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1.
Int J Biol Macromol ; 263(Pt 1): 130688, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38458294

RESUMEN

This study reports the rational engineering of the S1' substrate-binding pocket of a thermally-stable keratinase from Pseudomonas aeruginosa 4-3 (4-3Ker) to improve substrate specificity to typical keratinase (K/C > 0.5) and catalytic activity without compromising thermal stability for efficient keratin degradation. Of 10 chosen mutation hotspots in the S1' substrate-binding pocket, the top three mutations M128R, A138V, and V142I showing the best catalytic activity and substrate specificity were identified. Their double and triple combinatorial mutants synergistically overcame limitations of single mutants, fabricating an excellent M128R/A138V/V142I triple mutant which displayed a 1.21-fold increase in keratin catalytic activity, 1.10-fold enhancement in keratin/casein activity ratio, and a 3.13 °C increase in half-inactivation temperature compared to 4-3Ker. Molecular dynamics simulations revealed enhanced flexibility of critical amino acid residues at the substrate access tunnel, improved global protein rigidity, and heightened hydrophobicity within the active site likely underpinned the increased catalytic activity and substrate specificity. Additionally, the triple mutant improved the feather degradation rate by 32.86 % over the wild-type, far exceeding commercial keratinase in substrate specificity and thermal stability. This study exemplified engineering a typical keratinase with enhanced substrate specificity, catalytic activity, and thermal stability from thermally-stable 4-3Ker, providing a more robust tool for feather degradation.


Asunto(s)
Queratinas , Péptido Hidrolasas , Queratinas/metabolismo , Especificidad por Sustrato , Péptido Hidrolasas/metabolismo , Temperatura , Concentración de Iones de Hidrógeno
2.
Adv Sci (Weinh) ; 11(5): e2303264, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38044298

RESUMEN

Owing to the advancement of interdisciplinary concepts, for example, wearable electronics, bioelectronics, and intelligent sensing, during the microelectronics industrial revolution, nowadays, extensively mature wearable sensing devices have become new favorites in the noninvasive human healthcare industry. The combination of wearable sensing devices with bionics is driving frontier developments in various fields, such as personalized medical monitoring and flexible electronics, due to the superior biocompatibilities and diverse sensing mechanisms. It is noticed that the integration of desired functions into wearable device materials can be realized by grafting biomimetic intelligence. Therefore, herein, the mechanism by which biomimetic materials satisfy and further enhance system functionality is reviewed. Next, wearable artificial sensory systems that integrate biomimetic sensing into portable sensing devices are introduced, which have received significant attention from the industry owing to their novel sensing approaches and portabilities. To address the limitations encountered by important signal and data units in biomimetic wearable sensing systems, two paths forward are identified and current challenges and opportunities are presented in this field. In summary, this review provides a further comprehensive understanding of the development of biomimetic wearable sensing devices from both breadth and depth perspectives, offering valuable guidance for future research and application expansion of these devices.


Asunto(s)
Materiales Biomiméticos , Dispositivos Electrónicos Vestibles , Humanos , Biomimética , Electrónica , Biónica
3.
J Agric Food Chem ; 71(50): 20062-20072, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38078849

RESUMEN

Reactive oxygen species (ROS) are crucial for signal transduction and the maintenance of cellular homeostasis. However, superfluous ROS may engender chronic pathologies. Feather keratin is a promising new source of antioxidant peptides that can eliminate excess ROS and potentially treat oxidative stress-related diseases, but the underlying mechanisms have remained elusive. This study investigated the antioxidant effects and mechanisms against H2O2-induced oxidative damage in HepG2 cells of the two latest discovered antioxidant peptides, CRPCGPTP (CP-8) and ANSCNEPCVR (AR-10), first decrypted from feather keratin. The results revealed that CP-8 and AR-10 did not exhibit cytotoxicity to HepG2 cells while reducing intracellular ROS accumulation. Simultaneously, they enhanced the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), thus alleviating H2O2-induced cell apoptosis. Molecular docking analysis demonstrated that CP-8, AR-10 interacted well with the key amino acids in the Kelch domain of Keap1, thereby directly disrupting the Keap1-Nrf2 interaction. The peptides' biosafety and antioxidant activity via Keap1/Nrf2 signaling lay the groundwork for further animal studies and applications as functional food additives.


Asunto(s)
Antioxidantes , Factor 2 Relacionado con NF-E2 , Animales , Humanos , Antioxidantes/farmacología , Antioxidantes/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Peróxido de Hidrógeno/toxicidad , Peróxido de Hidrógeno/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Queratinas , Plumas , Células Hep G2 , Simulación del Acoplamiento Molecular , Estrés Oxidativo
4.
J Agric Food Chem ; 71(21): 8061-8070, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37161263

RESUMEN

Feather keratin is an underappreciated protein resource of high quality, with limited bioavailability, and it urgently requires eco-friendly methods to enhance its value. Here, we report on the preparation, purification, and identification of novel peptides with antioxidant and xanthine oxidase (XOD) inhibitory activities from fermented feather broth, using Bacillus licheniformis 8-4. Two peptides, namely, DLCRPCGPTPLA (DA-12) and ANSCNEPCVR (AR-10), displayed remarkable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities with half-maximal inhibitory concentrations (IC50) values of 0.048, 0.034, and 0.95, 0.84 mg/mL, respectively. These values exceed those of the previously reported feather keratin-derived antioxidant peptides. Another peptide, GNQQVHLQSQDM (GM-12), demonstrated XOD activity inhibition, with an IC50 value of 12.15 mg/mL, and it quenched the fluorescence of XOD. Furthermore, after simulating gastrointestinal digestion, DA-12, AR-10, and GM-12 retained their biological activities. Meanwhile, DA-12 and GM-12 showed an unexpected synergistic inhibition on XOD activity accompanied by fluorescence quenching. This study provides new insights into the potential applications of feather keratin, including functionalized feed with antioxidative and antigout (anti-hyperuricemia) activities.


Asunto(s)
Antioxidantes , Xantina Oxidasa , Animales , Antioxidantes/farmacología , Xantina Oxidasa/metabolismo , Plumas , Queratinas , Péptidos/farmacología
5.
Biomed Rep ; 18(6): 38, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37168651

RESUMEN

Hypertension is an important risk factor for cardiovascular and cerebrovascular disease-associated death. Hypertension and its complications are the main problems that have an impact on public health at present. A portion of adults with hypertension fail to meet the recommended blood pressure (BP) treatment goals, despite strict clinical management. Those individuals requiring at least three types of antihypertensive drugs to achieve their BP goal may be classified as patients with resistant hypertension (RH). Bioelectric technology is an emerging method that functions with the help of the human body's own bioelectric system. It is widely used in auxiliary examination, pain relief and organ function rehabilitation. Bioelectrical technology, as an effective treatment for RH, has developed rapidly in recent years and mainly includes renal sympathetic denervation, carotid baroreflex activation therapy, Traditional Chinese Medicine electroacupuncture and transcutaneous electrical nerve stimulation (TENS). The present review describes the pathogenesis of hypertension and provides an understanding of bioelectrical technology as a treatment. In particular, the development of the application of TENS in RH is introduced. The aim is to provide a basis for the clinical treatment of RH and a new idea for further clinical trials in this field.

6.
ACS Omega ; 8(8): 8092-8100, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36873023

RESUMEN

The zinc-air batteries (ZABs) are regarded as the most potential energy storage device for the next generation. However, the zinc anode passivation and hydrogen evolution reaction (HER) in alkaline electrolyte situations inhibit the zinc plate working efficiency, which needs to improve zinc solvation and better electrolyte strategy. In this work, we propose a design of new electrolyte by using a polydentate ligand to stabilize the zinc ion divorced from the zinc anode. The formation of the passivation film is suppressed greatly, compared to the traditional electrolyte. The characterization result presents that the quantity of the passivation film is reduced to nearly 33% of pure KOH result. Besides, triethanolamine (TEA) as an anionic surfactant inhibits the HER effect to improve the efficiency of the zinc anode. The discharging and recycling test indicates that the specific capacity of the battery with the effect of TEA is improved to nearly 85 mA h/cm2 compared to 0.21 mA h/cm2 in 0.5 mol/L KOH, which is 350 times the result of the blank group. The electrochemical analysis results also indicate that zinc anode self-corrosion is palliated. With density function theory, calculation results prove the new complex existence and structure in electrolytes by the data of the molecular orbital (highest occupied molecular orbital-lowest unoccupied molecular orbital). A new theory of multi-dentate ligand inhibiting passivation is elicited and provides a new direction for ZABs' electrolyte design.

7.
Food Chem X ; 17: 100593, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36845495

RESUMEN

Xanthine oxidase is an oxidase that has a molybdopterin structure with substrate inhibition. Here, we show that a single point mutation (Q201) in the Acinetobacter baumannii xanthine oxidase (AbXOD) obtained mutant Q201E (k cat =799.44 s-1, no inhibition) with high enzyme activity and decrease of substrate inhibition in 5 mmol/L high substrate model, and which cause two loops structure change at active center, characterized by complete loss of substrate inhibition without reduction of enzymatic activity. Molecular docking results showed that the change of flexible loop increased the affinity between substrate and enzyme, and the formation of a π-π bond and two hydrogen bonds made the substrate more stable in the active center. Ultimately, Q201E can still maintain better enzyme activity under high purine content (an approximately 7-fold improvement over the wild-type), indicating a broader application prospect in the manufacture of low-purine food.

8.
Mol Biotechnol ; 65(10): 1644-1652, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36737554

RESUMEN

Glutathione peroxidase (GPx) is an important antioxidant enzyme. Selenocysteine (Sec)-containing GPxs (Sec-GPxs) are usually superior to their conventional cysteine-containing counterparts (Cys-GPxs), which make up the majority of the natural GPxs but display unsuitable activity and stability for industrial applications. This study first heterologously expressed and characterized a Cys-GPx from Lactococcus lactis (LlGPx), systematically exchanged all the three Cys to Sec and introduced an extra Sec. The results showed that the insertion of Sec at the active site could effectively increase the enzyme activity and confer a lower optimal pH value on the mutants. The double mutant C36U/L157U increased by 2.65 times (5.12 U/mg). The thermal stability of the C81U mutant was significantly improved. These results suggest that site-directed Sec incorporation can effectively improve the enzymatic properties of LlGPx, which may be also used for the protein engineering of other industrial enzymes containing catalytic or other functional cysteine residues.


Asunto(s)
Biosíntesis de Proteínas , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Biocatálisis , Mutación , Dominio Catalítico , Ingeniería de Proteínas
9.
Minerva Anestesiol ; 89(6): 553-564, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36852570

RESUMEN

INTRODUCTION: Remimazolam is a novel sedative drug that has been successively approved for procedural sedation and general anesthesia, however, which has not been fully explored due to limited clinical studies and a small sample size. Current clinical studies have focused on the use of remimazolam and propofol for general anesthesia (GA) as indicators of safety outcomes in surgical patients, but different studies have reached different conclusions. The aim of this study was to investigate whether the safety-related outcome indicators in GA were superior to propofol in surgical patients. EVIDENCE ACQUISITION: We systematically searched PubMed, Cochrane Library, Embase, and Web of Science databases for all published randomized controlled trials comparing remimazolam with propofol for general anesthesia. Data from eligible studies were pooled with relative risk or mean differences to analyze the differences in hemodynamic stability and adverse effects of the two medications. EVIDENCE SYNTHESIS: Eight randomized controlled trials involving 998 participants were included. Compared with propofol, remimazolam had better hemodynamic stability with a lower incidence of hypotension (RR=0.43, 95% CI: [0.34, 0.55], I2=0%, P<0.00001), a higher preintubation, and immediate postintubation mean arterial pressure (MAP, MD=5.41, 95% CI: [5.26,11.24], Z=5.41, P<0.00001<0.05); (MD=1.60, 95% CI: [-0.20, 3.41], Z=1.74, P<0.08>0.05). Regarding other adverse events, the incidence of hypoxemia, nausea and vomiting, dizziness and injection site pain was lower in the remimazolam group compared to the propofol group. CONCLUSIONS: In this Meta-analysis, compared with propofol, remimazolam for GA reduced the incidence of hypotension, hypoxemia, nausea and vomiting, dizziness and injection site pain, and had a more stable MAP before and after intubation, which supported that remimazolam is a safer sedative. However, a large sample is needed to validate this finding.


Asunto(s)
Hipotensión , Propofol , Humanos , Propofol/efectos adversos , Mareo/inducido químicamente , Benzodiazepinas , Anestesia General/efectos adversos , Hipnóticos y Sedantes/efectos adversos , Dolor , Náusea , Vómitos , Hipotensión/inducido químicamente , Hipoxia , Ensayos Clínicos Controlados Aleatorios como Asunto
10.
J Appl Microbiol ; 134(2)2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36639131

RESUMEN

AIMS: Feathers are keratin-rich byproducts of poultry processing, but those are often frequently abandoned as garbage and thus polluting the environment. Therefore, the study focused on the efficient biodegradation, bioactivity, and high-value application of feather keratin. METHODS AND RESULTS: Feather-degrading bacteria were identified, and the degradation properties were characterized. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) and ABTS (2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid))radical scavenging assays, cytotoxicity assays, intracellular reactive oxygen scavenging assays, and cell migration assays were used to examine the biological activities of the feather keratin hydrolysis peptides (FKHPs). The results showed that we screened a feather-degrading strain of Bacillus licheniformis 8-4, which achieved complete degradation of 2% (w/v) feathers within 48 h. Notably, the feather fermentation broth was particularly high in FKHPs, which exhibited good DPPH and ABTS radical scavenging ability. Further studies revealed that FKHPs had both the ability to scavenge H2O2-induced ROS from HaCat cells and the ability to promote HaCat cell migration, while remaining non-toxic. CONCLUSIONS: The effective feather-degrading ability of B. licheniformis 8-4 allowed for the fermentation of feather medium to yield active peptides that were both antioxidants and cell-migration enhancers.


Asunto(s)
Bacillus licheniformis , Animales , Antioxidantes/química , Plumas/química , Plumas/metabolismo , Plumas/microbiología , Queratinas/metabolismo , Peróxido de Hidrógeno/metabolismo , Pollos , Péptidos/farmacología , Péptidos/química , Péptido Hidrolasas/metabolismo
12.
Environ Sci Pollut Res Int ; 30(2): 2480-2493, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35930154

RESUMEN

Feather biodegradation is an important premise for efficient resource development and utilization, in which keratinase plays an important role. However, there are few keratinases that combine the high activity, thermal stability, and organic solvent tolerance required for industrialization. This paper reported an efficient feather-degrading Pseudomonas aeruginosa 4-3 isolated from slaughterhouses. After 48 h of fermentation by P. aeruginosa 4-3 in a feather medium at 40 °C, pH 8.0, keratinase was efficiently produced (295.28 ± 5.42 U/mL) with complete feather degradation (95.3 ± 1.5%). Moreover, the keratinase from P. aeruginosa 4-3 showed high optimal temperature (55 °C), good thermal stability, wide pH tolerance, and excellent organic solvent resistance. In addition, P. aeruginosa 4-3-derived aminopeptidases also exhibit excellent thermal stability and organic solvent tolerance. Encouragingly, the reaction of crude keratinase and aminopeptidase with feathers for 8 h resulted in a 78% degradation rate of feathers. These properties make P. aeruginosa 4-3 keratinase and aminopeptidase ideal proteases for potential applications in keratin degradation, as well as provide ideas for the synergistic degradation of keratin by multiple enzymes.


Asunto(s)
Plumas , Aves de Corral , Animales , Plumas/química , Aminopeptidasas/análisis , Aminopeptidasas/metabolismo , Pseudomonas aeruginosa/metabolismo , Pollos/metabolismo , Péptido Hidrolasas/metabolismo , Queratinas/metabolismo , Concentración de Iones de Hidrógeno , Temperatura
13.
J Chromatogr A ; 1685: 463590, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36323111

RESUMEN

A reliable method for simultaneous determination of four organic selenium species by HPLC-ICP-MS was developed and implemented in determining organic selenoamino acids (Se-AAs) in selenoproteins from Lactococcus lactis (L. lactis) NZ9000. The method consisted of liberating Se-AAs from selenoproteins using ultrasound-assisted protease hydrolysis, and quantitatively detecting Se-AA speciations by HPLC-ICP-MS. After optimizations of proteolysis conditions, chromatographic conditions and determination conditions, the established method could efficiently separate the four Se-AAs, including SeCys, SeCys2, SeMeCys and SeMet within 10 min. It presented high sensitivity with the limits of detection and quantitation in the range of 0.197∼0.240 µg∙L-1 and 0.788∼0.960 µg∙L-1, respectively, good repeatability with a relative standard deviation (RSD) of less than 5%, and good recovery in the desired floating range of 90%∼105%, verifying the good accuracy. The method successfully detected four selenium species in the purified glutathione peroxidase (LlGPx) overexpressed in L. lactis NZ9000, SeCys (0.9716∼1.6784 µg∙g-1), SeCys2 (1.0695∼1.2124 µg∙g-1), SeMeCys (0.7288∼0.7984 µg∙g-1) and SeMet (1.0058∼1.9571 µg∙g-1), accounting for up to 80.14% of total selenium. There was no difference of order of magnitude in the four Se-AAs, indirectly indicating the random incorporation of selenium into selenoprotein LlGPx in L. lactis NZ9000. This work throws new light on the identification and biosynthesis of organic selenium species in selenoproteins and selenium-riched organisms like L. lactis.


Asunto(s)
Lactococcus lactis , Selenio , Cromatografía Líquida de Alta Presión/métodos , Lactococcus lactis/metabolismo , Selenio/análisis , Selenoproteínas , Espectrometría de Masas/métodos
14.
J Sci Food Agric ; 102(15): 7079-7086, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35690902

RESUMEN

BACKGROUND: With the increasing prevalence of gout and its etiological hyperuricemia, dietary control of gout based on low-purine food according to patients' eating habits is becoming a better choice compared to the existing drug treatment such as allopurinol with notorious side effects. Reconstructing the purine metabolic pathway in vitro to degrade purine substances in food into natural functional allantoin appears to be an innovative method for preparing nutritious and healthy food of low purine content. The present study reports a computer-assisted in vitro reconstruction of four purinolytic enzymes metabolizing adenosine into allantoin to reduce purine content in food for personalized dietary control of hyperuricemia and gout. RESULTS: Under the optimum reaction conditions of 40 °C and pH 7, 0.1 U of enzymes and 0.5 mmol L-1 adenosine determined by an orthogonal test design, 16 different enzyme complexes were experimentally tested. The tested enzyme composition and allantoin production values were used as input and output to build a three-layer back propagation artificial neural network (BP-ANN) model, which was further optimized by a genetic algorithm (GA). The optimum enzyme complex predicted by the GA-BP-ANN model produced 248.08±7.832 µmol L-1 allantoin, which was 19.9% higher than equimolar mixture of enzymes, and also more efficiently lowered purine contents in beer, as well as beef and yeast extracts. CONCLUSION: This is the first in vitro reconstitution of complete purine metabolic pathway by combining ANN and GA technologies, with successful application with respect to lowering the purine content in food, indicating a promising application of computer-assisted in vitro reconstitution of purinolytic pathway in low-purine food to prevent hyperuricemia and gout. © 2022 Society of Chemical Industry.


Asunto(s)
Gota , Hiperuricemia , Bovinos , Animales , Humanos , Alantoína , Purinas , Adenosina , Computadores
15.
Mol Biotechnol ; 64(11): 1270-1278, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35578070

RESUMEN

This study reported the cloning, expression, and characterization of a new salt-tolerant leucine dehydrogenase (PrLeuDH) from Pseudoalteromonas rubra DSM 6842. A codon-optimized 1038 bp gene encoding PrLeuDH was successfully expressed on pET-22b( +) in E. coli BL21(DE3). The purified recombinant PrLeuDH showed a single band of about 38.7 kDa on SDS-PAGE. It exhibited the maximum activity at 40 °C and pH 10.5, while kept high activities in the range of 25-45 °C and pH 9.5-12. The Km value and turnover number kcat for leucine of PrLeuDH were 2.23 ± 0.12 mM and 35.39 ± 0.05 s-1, respectively, resulting in a catalytic efficiency kcat/Km of 15.87 s-1/mM. Importantly, PrLeuDH remained 92.1 ± 2.67% active in the presence of 4.0 M NaCl. The study provides the first in-depth understanding of LeuDH from marine Pseudoalteromonas rubra, meanwhile the unique properties of high activity at low temperature and high salt tolerance make it a promising biocatalyst for the synthesis of non-protein amino acids and α-ketoacids under special conditions in pharmaceutical industry.


Asunto(s)
Escherichia coli , Pseudoalteromonas , Clonación Molecular , Estabilidad de Enzimas , Escherichia coli/genética , Concentración de Iones de Hidrógeno , Leucina/genética , Leucina-Deshidrogenasa , Pseudoalteromonas/genética , Proteínas Recombinantes/genética , Cloruro de Sodio
16.
Mol Biotechnol ; 64(1): 57-65, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34532832

RESUMEN

Arginine decarboxylase (ADC) catalyzes the decarboxylation of arginine to form agmatine, an important physiological and pharmacological amine, and attracts attention to the enzymatic production of agmatine. In this study, we for the first time overexpressed and characterized the marine Shewanella algae ADC (SaADC) in Escherichia coli. The recombinant SaADC showed the maximum activity at pH 7.5 and 40 °C. The SaADC displayed previously unreported substrate inhibition when the substrate concentration was higher than 50 mM, which was the upper limit of testing condition in other reports. In the range of 1-80 mM L-arginine, the SaADC showed the Km, kcat, Ki, and kcat/Km values of 72.99 ± 6.45 mM, 42.88 ± 2.63 s-1, 20.56 ± 2.18 mM, and 0.59 s/mM, respectively, which were much higher than the Km (14.55 ± 1.45 mM) and kcat (12.62 ± 0.68 s-1) value obtained by assaying at 1-50 mM L-arginine without considering substrate inhibition. Both the kcat values of SaADC with and without substrate inhibition are the highest ones to the best of our knowledge. This provides a reference for the study of substrate inhibition of ADCs.


Asunto(s)
Proteínas Bacterianas/metabolismo , Carboxiliasas/metabolismo , Escherichia coli/genética , Shewanella/enzimología , Agmatina/metabolismo , Arginina/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Carboxiliasas/química , Carboxiliasas/genética , Carboxiliasas/aislamiento & purificación , Codón , Expresión Génica , Concentración de Iones de Hidrógeno , Cinética , Modelos Moleculares , Estabilidad Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Temperatura
17.
Molecules ; 26(23)2021 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-34885702

RESUMEN

Selenocysteine (Sec) is the 21st non-standard proteinogenic amino acid. Due to the particularity of the codon encoding Sec, the selenoprotein synthesis needs to be completed by unique mechanisms in specific biological systems. In this paper, the underlying mechanisms for the biosynthesis and incorporation of Sec into selenoprotein were comprehensively reviewed on five aspects: (i) the specific biosynthesis mechanism of Sec and the role of its internal influencing factors (SelA, SelB, SelC, SelD, SPS2 and PSTK); (ii) the elements (SECIS, PSL, SPUR and RF) on mRNA and their functional mechanisms; (iii) the specificity (either translation termination or translation into Sec) of UGA; (iv) the structure-activity relationship and action mechanism of SelA, SelB, SelC and SelD; and (v) the operating mechanism of two key enzyme systems for inorganic selenium source flow before Sec synthesis. Lastly, the size of the translation initiation interval, other action modes of SECIS and effects of REPS (Repetitive Extragenic Palindromic Sequences) that affect the incorporation efficiency of Sec was also discussed to provide scientific basis for the large-scale industrial fermentation for the production of selenoprotein.


Asunto(s)
Conformación de Ácido Nucleico , Selenio/química , Selenocisteína/genética , Selenoproteínas/genética , ARN Mensajero/química , ARN Mensajero/genética , Selenocisteína/biosíntesis , Selenocisteína/química , Selenoproteínas/biosíntesis , Selenoproteínas/química , Selenoproteínas/ultraestructura , Relación Estructura-Actividad
18.
Medicine (Baltimore) ; 100(28): e26611, 2021 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-34260546

RESUMEN

RATIONALE: Nutcracker and superior mesenteric artery (SMA) syndrome share the same pathogenesis, but the simultaneous occurrence of both diseases is quite rare. A combination of the nutcracker syndrome and IgA nephropathy has previously been reported. Herein, we report what we believe is the first case of coexisting nutcracker and SMA syndrome in a patient with IgA nephropathy. PATIENT CONCERNS: A 15-year-old Chinese boy who was diagnosed with IgA nephropathy at 8 years of age presented with gross hematuria, fatigue, anorexia, nausea, and recurrent abdominal distension for 1 week without any obvious evidence of preceding infection. Laboratory data showed macroscopic hematuria, heavy proteinuria, and relatively normal renal function. Doppler ultrasonography and upper gastrointestinal gastrografin study were performed, respectively. Since his renal function deteriorated after admission, repeated renal biopsy was performed. DIAGNOSES: IgA nephropathy with nutcracker phenomenon and SMA syndrome. INTERVENTION: Immunosuppressive therapy combined with conservative therapy for superior mesenteric artery syndrome. OUTCOMES: One month later, his abdomen symptoms such as anorexia and abdominal distension eased a lot with body weight increase of about 3 kg. After 6 months of follow-up, his body weight increased to 57 kg, serum creatinine decreased to 63 µmol/L, and urine microscopy showed 75.5 RBC/high-power field with 0.3 g urine protein per day. LESSONS: Although the association between vascular compression and IgA nephropathy (IgAN) has not been elucidated yet, combination of nutcracker syndrome and SMA syndrome should be considered in patients with IgAN. The combination may increase the complexity of the disease, and renal biopsy should not be hesitated for differential diagnosis.


Asunto(s)
Glomerulonefritis por IGA/complicaciones , Síndrome de Cascanueces Renal/complicaciones , Síndrome de la Arteria Mesentérica Superior/complicaciones , Adolescente , Humanos , Masculino
19.
J Sci Food Agric ; 101(6): 2472-2482, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33034040

RESUMEN

BACKGROUND: Exoinulinase catalyzes the successive removal of individual fructose moiety from the non-reducing end of the inulin molecule, which is useful for biotechnological applications like producing fructan-based non-grain biomass energy and high-fructose syrup. In this study, an exoinulinase (KmINU) from Kluyveromyces marxianus DSM 5418 was tailored for increased catalytic activity and acidic adaptation for inulin hydrolysis processes by rational site-directed mutagenesis. RESULTS: Three mutations, S124Y, N158S and Q215V distal to the catalytic residues of KmINU were designed and heterologously expressed in Pichia pastoris GS115. Compared to the wild-type, S124Y shifted the pH-activity profile towards acidic pH values and increased the catalytic activity and catalytic efficiency by 59% and 99% to 688.4 ± 17.03 s-1 and 568.93 L mmol-1 s-1 , respectively. N158S improved the catalytic activity under acidic pH conditions, giving a maximum value of 464.06 ± 14.06 s-1 on inulin at pH 4.5. Q215V markedly improved the substrate preference for inulin over sucrose by 5.56-fold, and showed catalytic efficiencies of 208.82 and 6.88 L mmol-1 s-1 towards inulin and sucrose, respectively. Molecular modeling and computational docking indicated that structural reorientation may underlie the increased catalytic activity, acidic adaptation and substrate preference. CONCLUSIONS: The KmINU mutants may serve as industrially promising candidates for inulin hydrolysis. Protein engineering of exoinulinase here provides a successful example of the extent to which mutating non-conserved substrate recognition and binding residues distal to the active site can be used for industrial enzyme improvements. © 2020 Society of Chemical Industry.


Asunto(s)
Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Glicósido Hidrolasas/química , Glicósido Hidrolasas/genética , Kluyveromyces/enzimología , Ácidos/metabolismo , Catálisis , Estabilidad de Enzimas , Proteínas Fúngicas/metabolismo , Glicósido Hidrolasas/metabolismo , Concentración de Iones de Hidrógeno , Inulina/metabolismo , Cinética , Kluyveromyces/química , Kluyveromyces/genética , Mutagénesis Sitio-Dirigida , Ingeniería de Proteínas
20.
Biomed Pharmacother ; 129: 110436, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32768938

RESUMEN

The present study investigates the differences in inflammatory agents alterations, immune function, and leukocyte differential count evaluation in severe pneumonia of SARS-COV-2 patients with Yidu-toxicity blocking lung syndrome after the recommended Chinese medicine prescription of Yidu-toxicity blocking lung decoction. A total of 40 patients with yidu-toxicity blocking lung syndrome, diagnosed as severe pneumonia of SARS-COV-2 following the latest Chinese national recommendations for the diagnosis and treatment of pneumonia caused by SARS-COV-2 (the 5th edition), were recruited. They were randomly divided into the pure western medicine therapy group (PWM) and integrated into Chinese and Western medicine therapy group (ICW). The general strategies were given to both groups according to the national recommendations, and the ICW group was given Yidu-toxicity blocking lung decoction extraorally. A radioimmunoassay method was adopted to detect the content of IL-6, IL-8,IL-2R,TNF-α, procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) in sera. Flow cytometry was used to determine the peripheral blood lymphocyte subsets (the levels of CD3+, CD4+, CD8+, and the ratios of CD4+/CD8+). The white blood cell counts (WBC#), neutrophils count(N#), and lymphocyte counts (L#) were measured using a fully automatic blood rheological instrument. The t-test or Rank Sum Test and Spearman analysis were conducted to evaluate the differences. The results showed that IL-6 (P = 0.013) and TNF-α (P = 0.035) levels in the PWM group were significantly higher than those in the ICW group after treatment. Infection related indicators such as WBC#, N#, L#, hs-CRP showed no differences. The analysis showed that there was no statistical difference in the values of CD4 and CD8 between the two groups. By the end of Day 29, all patients were discharged and the final cure rate for both group were 100 %. Taken together, we conclude that Yidu-toxicity blocking lung decoction could relieve inflammation of SARS-COV-2 patients with yidu-toxicity blocking lung syndrome by eliminating inflammatory agents. CM can serve as a complementary medication to western medicine, which should be highlighted in clinical settings.


Asunto(s)
Infecciones por Coronavirus/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Inflamación/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Betacoronavirus/efectos de los fármacos , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/virología , Medicamentos Herbarios Chinos/administración & dosificación , Femenino , Humanos , Inflamación/virología , Interleucina-6/metabolismo , Recuento de Leucocitos , Recuento de Linfocitos , Subgrupos Linfocitarios , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/virología , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Factor de Necrosis Tumoral alfa/metabolismo , Tratamiento Farmacológico de COVID-19
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