; p < 0.001) immediately following the combat events, compared to the control condition i.e., "pre-combat". Furthermore, amateur athletes had a larger increase in C levels compared to highly trained athletes (ES = 2.91 [very large] vs ES = 0.56 [small]), while evening events showed greater alterations in C levels compared to morning events (ES = 1.91 [large] vs ES = 0.48 [small]), without significant differences between them (p = 0.26 and p = 0.06, respectively). The present meta-analysis also showed a small, insignificant increase in testosterone (T) (ES = 0.47 [small]; 95% CI -0.45-0.99; p = 0.074) and a decrease in insulin-like growth factor 1 levels (ES = -0.20 [trivial]; 95% CI -0.78-0.37; p = 0.486) immediately following the combat events, compared to the control condition. The type of combat sports practised, participants' gender, and the nature of competition contests (i.e., official vs simulation) did not moderate the relationship between competition and hormonal response. Additionaly, sub-analysis results showed a significant difference between younger and older athletes (Q = 4.05, p = 0.044), suggesting that after combat, younger individuals (less than 17 years of age) had a small decrease in T levels (ES = -0.58), compared with the moderate increase observed in older individuals (ES = 0.76). In conclusion, irrespective of striking combat sports types, the results showed that both official and simulated bouts are a real stressor of the hormonal system of practitioners. Coaches and applied practitioners should adopt "pre-competitive cognitive/coping strategies" to improve the psychological state that mediates the hormonal changes-competition/outcome relationship of their athletes in order to mitigate athletes' stress.

5.
J Sports Med Phys Fitness ; 58(5): 707-713, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28480685

RESUMO

INTRODUCTION: Rugby is an intermittent team sport, commonly stressing the endocrine system by physiological efforts. However, no review has synthesized the available literature on the hormonal responses to a rugby match. The purpose of this review was to examine the hormonal responses to a rugby match. Mediator and moderator variables for the rugby match-hormonal responses relationship were also discussed. EVIDENCE ACQUISITION: The systematic search was conducted using different databases and according to the Population/Intervention or Exposure/Comparison/Outcome(s) (PICO) criteria. EVIDENCE SYNTHESIS: The data obtained in the present review show that match contests were the moderator variable between rugby match-testosterone changes relationship. Particularly, official matches decreased pre-to-post testosterone levels by 43.9%, while simulated matches increased pre-to-post testosterone levels by 33.6%. There were no significant differences between official and simulated contests for the cortisol response to a rugby match which could be explained in part by the small numbers of included studies and participants (71 high-level male players). Thus, it has been shown that a rugby match provides considerable stress to the endocrine system, which lasts up 38-48 h into the recovery period. CONCLUSIONS: The hormonal assessment of rugby players is a valid tool for monitoring stress during a rugby match and provides the opportunity to identify how athletes cope with stress induced by a competition. The information also provides potential for various mental/recovery strategies that may contribute to performance enhancement.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Futebol Americano/fisiologia , Hidrocortisona/metabolismo , Testosterona/metabolismo , Humanos
6.
PLoS One ; 12(10): e0186100, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29023546

RESUMO

The present systematic review and meta-analysis aimed to assess the perturbations in hormonal and psychological homeostasis in response to soccer match-play. These perturbations were explored according to match outcome (i.e., win versus loss), gender, type of contest (i.e., competitive versus non-competitive fixtures) and competitive level (i.e., novice versus high-level). The review was conducted according to the Population/Intervention or Exposure/Comparison/Outcome(s) (PICO) criteria and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Match outcome, type of contest and competitive levels were moderator variables in the examined steroid hormones responses to a soccer match-play. Different testosterone responses were seen between match winners (increase) and losers (decrease) when compared to pre-game or baseline values (p <0.05), whilst no changes could be detected for cortisol relative to match outcome in female soccer players. Males (Δ% = 6.26; ES = 0.28) demonstrated a marginally lower increase in testosterone levels when compared to females (Δ% = 49.16; ES = 1.00), though not statistically significant. Females (Δ% = 162.7; ES = 0.98) did not demonstrate elevated cortisol match response compared to males (Δ% = 34.60; ES = 1.20). Male novice soccer match-play increased cortisol levels compared to high-level soccer match-play (Q = 18.08, p<0.001). Competitive soccer matches increased cortisol levels compared to non-competitive fixtures (i.e., collegiate tournament). Additionally, competitive levels moderate the relationship between a soccer match and testosterone levels (p <0.001), regardless of gender differences. From the presented systematic review and meta-analysis it appears (1) cortisol changes are associated with cognitive anxiety in starter female soccer players, while (2) testosterone changes are associated with changes in mood state in females and social connectedness in male soccer players. This apparent psycho-physiological relationship may proffer the opportunity for targeted intervention(s) by practitioners to favorably influence performance and/or recovery agendas. Further mechanistic and/or applied evidence is required in this regard in addition to further data sets from females.


Assuntos
Comportamento Competitivo/fisiologia , Hidrocortisona/metabolismo , Futebol/psicologia , Testosterona/metabolismo , Feminino , Humanos , Masculino , Caracteres Sexuais
7.
J Strength Cond Res ; 31(4): 1132-1141, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28081033

RESUMO

Slimani, M, Chaabène, H, Davis, P, Franchini, E, Cheour, F, and Chamari, K. Performance aspects and physiological responses in male amateur boxing competitions: a brief review. J Strength Cond Res 31(4): 1132-1141, 2017-Boxing is one of the most popular striking combat sports in the world. The aim of this review was to present data concerning performance analysis (time-motion and technical-tactical analysis) and physiological responses (i.e., blood lactate concentration [BLC], heart rate, and oxygen consumption) during novice and elite male simulated and official amateur boxing competitions in any age category. The present review shows that boxing competition is a high-intensity intermittent striking combat sport. Typically, the activity-to-rest ratio was higher in elite (18:1) than in novice (9:1) boxers and significant differences were observed between rounds (first round = 16:1, second round = 8:1, and third round = 6:1) in novice boxers. Thus, total stop-time and total stop-frequency increased over subsequent rounds in novice boxers. The technical-tactical aspects in elite and novice boxing bouts were different between rounds and dependent on the match outcome (i.e., winners vs. losers). Particularly, the current review highlights that triple-punch combinations, total combinations, block- and counter-punch combinations, total punches to the head, technical performance effectiveness, and defensive- and offensive-skills effectiveness may have contributed to win in novice and elite boxing competitions. Higher frequencies of technical movements were also observed in elite compared with novice boxers. From a physiological point of view, BLC increased significantly from postround 1 compared with postround 3 in novice boxing match. BLC was also higher in official than in simulated elite boxing matches in senior compared with junior boxers and in medium heavy-weight category compared with light- and medium-weight categories in junior boxing competition. A higher percentage of maximal heart rate (%HRmax) and maximal oxygen uptake (V[Combining Dot Above]O2max) were reported in round 3 compared with rounds 2 and 1 in elite boxing competition. In conclusion, these data are useful for both technical-tactical and physical conditioning sessions. Coaches and fitness trainers are encouraged to adjust their training according to these particular characteristics, specifically in terms of age, participants' level, weight categories, and combat contest type.


Assuntos
Desempenho Atlético/fisiologia , Boxe/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Movimento/fisiologia , Consumo de Oxigênio/fisiologia
8.
J Sports Med Phys Fitness ; 57(7-8): 1069-1079, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27377252

RESUMO

BACKGROUND: The aim of the present study was to examine the effects of mental training on muscular force generation, hormonal alterations, and physiological adaptations in male trained kickboxers. METHODS: Fifty-three male trained kickboxers (24.2±4.4 years, 1.75±0.08 m and 70.4±10.2 kg) were randomly assigned to a physical-training group (PG; N.=20), physical and mental training group (PMG: N.=18, mental-training package [MTP] plus physical training] or control group (CG: N.=15). Physical fitness tests: countermovement jump (CMJ), medicine ball throw (MBT), bench press, and half-squat tests; hormones: resting cortisol (C) blood sample, plasma testosterone (T) concentration, and T/C ratio; and physiological variables: resting heart rate (HR), and blood pressure (BP) were assessed before training commenced (baseline) and at week 6 and 12 of training. RESULTS: PMG and PG improved performance in CMJ height (16.2%, 8.4%), MBT (27.9%, 14.2%), bench press (26.5%, 15.7%), half-squat (27.2%, 16.3%), T concentration (35.2%, 22.4%), and T/C ratio (60%, 0%, for PMG only), respectively. In contrast, the C concentration decreased for the PMG (16.3%) and increased for the PG (22%) after 12 weeks. The PMG and PG had significant decrease from pre- to post-training for the resting HR (9.1%, 3%, respectively) and BP (8.5%, 5.3%, respectively). Furthermore, there was a significant increase in MBT (9.3%) after 6 weeks in PMG. Outlined improvements (PMG and PG) were favorable compared to CG (P<0.05) in all instances. CONCLUSIONS: The greater muscular force generation in PMG than PG seem to be explained by the reduction of hormonal and physiological stress after 12 weeks.


Assuntos
Desempenho Atlético , Boxe/psicologia , Exercício Físico , Força Muscular/fisiologia , Aptidão Física , Adulto , Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Boxe/fisiologia , Estudos de Casos e Controles , Exercício Físico/fisiologia , Exercício Físico/psicologia , Humanos , Hidrocortisona/sangue , Masculino , Aptidão Física/fisiologia , Aptidão Física/psicologia , Distribuição Aleatória , Testosterona/sangue , Adulto Jovem
9.
J Sports Sci ; 34(24): 2338-2349, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27842463

RESUMO

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the "cognitive training-soccer performance" relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7-39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.


Assuntos
Desempenho Atlético/psicologia , Cognição , Motivação , Destreza Motora , Educação Física e Treinamento/métodos , Futebol/psicologia , Humanos , Imaginação
10.
Asian J Sports Med ; 7(2): e30840, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27625755

RESUMO

BACKGROUND: Kickboxing is a high-intensity intermittent striking combat sport, which is characterized by complex skills and tactical key actions with short duration. OBJECTIVES: The present study compared and verified the relationship between mental toughness (MT), countermovement jump (CMJ) and medicine ball throw (MBT) power tests by outcomes of high-level kickboxers during National Championship. MATERIALS AND METHODS: Thirty two high-level male kickboxers (winner = 16 and loser = 16: 21.2 ± 3.1 years, 1.73 ± 0.07 m, and 70.2 ± 9.4 kg) were analyzed using the CMJ, MBT tests and sports mental toughness questionnaire (SMTQ; based in confidence, constancy and control subscales), before the fights of the 2015 national championship (16 bouts). In statistical analysis, Mann-Withney test and a multiple linear regression were used to compare groups and to observe relationships, respectively, P ≤ 0.05. RESULTS: The present results showed significant differences between losers vs. winners, respectively, of total MT (7(7;8) vs. 11(10.2;11), confidence (3(3;3) vs. 4(4;4)), constancy (2(2;2) vs. 3(3;3)), control (2(2;3) vs. 4(4;4)) subscales and MBT (4.1(4;4.3) vs. 4.6(4.4;4.8)). The multiple linear regression showed a strong associations between MT results and outcome (r = 0.89), MBT (r = 0.84) and CMJ (r = 0.73). CONCLUSIONS: The findings suggest that MT will be more predictive of performance in those sports and in the outcome of competition.

11.
Biol Res ; 49: 22, 2016 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-27067415

RESUMO

BACKGROUND: Disturbance of the equilibrium between reactive oxygen species (ROS) and anti-oxidants (AOX) has been implicated in various diseases, including atherosclerosis, the most common pathologic process underlying coronary heart disease (CHD). Thus, the defense systems against ROS are critical protecting blood vessel walls against oxidative damage. In this study, we investigate whether Ala16Val MnSOD and Pro198Leu GPx polymorphisms are associated with CHD susceptibility and/or severity. METHODS: Both polymorphisms were genotyped in a sample of 203 controls and 164 patients. CHD risk and severity, antioxidant status (enzymatic and/or non enzymatic) and biochemical parameters were assessed and analysed by genotype. RESULTS: A significant association of MnSOD variant to CHD risk was revealed in males. Males harboring the Val/Val genotype were approximately at twofold increased risk of CHD compared to controls (Ala carriers vs Val/Val, adjusted OR 1.89; 95 % CI 1.18‒3.42, p = 0.03). Significant decreases in SOD activity and total antioxidant status (TAS) were observed in Val carriers and by CHD status. Whereas, no association of GPx variant genotype (Leu/Leu) and activity to cardiopathy events was discerned. CHD severity, as demonstrated by the number of vessel stenosis, was associated with significantly higher frequency of Val allele and LDL levels in CHD subjects. CONCLUSIONS: Our results showed a lack of association of Pro198Leu GPx polymorphism to CHD risk and severity. However, they suggest that Ala16Val MnSOD polymorphism and decreased antioxidant defences are likely contributed to CHD risk in Tunisian men. Furthermore, the Val encoding MnSOD allele and decreased SOD activity were significantly correlated with CHD stenosis progression.


Assuntos
Doença das Coronárias/genética , Glutationa Peroxidase/genética , Polimorfismo Genético , Superóxido Dismutase/genética , Adulto , Idoso , Análise de Variância , Estudos de Casos e Controles , Doença das Coronárias/patologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Reação em Cadeia da Polimerase , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Tunísia , Glutationa Peroxidase GPX1
12.
J Hum Kinet ; 53: 231-247, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28149427

RESUMO

Plyometric training (PT) is a very popular form of physical conditioning of healthy individuals that has been extensively studied over the last decades. In this article, we critically review the available literature related to PT and its effects on physical fitness in team sport athletes. We also considered studies that combined PT with other popular training modalities (e.g. strength/sprint training). Generally, short-term PT (i.e. 2-3 sessions a week for 4-16 weeks) improves jump height, sprint and agility performances in team sport players. Literature shows that short PT (<8 weeks) has the potential to enhance a wide range of athletic performance (i.e. jumping, sprinting and agility) in children and young adult amateur players. Nevertheless, 6 to 7 weeks training appears to be too short to improve physical performance in elite male players. Available evidence suggests that short-term PT on non-rigid surfaces (i.e. aquatic, grass or sand-based PT) could elicit similar increases in jumping, sprinting and agility performances as traditional PT. Furthermore, the combination of various plyometric exercises and the bilateral and unilateral jumps could improve these performances more than the use of single plyometric drills or traditional PT. Thus, the present review shows a greater effect of PT alone on jump and sprint (30 m sprint performance only) performances than the combination of PT with sprint/strength training. Although many issues related to PT remain to be resolved, the results presented in this review allow recommending the use of well-designed and sport-specific PT as a safe and effective training modality for improving jumping and sprint performance as well as agility in team sport athletes.

13.
Biol. Res ; 49: 1-12, 2016. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-950849

RESUMO

BACKGROUND: Disturbance of the equilibrium between reactive oxygen species (ROS) and anti-oxidants (AOX) has been implicated in various diseases, including atherosclerosis, the most common pathologic process underlying coronary heart disease (CHD). Thus, the defense systems against ROS are critical protecting blood vessel walls against oxidative damage. In this study, we investigate whether Ala16Val MnSOD and Pro198Leu GPx polymorphisms are associated with CHD susceptibility and/or severity. METHODS: Both polymorphisms were genotyped in a sample of 203 controls and 164 patients. CHD risk and severity, antioxidant status (enzymatic and/or non enzymatic) and biochemical parameters were assessed and analysed by genotype. RESULTS: A significant association of MnSOD variant to CHD risk was revealed in males. Males harboring the Val/Val genotype were approximately at twofold increased risk of CHD compared to controls (Ala carriers vs Val/Val, adjusted OR 1.89; 95 % CI 1.18-3.42, p = 0.03). Significant decreases in SOD activity and total antioxidant status (TAS) were observed in Val carriers and by CHD status. Whereas, no association of GPx variant genotype (Leu/Leu) and activity to cardiopathy events was discerned. CHD severity, as demonstrated by the number of vessel stenosis, was associated with significantly higher frequency of Val allele and LDL levels in CHD subjects. CONCLUSIONS: Our results showed a lack of association of Pro198Leu GPx polymorphism to CHD risk and severity. However, they suggest that Ala16Val MnSOD polymorphism and decreased antioxidant defences are likely contributed to CHD risk in Tunisian men. Furthermore, the Val encoding MnSOD allele and decreased SOD activity were significantly correlated with CHD stenosis progression


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Polimorfismo Genético , Superóxido Dismutase/genética , Doença das Coronárias/genética , Glutationa Peroxidase/genética , Fatores de Tempo , Tunísia , Índice de Gravidade de Doença , Estudos de Casos e Controles , Reação em Cadeia da Polimerase , Fatores de Risco , Análise de Variância , Medição de Risco , Estresse Oxidativo , Doença das Coronárias/patologia , Genótipo
14.
Theor Biol Med Model ; 12: 23, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26541955

RESUMO

BACKGROUND: DNA double-strand breaks (DSBs) are highly cytotoxic and mutagenic. MRE11 plays an essential role in repairing DNA by cleaving broken ends through its 3' to 5' exonuclease and single-stranded DNA endonuclease activities. METHODS: The present study aimed to in silico characterization and molecular modeling of MRE11 from Phoenix dactylifera L cv deglet nour (DnMRE11) by various bioinformatic approaches. To identify DnMRE11 cDNA, assembled contigs from our cDNA libraries were analysed using the Blast2GO2.8 program. RESULTS: The DnMRE11 protein length was 726 amino acids. The results of HUMMER show that DnMRE11 is formed by three domains: the N-terminal core domain containing the nuclease and capping domains, the C-terminal half containing the DNA binding and coiled coil region. The structure of DnMRE11 is predicted using the Swiss-Model server, which contains the nuclease and capping domains. The obtained model was verified with the structure validation programs such as ProSA and QMEAN servers for reliability. Ligand binding studies using COACH indicated the interaction of DnMRE11 protein with two Mn(2+) ions and dAMP. The ConSurf server predicted that residues of the active site and Nbs binding site have high conservation scores between plant species. CONCLUSIONS: A model structure of DnMRE11 was constructed and validated with various bioinformatics programs which suggested the predicted model to be satisfactory. Further validation studies were conducted by COACH analysis for active site ligand prediction, and revealed the presence of six ligands binding sites and two ligands (2 Mn(2+) and dAMP).


Assuntos
Simulação por Computador , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Modelos Moleculares , Phoeniceae/química , Proteínas de Plantas/química , Sítios de Ligação , Família Multigênica , Proteínas de Plantas/genética , Estrutura Terciária de Proteína , Análise de Sequência de Proteína , Software , Homologia Estrutural de Proteína
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