Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Clin Case Rep ; 12(4): e8689, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38550740

RESUMEN

Focal atrial tachycardia (FAT) is an organized atrial rhythm >100 beats per minute initiated from a discrete origin and spreading over both atria in a centrifugal pattern. The arrhythmia may be sustained or incessant. Dynamic forms with recurrent interruptions and reinitiating may be frequent. In this report, we present a 36-year-old man who came to the emergency room complaining of palpitation and shortness of breath. All laboratory evaluations were normal. With an initial electrocardiogram (ECG) the patient was admitted with the initial diagnosis of atrial flutter. Finally, after the electrophysiologist's examination, with the diagnosis of FAT, ablation was successfully performed. Atrial tachycardia (AT), excluding atrial fibrillation (AF) and cavotricuspid isthmus-dependent atrial flutter (AFL), account for 10% of supraventricular tachycardia referred for ablation procedures. More than 70% of these cases are focal and occur in patients with no records of cardiac surgery or ablation of AF. FAT originating from the right pulmonary veins (PV) can be challenging to differentiate from atrial flutter due to their proximity and overlapping symptoms. The right PV is close to the right atrium, and the abnormal electrical activity in FAT may mimic the organized circuit found in atrial flutter. Distinguishing between FAT and atrial flutter is crucial for choosing the best therapeutic option. This can be done most of the time by focusing on the differences in the pattern of their P and QRS waves, R-R wave intervals, and also their baseline changes on ECG, as well as their cycle duration, response to adenosine and risk factors of the patient.

2.
Food Sci Nutr ; 11(2): 696-708, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36789048

RESUMEN

Ursolic acid (UA) mediates the vasorelaxant activity via nitric oxide (NO) release, and upregulation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) in disease conditions with increased oxidative stress (OS). The present study aimed to reflect on the impact of 8 weeks of a combination of UA supplementation and resistance/endurance training in old male Wistar rats having a high-fat diet and/or low-dose streptozotocin-induced type 2 diabetes (HFD/STZ-induced T2D), with an emphasis on Sirtuin 1 (SIRT1)-endothelial nitric oxide synthase (eNOS) axis and OS indices in their aortic tissues. A total number of56 21-month-old male Wistar rats with HFD/STZ-induced T2D were randomized into seven groups (n = eight animals per group): (1) sedentary old nondiabetic (Control [C]); (2) sedentary HFD/STZ-induced T2D (Diabetic [D]); (3) sedentary HFD/STZ-induced T2D plus UA (Diabetic + Ursolic Acid [DU]); (4) endurance-trained HFD/STZ-induced T2D (Diabetic + Endurance Training [DE]); (5) resistance-trained HFD/STZ-induced T2D (Diabetic + Resistance Training [DR]); (6) endurance-trained HFD/STZ-induced T2D plus UA (Diabetic + Endurance Training + Ursolic Acid [DEU]); and (7) resistance-trained STZ-diabetic plus UA (Diabetic + Resistance Training + Ursolic Acid [DRU]) rats. The ladder-based resistance training group performed the ladder resistance training at 60% of the maximum voluntary carrying capacity (MVCC), 14-20 climbs in each session, with a one-min rest between each two trials, 5 days a week. The treadmill-based endurance exercise training protocol consisted of repeated bouts of high- and low-intensity training with 60-75% maximal running speed and 30%-40% maximal running speed in the course of 8 weeks, respectively. The animals in the supplement groups also took 500 mg of UA/kg of high-fat diet/day, resulting in a daily UA intake of approximately 250 mg UA per kg of body weight rat/day. The resistance/endurance training plus the UA consumption could partially reverse the levels of malondialdehyde (MDA), nitric oxide (NO), as well as total antioxidant capacity (TAC). It was concluded that oral 0.5% UA supplementation can prevent vascular aging biomarkers in a HFD/STZ-induced T2D model. Further studies are also required to clarify how chronic consumption of UA with/without training protocols reverses vascular aging process.

3.
Int J Biol Macromol ; 233: 123407, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36708896

RESUMEN

Protein folding is a biophysical process by which proteins reach a specific three-dimensional structure. The amino acid sequence of a polypeptide chain contains all the information needed to determine the final three-dimensional structure of a protein. When producing a recombinant protein, several problems can occur, including proteolysis, incorrect folding, formation of inclusion bodies, or protein aggregation, whereby the protein loses its natural structure. To overcome such limitations, several strategies have been developed to address each specific issue. Identification of proper protein refolding conditions can be challenging, and to tackle this high throughput screening for different recombinant protein folding conditions can prove a sound solution. Different approaches have emerged to tackle refolding issues. One particular approach to address folding issues involves molecular chaperones, highly conserved proteins that contribute to proper folding by shielding folding proteins from other proteins that could hinder the process. Proper protein folding is one of the main prerequisites for post-translational modifications. Incorrect folding, if not dealt with, can lead to a buildup of protein misfoldings that damage cells and cause widespread abnormalities. Said post-translational modifications, widespread in eukaryotes, are critical for protein structure, function and biological activity. Incorrect post-translational protein modifications may lead to individual consequences or aggregation of therapeutic proteins. In this review article, we have tried to examine some key aspects of recombinant protein expression. Accordingly, the relevance of these proteins is highlighted, major problems related to the production of recombinant protein and to refolding issues are pinpointed and suggested solutions are presented. An overview of post-translational modification, their biological significance and methods of identification are also provided. Overall, the work is expected to illustrate challenges in recombinant protein expression.


Asunto(s)
Chaperonas Moleculares , Pliegue de Proteína , Proteínas Recombinantes/metabolismo , Chaperonas Moleculares/metabolismo , Procesamiento Proteico-Postraduccional , Proteolisis
5.
J Fluoresc ; 32(6): 2129-2137, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35947332

RESUMEN

In the present work, CdTe/ZnS high luminescence quantum dots (QDs) were synthesized by a facile, fast, one-pot, and room temperature photochemical method. Synthesized QDs were characterized by different structural and optical analyses such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), Raman, photoluminescence (PL) and UV-visible (UV-vis) spectroscopies. The results confirmed the successful growth of the ZnS shell and formation of CdTe/ZnS core/shell structure. CdTe/ZnS prepared QDs indicated a PL quantum yield of about 51%. These high luminescence QDs were used for detection of Hg2+ ions in aqueous media, as catalyst for photodegradation of different organic dyes, and as antibacterial material for the inhibition of bacterial growth. PL intensity of the CdTe/ZnS QDs was completely quenched after addition of 1 m molar Hg2+in to the media. Photocatalyst activity of CdTe/ZnS QDs was studied by rhodamine b, methylene blue, and methylene orange as organic dyes under both the sun and UV illuminations, and results showed that CdTe/ZnS QDs had the best photocatalyst activity for methylene blue degradation under UV irradiation and radical scavenger results indicated that electrons have a main role in photodegradation of methylene blue dye by CdTe/ZnS QDs under UV illumination. Antibacterial effects of CdTe/ZnS QDs evaluated by Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) methods against two strains of bacteria. The results of the antibacterial test showed that CdTe/ZnS could inhibit bacterial growth in Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative G) bacteria.


Asunto(s)
Compuestos de Cadmio , Mercurio , Puntos Cuánticos , Puntos Cuánticos/química , Compuestos de Cadmio/farmacología , Compuestos de Cadmio/química , Telurio/química , Mercurio/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Azul de Metileno , Compuestos de Zinc/química , Sulfuros/farmacología , Sulfuros/química , Agua/química , Antibacterianos/farmacología , Antibacterianos/análisis , Escherichia coli , Colorantes/análisis
6.
Environ Sci Pollut Res Int ; 29(22): 33713-33724, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35029822

RESUMEN

Heat- and pH-stable phytase efficiently hydrolyzes phytic acid. In this research, heat- and pH-stable mutant phytases, T83R, L287R, and T83R/L287R were generated by site-directed mutagenesis from Yersinia intermedia. After the induction and expression of recombinant wild-type and mutant phytases in E. coli BL21, the enzymes were purified using nickel sepharose affinity chromatography, and characterized kinetically and thermodynamically using spectroscopy methods. The mutants showed optimum activity at pH 5.15 and 55-61 °C. The catalytic efficiencies of T83R, L287R, T83R/L287R, and wild-type phytases were calculated to be 2941, 29346, 4906, and 6917 mmol/L-1s-1, respectively. Moreover, after the incubation of T83R, L287R, wild-type, and T83R/ L287R phytases at 100 °C for 1 h, the enzymes retained 22, 5, 4, and 2% of their initial activities, respectively. In addition, T83R, T83R/L287R, L287R, and wild-type phytases retained 82, 44, 16 as well as 11% of their initial activities after 1 h at pH 5.15, respectively. Among these mutants, T83R mutant showed 18% increase in thermal stability, 71% increase in pH stability, and +0.103 KJ/mole increase in ΔΔG, while the catalytic efficiency and ΔΔG value of L287R mutant increased by 4 times and +0.0903 KJ/mole, respectively. Thus, the mutants have the potential to be used in feed industries to increase the bioavailability of minerals while decreasing soil and water pollution.


Asunto(s)
6-Fitasa , 6-Fitasa/química , Estabilidad de Enzimas , Escherichia coli/metabolismo , Concentración de Iones de Hidrógeno , Yersinia/química
7.
Iran J Allergy Asthma Immunol ; 20(4): 441-452, 2021 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-34418898

RESUMEN

Some antimicrobial peptides (AMPs), microRNAs (miRs), and Toll-like receptor 4 (TLR-4) are involved in autoimmune diseases, which may be affected by exercise training. The purpose of this study was to investigate the effect of an eight-week combined exercise training (aerobic and resistance) on the expression of inflammatory factors, including, human beta-defensin-2 (hBD-2), cathelicidin (LL-37), TLR-4, miR-23b, miR-155, and miR-326 in women with relapsing and remitting multiple sclerosis (RRMS), which has not been investigated yet. Twenty-three women (20-40 years) with RRMS were randomized into the combined training (CT) and control (CON) groups. The CT group subjects completed eight weeks of supervised CT using a treadmill and stationary bicycle for aerobic exercise and weight machines for resistance exercise. The expression levels of hBD-2, LL-37, TLR-4, miR-23b, miR-155, and miR-326 were measured by real-time polymerase chain reaction (RT-PCR) at the baseline and end of the study. Although the expression of hBD-2 and miR-23b decreased in both CT and CON groups, the reduction was lower in the CT group than in the CON group (p=0.001). The expression of LL-37 in the CT group remained unchanged, but that of the CON group increased; thus, the between-group difference was significant. Although the TLR-4, miR-155, and miR-326 expression increased in both groups compared to the baseline, the increase in the CT group was lower than the CON group. Our results showed that the combined training might improve inflammatory symptoms by affecting the expression of some AMPs, miRs, and TLR-4 in patients with relapsing and remitting multiple sclerosis.


Asunto(s)
Péptidos Antimicrobianos/genética , Ejercicio Físico , Regulación de la Expresión Génica , MicroARNs/genética , Esclerosis Múltiple/genética , Receptor Toll-Like 4/genética , Adulto , Biomarcadores , Estudios de Casos y Controles , Citocinas/metabolismo , Susceptibilidad a Enfermedades , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Masculino , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple Recurrente-Remitente/genética , Esclerosis Múltiple Recurrente-Remitente/metabolismo , Receptor Toll-Like 4/metabolismo , Adulto Joven
8.
Colloids Surf B Biointerfaces ; 206: 111964, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34229174

RESUMEN

Designing a sensitive method for the detection of streptomycin residues in animal products is essential for controlling consumer health risk. In this study, a high-purity pencil lead graphite electrode coated with inner graphene layers and outer surface-adsorbed gold nanoparticles attached to streptomycin-specific thiolated aptamer was used as an electrochemical aptasensor. The aptasensor electrode fabrication steps were investigated by scanning electron microscope (SEM) and Fourier-transform infrared spectrophotometer (FTIR). Moreover, aptasensor performance during fabrication and binding of aptamer to streptomycin were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. After the binding of sreptomycin to it's specific aptamer as a component of the aptasensor a decrease in the current and an increase in the charge transfer resistance (Rct) were recorded using the above-mentioned techniques. Under optimal conditions, the novel ultra-sensetive designed aptansensor detects streptomycin in the range of 10-8 to 10-16 M with a LOD of 0.8×10-18 M. The aptansensor demonstrates a high selectivity, good reproducibility and acceptable stability for the specific detection of streptomycin. According to the results, the manufactured aptansensor is a fast, low-cost, highly sensitive and selective device and thus the aptasensor can detect the trace amounts of streptomycin in milk in dairy industries.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Grafito , Nanopartículas del Metal , Animales , Técnicas Electroquímicas , Electrodos , Oro , Leche , Reproducibilidad de los Resultados , Estreptomicina
9.
Bioprocess Biosyst Eng ; 44(10): 2217-2228, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34142205

RESUMEN

Phytase is used in poultry diets to hydrolyze and release of phytate-bound phosphorus. Immobilization on nanomaterials optimizes enzyme's thermal stability and reusability. This study aimed to immobilize the recombinant phytase from Yersinia intermedia on the surface of amino-multi-walled carbon nanotubes (amino-MWCNTs) by physical adsorption. For this, zeta potential measurement, FTIR spectroscopic analysis, scanning electron microscope (SEM), kinetic as well as thermodynamic parameters were used to characterize immobilized phytase on amino-MWCNTs. According to results, the optimum temperature of the immobilized phytase increased from 50 to 70 °C and also thermal and pH stability improved considerably. Moreover, immobilization led to an increase in the value of Km and kcat from 0.13 to 0.33 mM and 2220 to 2776 s-1, respectively. In addition, the changes in activation energy of thermal inactivation (ΔE#a (D)), the free energy of thermal inactivation (ΔG#D) and the enthalpy of thermal inactivation (ΔH#D) for immobilized phytase increased by +11.05, +24.7 and +11.4 kj/mole, respectively, while the value of the change in the entropy of thermal inactivation (ΔS#D) decreased by - 0.04 kj/mole.K. Overall, our results showed that adsorption immobilization of phytase on amino-MWCNTs increases thermal, pH and storage stability as well as some of kinetic parameters.


Asunto(s)
6-Fitasa/metabolismo , Nanotubos de Carbono/química , Yersinia/enzimología , 6-Fitasa/aislamiento & purificación , Adsorción , Estabilidad de Enzimas , Cinética , Microscopía Electrónica de Rastreo , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica
10.
Colloids Surf B Biointerfaces ; 204: 111774, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33932893

RESUMEN

A variety of organic nanomaterials and organic polymers are used for enzyme immobilization to increase enzymes stability and reusability. In this study, the effects of the immobilization of enzymes on organic and organic-inorganic hybrid nano-supports are compared. Immobilization of enzymes on organic support nanomaterials was reported to significantly improve thermal, pH and storage stability, acting also as a protection against metal ions inhibitory effects. In particular, the effects of enzyme immobilization on reusability, physical, kinetic and thermodynamic parameters were considered. Due to their biocompatibility with low health risks, organic support nanomaterials represent a good choice for the immobilization of enzymes. Organic nanomaterials, and especially organic-inorganic hybrids, can significantly improve the kinetic and thermodynamic parameters of immobilized enzymes compared to macroscopic supports. Moreover, organic nanomaterials are more environment friendly for medical applications, such as prodrug carriers and biosensors. Overall, organic hybrid nanomaterials are receiving increasing attention as novel nano-supports for enzyme immobilization and will be used extensively.


Asunto(s)
Enzimas Inmovilizadas , Nanoestructuras , Biocatálisis , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Cinética
11.
Colloids Surf B Biointerfaces ; 203: 111747, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33839476

RESUMEN

Fenneropenaeus merguiensis (commonly named banana shrimp) is one of the most important farmed crustacean worldwide species for the fisheries and aquaculture industry. Besides its nutritional value, it is a good source of chitinase, an enzyme with excellent biological and catalytic properties for many industrial applications. In the present study, a putative chitinase-encoding cDNA was synthesized from mRNA from F. merguiensis hepatopancreas tissue. Subsequently, the corresponding cDNA was cloned, sequenced and functionally expressed in Escherichia coli, and the recombinant F. merguiensis chitinase (rFmCHI) was purified by His-tag affinity chromatography. The bioinformatics analysis of aminoacid sequence of rFmCHI displayed a cannonical multidomain architecture in chitinases which belongs to glycoside hydrolase family 18 (GH18 chitinase). Biochemical characterization revealed rFmCHI as a monomeric enzyme of molecular weight 52 kDa with maximum activity at 40 °C and pH 6.0 Moreover, the recombinant enzyme is also stable up to 60 °C, and in the pH range 5.0-8.0. Steady-state kinetic studies for colloidal chitin revealed KM, Vmax and kcat values of 78.18 µM, 0.07261 µM. min-1 and 43.37 s-1, respectively. Overall, our results aim to demonstrate the potential of rFmCHI as suitable catalyst for bioconversion of chitin waste.


Asunto(s)
Quitinasas , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos , Secuencia de Bases , Quitina , Quitinasas/genética , Quitinasas/metabolismo , Cinética , Penaeidae/enzimología
12.
Biomed Pharmacother ; 137: 111363, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33582450

RESUMEN

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of COVID-19, is reported to increase the rate of mortality worldwide. COVID-19 is associated with acute respiratory symptoms as well as blood coagulation in the vessels (thrombosis), heart attack and stroke. Given the requirement of angiotensin converting enzyme 2 (ACE2) receptor for SARS-CoV-2 entry into host cells, here we discuss how the downregulation of ACE2 in the COVID-19 patients and virus-induced shift in ACE2 catalytic equilibrium, change the concentrations of substrates such as angiotensin II, apelin-13, dynorphin-13, and products such as angiotensin (1-7), angiotensin (1-9), apelin-12, dynorphin-12 in the human body. Substrates accumulation ultimately induces inflammation, angiogenesis, thrombosis, neuronal and tissue damage while diminished products lead to the loss of the anti-inflammatory, anti-thrombotic and anti-angiogenic responses. In this review, we focus on the viral-induced imbalance between ACE2 substrates and products which exacerbates the severity of COVID-19. Considering the roadmap, we propose multiple therapeutic strategies aiming to rebalance the products of ACE2 and to ameliorate the symptoms of the disease.


Asunto(s)
Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19 , Comunicación Paracrina , SARS-CoV-2 , COVID-19/metabolismo , COVID-19/fisiopatología , COVID-19/virología , Descubrimiento de Drogas , Humanos , Comunicación Paracrina/efectos de los fármacos , Comunicación Paracrina/fisiología , SARS-CoV-2/patogenicidad , SARS-CoV-2/fisiología , Índice de Severidad de la Enfermedad
13.
Int J Biol Macromol ; 168: 708-721, 2021 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-33232698

RESUMEN

Despite the widespread use in various industries, enzyme's instability and non-reusability limit their applications which can be overcome by immobilization. The nature of the enzyme's support material and method of immobilization affect activity, stability, and kinetics properties of enzymes. Here, we report a comparative study of the effects of inorganic support materials on immobilized enzymes. Accordingly, immobilization of enzymes on nanoinorganic support materials significantly improved thermal and pH stability. Furthermore, immobilizations of enzymes on the materials mainly increased Km values while decreased the Vmax values of enzymes. Immobilized enzymes on nanoinorganic support materials showed the increase in ΔG value, and decrease in both ΔH and ΔS values. In contrast to weak physical adsorption immobilization, covalently-bound and multipoint-attached immobilized enzymes do not release from the support surface to contaminate the product and thus the cost is decreased while the product quality is increased. Nevertheless, nanomaterials can enter the environment and increase health and environmental risks and should be used cautiously. Altogether, it can be predicated that hybrid support materials, directed immobilization methods, site-directed mutagenesis, recombinant fusion protein technology, green nanomaterials and trailor-made supports will be used increasingly to produce more efficient immobilized industrial enzymes in near future.


Asunto(s)
Enzimas Inmovilizadas/química , Mutagénesis Sitio-Dirigida , Nanoestructuras/química , Adsorción , Estabilidad de Enzimas , Enzimas Inmovilizadas/genética , Cinética , Termodinámica
14.
Biochim Biophys Acta Proteins Proteom ; 1868(2): 140312, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31740412

RESUMEN

Global economic growth often leads to depletion of raw materials and generation of greenhouse gases, as industry manufactures goods at ever increasing levels to keep up with the demand. The currently implemented production processes mostly rely on non-renewable resources, they suffer from high energy consumption, and generate waste that often has a negative environmental impact. Eco-friendly production methods are therefore intensely searched for. Among them, enzyme-based processes are appealing, because of their high substrate and reaction specificity and the relatively mild operation conditions required by these catalysts. In addition, renewable raw materials that allow sustainable production processes are also widely explored. Marine xylanases, which catalyze the hydrolysis of xylan, the major component of lignocellulose, are promising biocatalysts. Since they are produced by microorganisms that thrive in a wide variety of environmental conditions, the enzymes may be active at widely different ranges of pH, temperature, and salt concentrations. These properties are important for their successful application in various industrial processes, such as production of bioethanol, bleaching of paper and pulp, and in the food and feed sector. The present work gives a brief overview of marine sources of xylanases, their classification and features, and of the potential applications of these marine enzymes, especially in sustainable processes in the scope of circular economy.


Asunto(s)
Endo-1,4-beta Xilanasas/metabolismo , Blanqueadores/química , Blanqueadores/metabolismo , Endo-1,4-beta Xilanasas/clasificación , Concentración de Iones de Hidrógeno , Cinética , Lignina/metabolismo , Probióticos , Energía Renovable , Algas Marinas/enzimología
15.
Horm Mol Biol Clin Investig ; 38(2)2019 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-31063458

RESUMEN

Background Skeletal muscle is very sensitive to extracellular and intracellular signaling evoked by contractions from endurance and resistance exercise. The aim of this study was to compare the effects of moderate- and high-intensity endurance and resistance training on the serum myostatin (MSTN) and insulin-like growth factor (IGF-1) levels in older rats. Materials and methods Fifty old Wistar male rats (23 months old) were randomly divided into four experimental and one control groups, including moderate-endurance training (MET) (n = 10), high-intensity endurance training (EHT) (n = 10), moderate-intensity resistance training (MRT) (n = 10), high-intensity resistance training (HRT) (n = 10), and control group (C) (n = 10). Seventy-two hours after the last exercise session, euthanasia of the rats were rendered unconscious and direct blood samples were collected. Serum IGF-1 and MSTN concentration were measured using the enzyme-linked immuno sorbent assay (ELISA) method. The statistical analysis was performed using one-way analysis of variance (ANOVA) test with a significance level of p ≤ 0.05. Results There was a significant reduction in MSTN and an increase in IGF-1 concentrations was observed between IGF-I levels in high and moderate resistance and endurance training. However, no significant difference was observed in MSTN levels between groups. Discussion Therefore, it appears that resistance training, especially HRT, is effective to increase growth mediators among older rats.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/metabolismo , Miostatina/sangre , Condicionamiento Físico Animal , Animales , Masculino , Contracción Muscular , Ratas , Ratas Wistar
16.
Int J Biol Macromol ; 134: 216-222, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31059739

RESUMEN

The increasing use of nanoparticles in various industries has triggered the need to study their interconnection with biological macromolecules. The goal of this study was to survey the SiO2-nanoparticles efficacy on the thermal denaturation, conformation and activity of elastase at three temperatures of 303, 313 and 323K in the Tris buffer at pH of 8.5. In this work, distinct techniques such as UV-vis Spectrophotometry, Spectrofluorometry, and circular dichroism were employed. The fluorescence studies showed that SiO2 nanoparticles extremely reduced the intensity of elastase with the static mechanism. Thermodynamic parameter analysis also indicated that the process of binding of SiO2-nanoparticles to elastase was spontaneous, thereby suggesting that van der Waals forces or hydrogen bonding interactions played a key role in determining the complex stability. Far-UV circular dichroism studies further revealed that SiO2 nanoparticles could cause 9.79% reduction in the content of the α-helix and 3.24% increase in the content of the ß-sheet. Furthermore, kinetic parameters (Vmax and Kcat/Km) indicated that SiO2 nanoparticles had an activation effect on the elastase activity. Melting temperature studies at the selected concentration of SiO2 nanoparticles also showed that by adding SiO2 nanoparticles, elastase thermal stability was slightly increased. Overall, these nanoparticles modified the structure of the elastase, ultimately changing the activity and stability of this enzyme.


Asunto(s)
Nanopartículas , Elastasa Pancreática/metabolismo , Dióxido de Silicio/química , Dióxido de Silicio/metabolismo , Animales , Estabilidad de Enzimas , Cinética , Unión Proteica , Análisis Espectral , Porcinos , Temperatura
17.
Appl Microbiol Biotechnol ; 102(23): 9937-9948, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30276711

RESUMEN

Chitinolytic enzymes are capable to catalyze the chitin hydrolysis. Due to their biomedical and biotechnological applications, nowadays chitinolytic enzymes have attracted worldwide attention. Chitinolytic enzymes have provided numerous useful materials in many different industries, such as food, pharmaceutical, cosmetic, or biomedical industry. Marine enzymes are commonly employed in industry because they display better operational properties than animal, plant, or bacterial homologs. In this mini-review, we want to describe marine chitinolytic enzymes as versatile enzymes in different biotechnological fields. In this regard, interesting comments about their biological role, reaction mechanism, production, functional characterization, immobilization, and biotechnological application are shown in this work.


Asunto(s)
Biotecnología , Quitinasas/metabolismo , Océanos y Mares , Archaea/enzimología , Bacterias/enzimología , Quitina/química , Quitinasas/antagonistas & inhibidores , Cianobacterias/enzimología , Enzimas Inmovilizadas/antagonistas & inhibidores , Enzimas Inmovilizadas/metabolismo , Hongos/enzimología , Microalgas/enzimología , Ingeniería de Proteínas , Proteínas Recombinantes/biosíntesis , Microbiología del Agua
18.
Horm Metab Res ; 50(6): 441-452, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29883971

RESUMEN

Fibroblast growth factors (FGFs) are responsible for the regulation of a wide range of biological functions, among which cellular proliferation, survival, migration, and differentiation could be pointed out. FGF19 controls the enterohepatic bile acid/cholesterol system, and FGF21 modulates fatty acid/glucose metabolism. Obesity, type 2 diabetes, coronary artery disease, and cancer, all can alter FGF21 circulating concentrations. In contrast to FGF21, metabolic diseases exhibit reduced serum FGF19 levels. Accordingly, FGF19 and FGF21 play important roles in regulating glucose and lipid metabolism. Hence, we present here a timely review on the relationship between FGF19/21 and metabolic diseases, especially obesity, and their probable role in development and treatment of obesity seems necessary.


Asunto(s)
Factores de Crecimiento de Fibroblastos/uso terapéutico , Enfermedades Metabólicas/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Animales , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Humanos
19.
Arch Biochem Biophys ; 650: 39-48, 2018 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-29758202

RESUMEN

Ursolic Acid (UA), a pentacyclic triterpenoid compound, plays a vital role in aging process. However, the role of UA in the regulation of aging and longevity is still controversial as we have previously demonstrated that UA increases SIRT1 protein level in aged-mice. Here, we reveal that UA directly activates SIRT1 in silico, in vitro and in vivo. We have identified that UA binds to outer surface of SIRT1 and leads to tight binding of substrates to enzyme in comparison with Resveratrol (RSV) and control. Furthermore, our results indicate that UA drives the structure of SIRT1 toward a closed state (an active form of enzyme). Interestingly, our experimental findings are in agreement with the molecular dynamic results. Based on our data, UA increases the affinity of enzyme for both substrates with decreasing Km value, while enhances the Vmax of enzyme. Additionally, we have determined that UA heightened SIRT1 catalytic efficiency by 2 folds compared with RSV. Thereby, to identify the endogenous activator of SIRT1, UA was administrated to aged-mice and then the tissues were isolated. According to our results, it can be concluded that UA increases SIRT1 activity and mimics Lamin A and AROS behavior in the living cells.


Asunto(s)
Activadores de Enzimas/farmacología , Sirtuina 1/metabolismo , Triterpenos/farmacología , Sitio Alostérico/efectos de los fármacos , Animales , Activación Enzimática/efectos de los fármacos , Humanos , Lamina Tipo A/metabolismo , Masculino , Ratones Endogámicos C57BL , Simulación del Acoplamiento Molecular , Conformación Proteica/efectos de los fármacos , Sirtuina 1/química , Ácido Ursólico
20.
Extremophiles ; 22(3): 335-346, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29442247

RESUMEN

Thermostable proteases are important in biotechnological and industrial sectors, due to their stability against denaturing agents and chemicals. The feature that gives them such unique applicability is their reaction at high temperatures, which affords a high concentration of substrate, and less risk of microbial contamination. Nearly 65% of industrial proteases are isolated from marine microbial source, and they can significantly resist a wide range of organic solvents at high temperatures. The most important trait of marine organisms is their adaptability, which allows them to grow optimally in harsh environments such as high salt, temperatures, and pressure-the characteristics of deep-sea hot springs and geothermal sediments. However, proteases are immunogenic, and they can trigger inflammatory conditions in human; so their safety assessment prior to industrial usage is of paramount importance. This review focusses on marine-origin thermophilic proteases, their thermal resistance, scopes of their industrial applications, and risks.


Asunto(s)
Organismos Acuáticos/enzimología , Proteínas Arqueales/metabolismo , Proteínas Bacterianas/metabolismo , Microbiología Industrial/métodos , Péptido Hidrolasas/metabolismo , Termotolerancia , Proteínas Arqueales/química , Proteínas Arqueales/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Estabilidad de Enzimas , Péptido Hidrolasas/química , Péptido Hidrolasas/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...