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1.
Philos Trans R Soc Lond B Biol Sci ; 378(1871): 20220029, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36633285

RESUMO

By linking amino acids to their codon assignments, transfer RNAs (tRNAs) are essential for protein synthesis and translation fidelity. Some human tRNA variants cause amino acid mis-incorporation at a codon or set of codons. We recently found that a naturally occurring tRNASer variant decodes phenylalanine codons with serine and inhibits protein synthesis. Here, we hypothesized that human tRNA variants that misread glycine (Gly) codons with alanine (Ala) will also disrupt protein homeostasis. The A3G mutation occurs naturally in tRNAGly variants (tRNAGlyCCC, tRNAGlyGCC) and creates an alanyl-tRNA synthetase (AlaRS) identity element (G3 : U70). Because AlaRS does not recognize the anticodon, the human tRNAAlaAGC G35C (tRNAAlaACC) variant may function similarly to mis-incorporate Ala at Gly codons. The tRNAGly and tRNAAla variants had no effect on protein synthesis in mammalian cells under normal growth conditions; however, tRNAGlyGCC A3G depressed protein synthesis in the context of proteasome inhibition. Mass spectrometry confirmed Ala mistranslation at multiple Gly codons caused by the tRNAGlyGCC A3G and tRNAAlaAGC G35C mutants, and in some cases, we observed multiple mistranslation events in the same peptide. The data reveal mistranslation of Ala at Gly codons and defects in protein homeostasis generated by natural human tRNA variants that are tolerated under normal conditions. This article is part of the theme issue 'Reactivity and mechanism in chemical and synthetic biology'.


Assuntos
Alanina-tRNA Ligase , Biossíntese de Proteínas , Humanos , Alanina/genética , Alanina/química , Alanina/metabolismo , Alanina-tRNA Ligase/química , Alanina-tRNA Ligase/genética , Alanina-tRNA Ligase/metabolismo , Códon/genética , Glicina/genética , Glicina/metabolismo , Proteostase , RNA de Transferência/genética , RNA de Transferência/metabolismo , RNA de Transferência de Alanina/química , RNA de Transferência de Alanina/genética , RNA de Transferência de Alanina/metabolismo , RNA de Transferência de Glicina/metabolismo
2.
Food Microbiol ; 111: 104193, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36681397

RESUMO

Although the impact of nitrogen nutrition on the production of fermentative aromas in oenological fermentation is well known today, one may wonder whether the effects studied are the same when winemaking takes place at high turbidities, specifically for the production of wines intended for cognac distillation. To that effect, a fermentation robot was used to analyze 30 different fermentation conditions at two turbidity levels with several factors tested: (i) initial addition of nitrogen either organic (with a mixture of amino acids - MixAA) or inorganic with di-ammonium phosphate (DAP) at different concentrations, (ii) variation of the ratio of inorganic/organic nitrogen (MixAA and DAP) and (iii) addition of different single amino acids (alanine, arginine, aspartic acid and glutamic acid). A metabolomic analysis was carried out on all resulting wines to have a global vision of the impact of nitrogen on more than sixty aromatic molecules of various families. Then, at the end of the alcoholic fermentation, the wines were micro-distilled. A first interesting observation was that the aroma profiles of both wines and distillates were close, indicating that the concentration factor is rather similar for the different aromas studied. Secondly, the fermentation kinetics and aroma results have shown that the nitrogen concentration effect prevailed over the nature of nitrogen. Although the lipid concentration was in excess, an interaction between the assimilable nitrogen and lipid contents was still observed in wines or in micro-distillates. Alanine is involved in the synthesis of acetaldehyde, isobutanol, isoamyl alcohol and isoamyl acetate. Finally, it was demonstrated that modifying the ratio of assimilable nitrogen in musts is not an interesting technological response to improve the aromatic profile of wines and brandies. Indeed, unbalance the physiological ratio of the must by adding a single source of assimilable nitrogen (organic or inorganic) has been shown to deregulate the synthesis of most of the fermentation aromas produced by the yeast. Wine metabolomic analysis confirmed the results that had been observed in micro-distillates but also in the other aromatic families, especially on terpenes. The contribution of solid particles, but also yeast biosynthesis (via sterol management in must) to wine terpenes is discussed. Indeed, the synthesis of terpenes in this oenological context seems to be favored, especially since the concentration of assimilable nitrogen (in addition to the lipid content) favor their accumulation in the medium. A non-negligible vintage effect on the terpene profile was also demonstrated with variations in their distribution depending on the years. Thus, the present study focuses on the metabolism of wine yeasts under different environmental conditions (nitrogen and lipid content) and on the impact of distillation on the fate of flavor compounds. The results highlight once again the complexity of metabolic fluxes and of the impact of nitrogen source (nature and amount) and of lipids. Furthermore, this study demonstrates that beyond the varietal origin of terpenes, the part resulting from the de novo synthesis by the yeast during the fermentation cannot be neglected in the context of cognac winemaking with high levels of turbidity.


Assuntos
Vitis , Vinho , Humanos , Vinho/análise , Vitis/química , Saccharomyces cerevisiae/metabolismo , Nitrogênio/metabolismo , Odorantes/análise , Aminoácidos/metabolismo , Fermentação , Lipídeos , Terpenos/análise , Terpenos/metabolismo , Alanina/análise , Alanina/metabolismo
3.
Artigo em Inglês | MEDLINE | ID: mdl-36673839

RESUMO

BACKGROUND: This study evaluated the clinical outcomes of patients with severe COVID-19 pneumonia treated with remdesivir plus standard corticosteroid treatment (SCT) or with remdesivir plus high-dose corticosteroid pulse therapy (HDCPT). METHODS: One hundred and two patients with severe COVID-19 pneumonia and respiratory failure were included. The patients were divided into two cohorts. The first comprised patients who received remdesivir and SCT, consisting of 6 mg dexamethasone daily for up to 10 days or until hospital discharge. The second included patients who received remdesivir and HDCPT, composed of 250 mg iv of methylprednisolone for three days, followed by a slow reduction in the dose of steroids. The severity of hypoxemia was assessed using the SaO2/FiO2 peripheral oxygen saturation index. RESULTS: 55 received remdesivir plus HDCPT, and 47 received remdesivir plus SCT. Mortality at 30 days was significantly lower among patients who received remdesivir plus HDCPT (4/55) than among those who did not (15/47). In patients who received remdesivir plus HDCPT, 7.3% required invasive mechanical ventilation and admission to the ICU and 36.4% non-invasive ventilation versus 29.8% and 61.7%, respectively, among those treated with remdesivir plus SCT. Remdesivir plus HDCPT induced a significantly faster improvement in the SaO2/FiO2 index. CONCLUSION: Early combination treatment with remdesivir plus HDCPT reduced in-hospital mortality and the need for admission to the ICU. Furthermore, it improved the SaO2/FiO2 index faster in patients with severe COVID-19 pneumonia.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Metilprednisolona/uso terapêutico , Alanina/uso terapêutico , Corticosteroides , Oxigênio
4.
Bioorg Med Chem Lett ; 80: 129122, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36592870

RESUMO

A series of novel trienomycin A (TA)-mimetic compounds (5a-p) have been designed, synthesized, and evaluated for their in vitro anti-neuroinflammatory and neuroprotective activities. Among them, compounds 5h, 5n, and 5o exhibits relatively strong NO inhibitory activity in LPS-activated BV-2 cells with the EC50 values of 12.4, 17.3, and 8.9 µM, respectively. Moreover, 5h showed evidently neuroprotective effect against H2O2-induced PC-12 cells without cytotoxicity at 20 µM. Overall, these compounds can provide a better understanding of the structure-activity relationship of TA and furnish research ideas for anti-neuroinflammatory and neuroprotective agents.


Assuntos
Peróxido de Hidrogênio , Fármacos Neuroprotetores , Ratos , Animais , Peróxido de Hidrogênio/farmacologia , Relação Estrutura-Atividade , Células PC12 , Alanina , Fármacos Neuroprotetores/farmacologia
5.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674540

RESUMO

This study addresses a joint nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy approach to provide a platform for dynamic assessment of kidney viability and metabolism. On porcine kidney models, ROS production, oxidative damage kinetics, and metabolic changes occurring both during the period between organ retrieval and implantation and after kidney graft were examined. The 1H-NMR metabolic profile-valine, alanine, acetate, trimetylamine-N-oxide, glutathione, lactate, and the EPR oxidative stress-resulting from ischemia/reperfusion injury after preservation (8 h) by static cold storage (SCS) and ex vivo machine perfusion (HMP) methods were monitored. The functional recovery after transplantation (14 days) was evaluated by serum creatinine (SCr), oxidative stress (ROS), and damage (thiobarbituric-acid-reactive substances and protein carbonyl enzymatic) assessments. At 8 h of preservation storage, a significantly (p < 0.0001) higher ROS production was measured in the SCS vs. HMP group. Significantly higher concentration data (p < 0.05-0.0001) in HMP vs. SCS for all the monitored metabolites were found as well. The HMP group showed a better function recovery. The comparison of the areas under the SCr curves (AUC) returned a significantly smaller (-12.5 %) AUC in the HMP vs. SCS. EPR-ROS concentration (µmol·g-1) from bioptic kidney tissue samples were significantly lower in HMP vs. SCS. The same result was found for the NMR monitored metabolites: lactate: -59.76%, alanine: -43.17%; valine: -58.56%; and TMAO: -77.96%. No changes were observed in either group under light microscopy. In conclusion, a better and more rapid normalization of oxidative stress and functional recovery after transplantation were observed by HMP utilization.


Assuntos
Transplante de Rim , Animais , Suínos , Transplante de Rim/efeitos adversos , Transplante de Rim/métodos , Preservação de Órgãos/métodos , Espécies Reativas de Oxigênio/metabolismo , Perfusão/métodos , Rim/metabolismo , Estresse Oxidativo , Lactatos/metabolismo , Metaboloma , Alanina/metabolismo
6.
Molecules ; 28(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36677619

RESUMO

Thirty novel diamide compounds combining pyrazolyl and polyfluoro-substituted phenyl groups into alanine or 2-aminobutyric acid skeletons were designed and synthesized with pyflubumide as the lead compound to develop potent and environmentally friendly pesticides. The preliminary bioassay results indicated that the new compounds containing the para-hexa/heptafluoroisopropylphenyl moiety exhibit fungicidal, insecticidal, and acaricidal activities. This is the first time that the para-hexa/heptafluoroisopropylphenyl group is a key fragment of the fungicidal activity of new N-phenyl amide compounds. Most of the target compounds exhibited moderate to good insecticidal activity against Aphis craccivora at a concentration of 400 µg/mL, and some showed moderate activity at a concentration of 200 µg/mL; in particular, compounds I-4, II-a-10, and III-26 displayed higher than 78% lethal rates at 200 µg/mL. Compound II-a-14 exhibited a 61.1% inhibition at 200 µg/mL for Tetranychus cinnabarinus. In addition, some of the target compounds exhibited good insecticidal activities against Plutella xylostella at a concentration of 200 µg/mL; the mortalities of compounds I-1, and II-a-15 were 76.7% and 70.0%, respectively. Preliminary analysis of the structure-activity relationship (SAR) indicated that the insecticidal and acaricidal activities varied significantly depending on the type of substituent and substitution pattern. The fungicidal activity results showed that compounds I-1, II-a-10, II-a-17, and III-26 exhibited good antifungal effects. Enzymatic activity experiments and in vivo efficacy of compound II-a-10 were conducted and discussed.


Assuntos
Acaricidas , Fungicidas Industriais , Inseticidas , Mariposas , Animais , Inseticidas/farmacologia , Diamida/farmacologia , Alanina/farmacologia , Desenho de Fármacos , Relação Estrutura-Atividade , Fungicidas Industriais/farmacologia , Estrutura Molecular
7.
Arch Microbiol ; 205(1): 48, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36595098

RESUMO

Tsukamurella tyrosinosolvens strain P9 is a rare actinomycete with plant growth-promoting properties and can improve the growth of peanut. We analyzed the differentially expressed genes (DEGs) of P9 under the influence of peanut root exudates from RNA-sequencing data and analyzed the effects of root exudates and their organic acid and amino acid components on the growth and growth-promoting effects of this strain to explore the molecular mechanism of the P9 response. The results showed that peanut root exudates promoted the growth and growth-promoting activity of P9. Transcriptome analysis revealed 126 DEGs in P9, comprising 81 up-regulated and 45 down-regulated genes. The DEGs were significantly enriched in 17 KEGG metabolic pathways, including arginine biosynthesis, butyric acid metabolism, fatty acid degradation, and tryptophan metabolism. Peanut root exudates induced up-regulation of nutrient transport, carbohydrate metabolism and energy production, siderophore and IAA biosynthesis, adhesion, and biofilm formation, and down-regulation of arginine biosynthesis and the urea cycle in P9. Organic acids and amino acids are the major components of peanut root exudates. Glycine, proline, and alanine promoted the growth and IAA secretion of P9. Proline, alanine (40 mM), and oxalic acid significantly enhanced siderophore biosynthesis, whereas citric acid, oxalic acid, and malic acid significantly promoted biofilm formation of P9. This study clarifies the response of T. tyrosinosolvens P9 to peanut root exudates at the molecular level, examining the molecular basis of the relationship between P9 and peanut, and provides a theoretical foundation for improved exertion of the growth-promoting properties of P9.


Assuntos
Arachis , Sideróforos , Arachis/metabolismo , Sideróforos/metabolismo , Aminoácidos/metabolismo , Alanina , Exsudatos e Transudatos , Prolina/metabolismo , Arginina/metabolismo , Raízes de Plantas/metabolismo
8.
Medicine (Baltimore) ; 102(1): e32621, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36607856

RESUMO

BACKGROUND: Galectins are a family of endogenous mammalian lectins involved in pathogen recognition, killing, and facilitating the entry of microbial pathogens and parasites into the host. They are the intermediators that decipher glycan-containing information about the host immune cells and microbial structures to modulate signaling events that cause cellular proliferation, chemotaxis, cytokine secretion, and cell-to-cell communication. They have subgroups that take place in different roles in the immune system. The effect of galectin-8 on multiple sclerosis disease (MS) has been studied in the literature, but the results seemed unclear. In this study, we aimed to determine anti-galectin-8 (anti-Gal-8) levels in MS and their potential use as biomarkers. METHODS: In this experimental study, 45 MS patients diagnosed according to McDonald criteria were included in the patient group. The healthy control group contained 45 people without MS diagnosis and any risk factors. Demographic data, height, weight, body mass index, blood glucose, thyroid-stimulating hormone, alanine transaminase, aspartate transaminase, creatinine, low-density lipoprotein, anti-Gal-8 levels, the prevalence of hypertension, diabetes mellitus and coronary artery disease were recorded. In addition, the expanded disability status scale and disease duration were evaluated in the patient group. Data were presented as mean ±â€…standard deviations. RESULTS: The mean blood anti-galectin-8 value of the patient group was 4.84 ±â€…4.53 ng/mL, while it was 4.67 ±â€…3.40 ng/mL in the control group, and the difference in these values was found statistically insignificant (P > .05). Moreover, body mass index, glucose, alanine transaminase, aspartate transaminase, thyroid-stimulating hormone, and low-density lipoprotein levels were also statistically insignificant (P > .05). CONCLUSION: This study examined anti-Gal-8 levels in MS patients. The relationship between MS and galectin-8 and anti-Gal-8 levels in patients needs further clarification. As a result, the study's results could help elucidate the pathogenesis of MS and give more evidence for diagnosis.


Assuntos
Galectina 3 , Esclerose Múltipla , Humanos , Alanina , Biomarcadores , Galectina 3/química , Mamíferos , Transaminases
9.
Protein Eng Des Sel ; 362023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36611015

RESUMO

Human transthyretin (TTR) is a homo-tetrameric plasma protein associated with a high percentage of ß-sheet forming amyloid fibrils. It accumulates in tissues or extracellular matrices to cause amyloid diseases. Free energy simulations with thermodynamic integration based on all-atom molecular dynamics simulations have been carried out to analyze the effects of the His88 â†’ Ala and Ser mutations on the stability of human TTR. The calculated free energy change differences (ΔΔG) caused by the His88 â†’ Ala and His88 â†’ Ser mutations are -1.84 ± 0.86 and 7.56 ± 0.55 kcal/mol, respectively, which are in excellent agreement with prior reported experimental values. The simulation results show that the H88A mutant is more stable than the wild type, whereas the H88S mutant is less stable than the wild type. The free energy component analysis shows that the contribution to the free energy change difference (ΔΔG) for the His88 â†’ Ala and His88 â†’ Ser mutations mainly arise from electrostatic and van der Waals interactions, respectively. The electrostatic term stabilizes the H88A mutant more than the wild type, but the van der Waals interaction destabilizes the H88S mutant relative to the wild type. Individual residue contributions to the free energy change show neighboring residues exert stabilizing and destabilizing influence on the mutants. The implications of the simulation results for understanding the stabilizing and destabilizing effect and its contribution to protein stability are discussed.


Assuntos
Alanina , Pré-Albumina , Humanos , Pré-Albumina/genética , Pré-Albumina/química , Pré-Albumina/metabolismo , Alanina/genética , Serina/genética , Simulação de Dinâmica Molecular , Estabilidade Proteica , Termodinâmica
10.
Pharmacol Res Perspect ; 11(1): e01053, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36639940

RESUMO

Angiotensin II analogue and ß-arrestin biased agonist TRV027 (Sarcosine1 , d-Alanine8 -Angiotensin (Ang) II; SD Ang II), developed by Trevena, Inc. in the early 2010s, brought hopes of a novel treatment for cardiovascular diseases, due to its ability to simultaneously cause signaling through the ß-arrestin signaling pathway, while antagonizing the pathophysiological effects of Ang II mediated by the AT1 receptor G protein signaling cascades. However, a phase II clinical trial of this agent revealed no significant benefit compared to placebo treatment. Using 125 I-Sarcosine1 , Isoleucine8 -Ang II (125 I-SI Ang II) radioligand receptor competition binding assays, we assessed the relative affinity of TRV027 compared to SI Ang II for liver AT1 receptors. We also compared radioiodinated TRV027 (125 I-SD Ang II) binding affinity for liver AT1 receptors with 125 I-SI Ang II. We found that despite its anticipated gain in metabolic stability, TRV027 and 125 I-SD Ang II had reduced affinity for the AT1 receptor compared with SI Ang II and 125 I-SI Ang II. Additionally, male-female comparisons showed that females have a higher AT1 receptor density, potentially attributed to tissue-dependent estrogen and progesterone effects. Peptide drugs have become more popular over the years due to their increased bioavailability, fast onset of action, high specificity, and low toxicity. Even though Trevena®'s biased agonist peptide TRV027 offered greater stability and potency compared to earlier AT1 R biased agonists, it failed its phase II clinical trial in 2016. Further refinements to AT1 R biased agonist peptides to improve affinity, as seen with SI Ang II, with better stability and bioavailability, has the potential to achieve the anticipated biased agonism.


Assuntos
Angiotensina II , Fígado , Receptor Tipo 1 de Angiotensina , Sarcosina , Animais , Feminino , Masculino , Ratos , Alanina/metabolismo , Angiotensina II/farmacologia , beta-Arrestinas/metabolismo , Isoleucina/metabolismo , Fígado/metabolismo , Sarcosina/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo
11.
Planta ; 257(2): 41, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36680621

RESUMO

MAIN CONCLUSION: Severe N stress allows an accumulation of C-based compounds but impedes that of N-based compounds required to lower the susceptibility of tomato stem to Botrytis cinerea. Botrytis cinerea, a necrotrophic filamentous fungus, forms potentially lethal lesions on the stems of infected plants. Contrasted levels of susceptibility to B. cinerea were obtained in a tomato cultivar grown on a range of nitrate concentration: low N supply resulted in high susceptibility while high N supply conferred a strong resistance. Metabolic deviations and physiological traits resulting from both infection and nitrogen limitation were investigated in the symptomless stem tissue surrounding the necrotic lesion. Prior to infection, nitrogen-deficient plants showed reduced levels of nitrogen-based compounds such as amino acids, proteins, and glutathione and elevated levels of carbon-based and defence compounds such as α-tomatine and chlorogenic acid. After B. cinerea inoculation, all plants displayed a few common responses, mainly alanine accumulation and galactinol depletion. The metabolome of resistant plants grown under high N supply showed no significant change after inoculation. On the contrary, the metabolome of susceptible plants grown under low N supply showed massive metabolic adjustments, including changes in central metabolism around glutamate and respiratory pathways, suggesting active resource mobilization and production of energy and reducing power. Redox and defence metabolisms were also stimulated by the infection in plants grown under low N supply; glutathione and chlorogenic acid accumulated, as well as metabolites with more controversial defensive roles, such as polyamines, GABA, branched-chain amino acids and phytosterols. Taken together, the results showed that nitrogen deficiency, although leading to an increase in secondary metabolites even before the pathogen attack, must have compromised the constitutive levels of defence proteins and delayed or attenuated the induced responses. The involvement of galactinol, alanine, cycloartenol and citramalate in the tomato stem response to B. cinerea is reported here for the first time.


Assuntos
Nitrogênio/metabolismo , Ácido Clorogênico , Botrytis/metabolismo , Alanina/metabolismo , Glutationa , Doenças das Plantas/microbiologia , Regulação da Expressão Gênica de Plantas
12.
Commun Biol ; 6(1): 118, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36709236

RESUMO

Although Clostridium novyi-NT is an anti-cancer bacterial therapeutic which germinates within hypoxic tumors to kill cancer cells, the actual germination triggers for C. novyi-NT are still unknown. In this study, we screen candidate germinants using combinatorial experimental designs and discover by serendipity that D-valine is a potent germinant, inducing 50% spore germination at 4.2 mM concentration. Further investigation revealed that five D-valine analogs are also germinants and four of these analogs are enantiomeric pairs. This stereoflexible effect of L- and D-amino acids shows that spore germination is a complex process where enantiomeric interactions can be confounders. This study also identifies L-cysteine as a germinant, and hypoxanthine and inosine as co-germinants. Several other amino acids promote (L-valine, L-histidine, L-threonine and L-alanine) or inhibit (L-arginine, L-glycine, L-lysine, L-tryptophan) germination in an interaction-dependent manner. D-alanine inhibits all germination, even in complex growth media. This work lays the foundation for improving the germination efficacy of C. novyi-NT spores in tumors.


Assuntos
Esporos Bacterianos , Valina , Valina/metabolismo , Valina/farmacologia , Esporos Bacterianos/metabolismo , Aminoácidos/metabolismo , Alanina , Esporos/metabolismo
13.
Biochim Biophys Acta Mol Basis Dis ; 1869(1): 166584, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36280155

RESUMO

Since the outbreak of coronavirus disease 2019 (COVID-19), biomarkers for evaluating severity, as well as supportive care to improve clinical course, remain insufficient. We explored the potential of d-amino acids, rare enantiomers of amino acids, as biomarkers for assessing disease severity and as protective nutrients against severe viral infections. In mice infected with influenza A virus (IAV) and in patients with severe COVID-19 requiring artificial ventilation or extracorporeal membrane oxygenation, blood levels of d-amino acids, including d-alanine, were reduced significantly compared with those of uninfected mice or healthy controls. In mice models of IAV infection or COVID-19, supplementation with d-alanine alleviated severity of clinical course, and mice with sustained blood levels of d-alanine showed favorable prognoses. In severe viral infections, blood levels of d-amino acids, including d-alanine, decrease, and supplementation with d-alanine improves prognosis. d-Alanine has great potentials as a biomarker and a therapeutic option for severe viral infections.


Assuntos
Doenças Transmissíveis , Influenza Humana , Camundongos , Animais , Humanos , Influenza Humana/tratamento farmacológico , Alanina/uso terapêutico , SARS-CoV-2 , Biomarcadores
14.
Int J Infect Dis ; 127: 124-128, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36521589

RESUMO

OBJECTIVES: Access and appropriateness of therapeutics for COVID-19 vary because of access or regulatory barriers, the severity of the disease, and for some therapies, the stage of the pandemic and circulating variants. Remdesivir has shown benefits in clinical recovery and is the treatment of choice for selected patients, both hospitalized and nonhospitalized, in main international guidelines. The use of remdesivir in alternatives to conventional hospitalization such as hospital at home (HaH) units remains incompletely explored. In this study, we aim to describe the real-life experience of outpatient remdesivir infusion for COVID-19 in a HaH unit. METHODS: We selected all the consecutive patients receiving remdesivir from a prospective cohort of 507 COVID-19 patients admitted at a HaH unit. Admission criteria included COVID-19 with a fraction of inspired oxygen requirement under 0.35 and respiratory rate under 22 rpm. Patients were daily assessed in person by a nurse and a physician. RESULTS: A total of 236 patients admitted at the HaH unit received remdesivir, 172 of whom were treated at home. Only 2% presented any adverse event related to the infusion, all of them mild. HaH saved 1416 day-beds, with only 5% of the patients requiring transfer back to the hospital. CONCLUSION: Remdesivir infusion in HaH units seems to be a safe and efficient alternative to conventional hospitalization for treating patients with nonsevere COVID-19.


Assuntos
COVID-19 , Humanos , Estudos Prospectivos , Alanina/uso terapêutico , Hospitais
15.
Biochim Biophys Acta Proteins Proteom ; 1871(2): 140886, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36496204

RESUMO

Pyridoxal-5'-phosphate-(PLP-) dependent D-amino acid transaminases (DAATs) catalyze stereoselective reversible transfer of the amino group between D-amino acids and keto acids. In vivo DAATs are commonly known to synthesize D-glutamate for cell wall peptidoglycans. Today DAATs meet increasing attention for application in the synthesis of D-amino acids, whereas little is known about the mechanism of substrate recognition and catalytic steps of the D-amino acids conversion by DAATs. In this work, the pre-steady-state kinetics of the half-reactions of DAAT from Haliscomenobacter hydrossis with D-glutamate, D-alanine, D-leucine, and D-phenylalanine was examined at two wavelengths, 416 and 330 nm, using a stopped-flow technique. Monophasic kinetics was observed with specific substrates D-glutamate and D-alanine, whereas half-reactions with D-leucine and D-phenylalanine exhibited biphasic kinetics. All half-reactions proceeded until the complete conversion of PLP due to the release of the pyridoxamine-5'-phosphate form of cofactor from the holoenzyme . Comparison of kinetic parameters of half-reactions and the overall transamination reactions for D-leucine, D-phenylalanine revealed the increase in the rates of deamination of these substrates in the overall reaction with α-ketoglutarate. In the overall transamination reaction, the catalytic turnover rates for D-leucine and D-phenylalanine increased by 260 and 60 times, correspondingly, comparing with the slowest step rate constants in the half-reactions. We suggested the activating effect by a specific substrate α-ketoglutarate in the overall transamination reaction. The study of half-reactions helped to quantify the specificity of DAAT from H. hydrossis for D-amino acids with different properties. The results obtained are the first detailed analysis of half-reactions catalyzed by DAAT.


Assuntos
Aminoácidos , Transaminases , Transaminases/química , Ácido Glutâmico , Leucina , Ácidos Cetoglutáricos , Alanina , Fosfato de Piridoxal/química , Fenilalanina , Catálise , Fosfatos
16.
Biomacromolecules ; 24(1): 344-357, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36563170

RESUMO

Although the supramolecular helical structures of biomacromolecules have been studied, the examples of supramolecular systems that are assembled using coils to form helical polymer chains are still limited. Inspired by enhanced helical chirality at the supramolecular level in metal coordination-induced protein folding, a series of alanine-based coil copolymers (poly-(l-co-d)-ala-NH2) carrying (l)- and (d)-alanine pendants were synthesized as a fresh research model to study the cooperative processes between homochirality property and metal coordination. The complexes of poly-(l-co-d)-ala-NH2 and metal ions underwent a coil-to-helix transition and exhibited remarkable nonlinear effects based on the enantiomeric excess of the monomer unit in the copolymers, affording enhanced helical chirality compared to poly-(l-co-d)-ala-NH2. More importantly, the synergistic effect of amplification of asymmetry and metal coordination triggered the formation of a helical molecular orbital on the polymer backbone via the coordination with the d orbital of copper ions. Thus, the helical chirality enhancement degree of poly-(l-co-d)-ala-NH2/Cu2+ complexes (31.4) is approximately 3 times higher than that of poly-(l-co-d)-ala-NH2/Ag+ complexes (9.8). This study not only provides important mechanistic insights into the enhancement of helical chirality for self-assembly but also establishes a new strategy for studying the homochiral amplification of asymmetry in biological supramolecular systems.


Assuntos
Alanina , Metais , Metais/química , Substâncias Macromoleculares , Alanina/química , Polímeros/química , Íons , Dobramento de Proteína
17.
Proc Natl Acad Sci U S A ; 119(49): e2214906119, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36459640

RESUMO

The primary goal of protein science is to understand how proteins function, which requires understanding the functional dynamics responsible for transitions between different functional structures of a protein. A central concept is the exact reaction coordinates that can determine the value of committor for any protein configuration, which provide the optimal description of functional dynamics. Despite intensive efforts, identifying the exact reaction coordinates (RCs) in complex molecules remains a formidable challenge. Using the recently developed generalized work functional, we report the discovery of the exact RCs for an important functional process-the flap opening of HIV-1 protease. Our results show that this process has six RCs, each one is a linear combination of ~240 backbone dihedrals, providing the precise definition of collectivity and cooperativity in the functional dynamics of a protein. Applying bias potentials along each RC can accelerate flap opening by [Formula: see text] to [Formula: see text] folds. The success in identifying the RCs of a protein with 198 residues represents a significant progress beyond that of the alanine dipeptide, currently the only other complex molecule for which the exact RCs for its conformational changes are known. Our results suggest that the generalized work functional (GWF) might be the fundamental operator of mechanics that controls protein dynamics.


Assuntos
Alanina , Protease de HIV , Dipeptídeos , Coluna Vertebral
18.
Proc Natl Acad Sci U S A ; 119(49): e2215855119, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36459643

RESUMO

Most diazotrophs fix nitrogen only under nitrogen-limiting conditions, for example, in the presence of relatively low concentrations of NH4+ (0 to 2 mM). However, Paenibacillus sabinae T27 exhibits an unusual pattern of nitrogen regulation of nitrogen fixation, since although nitrogenase activities are high under nitrogen-limiting conditions (0 to 3 mM NH4+) and are repressed under conditions of nitrogen sufficiency (4 to 30 mM NH4+), nitrogenase activity is reestablished when very high levels of NH4+ (30 to 300 mM) are present in the medium. To further understand this pattern of nitrogen fixation regulation, we carried out transcriptome analyses of P. sabinae T27 in response to increasing ammonium concentrations. As anticipated, the nif genes were highly expressed, either in the absence of fixed nitrogen or in the presence of a high concentration of NH4+ (100 mM), but were subject to negative feedback regulation at an intermediate concentration of NH4+ (10 mM). Among the differentially expressed genes, ald1, encoding alanine dehydrogenase (ADH1), was highly expressed in the presence of a high level of NH4+ (100 mM). Mutation and complementation experiments revealed that ald1 is required for nitrogen fixation at high ammonium concentrations. We demonstrate that alanine, synthesized by ADH1 from pyruvate and NH4+, inhibits GS activity, leading to a low intracellular glutamine concentration that prevents feedback inhibition of GS and mimics nitrogen limitation, enabling activation of nif transcription by the nitrogen-responsive regulator GlnR in the presence of high levels of extracellular ammonium.


Assuntos
Alanina Desidrogenase , Compostos de Amônio , Fixação de Nitrogênio/genética , Alanina/genética , Nitrogênio , Ácido Pirúvico , Nitrogenase/genética
19.
PLoS One ; 17(12): e0278963, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36584166

RESUMO

Remdesivir (RDV) is the only antiviral drug approved for COVID-19 therapy by the FDA. Another drug LAGEVRIO™ (molnupiravir) though has not been approved yet by FDA but has been authorized on December 23, 2021, for emergency use to treat adults with mild-to moderate COVID-19 symptoms and for whom alternative COVID-19 treatment options are not clinically appropriate. The fact is that the efficacy of RDV is, however, limited in vivo though it is highly promising in vitro against SARS-CoV-2 virus. In this paper we are focusing on the action mechanism of RDV and how it can be improved in vivo. The stability of RDV alone and on encapsulation with our platform technology based polymer NV-387 (NV-CoV-2), were compared in presence of plasma in vitro and in vivo. Furthermore, a non-clinical pharmacology study of NV-CoV-2 (Polymer) and NV CoV-2 (Polymer encapsulated Remdesivir) in both NL-63 infected and uninfected rats was done. In addition, the antiviral activity of NV-CoV-2 and NV-CoV-2-R was compared with RDV in a cell culture study. The results are (i) NV-CoV-2 polymer encapsulation protects RDV from plasma-mediated catabolism in both in vitro and in vivo, studies; (ii) Body weight measurements of the normal (uninfected) rats after administration of the test materials (NV-CoV-2 and NV-CoV-2-R) showed no toxic effects. (iii) Body weight measurements and survival rates of the NL-63 infected rats were similar to the uninfected rats after treatment with NV-CoV-2 and NV-CoV-2-R. Overall, the efficacy as an antiviral regimens were found in this order as below; NV-CoV-2-R > NV-CoV-2 > RDV. Our platform technology based NV-387-encapsulated-RDV (NV-CoV-2-R) drug has a dual effect against different variants of the coronaviruses. First, NV-CoV-2 is an antiviral regimen. Secondly, RDV is protected from plasma-mediated degradation in transit. All together, NV-CoV-2-R is the safest and efficient regimen against COVID-19.


Assuntos
COVID-19 , Humanos , Animais , Ratos , SARS-CoV-2 , Antivirais/farmacologia , Antivirais/uso terapêutico , Biomimética , Monofosfato de Adenosina/farmacologia , Monofosfato de Adenosina/uso terapêutico , Alanina/farmacologia , Alanina/uso terapêutico , Peso Corporal
20.
Sci Rep ; 12(1): 21773, 2022 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-36526888

RESUMO

The number of patients on hemodialysis is increasing globally; diabetes mellitus (DM) complications is the major cause of hemodialysis in patients with chronic kidney disease (CKD). The D-amino acid (AA) profile is altered in patients with CKD; however, it has not been studied in patients with CKD and DM. Furthermore, bacteria responsible for altering the D-AA profile are not well understood. Therefore, we examined the D-AA profiles and associated bacteria in patients with CKD, with and without DM. We enrolled 12 healthy controls and 54 patients with CKD, with and without DM, and determined their salivary, stool, plasma, and urine chiral AA levels using two-dimensional high-performance liquid chromatography. We performed 16S rRNA gene sequencing analysis of the oral and gut microbiota to determine the association between the abundance of bacterial species and D-AA levels. Plasma D-alanine and D-serine levels were higher in patients with CKD than in healthy adults (p < 0.01), and plasma D-alanine levels were higher in patients with CKD and DM than in those without DM. The abundance of salivary Streptococcus, which produced D-alanine, increased in patients with CKD and DM and was positively correlated with plasma D-alanine levels. Patients with CKD and DM had unique oral microbiota and D-alanine profiles. Plasma D-alanine is a potential biomarker for patients with CKD and DM.


Assuntos
Diabetes Mellitus , Insuficiência Renal Crônica , Adulto , Humanos , RNA Ribossômico 16S/genética , Alanina , Insuficiência Renal Crônica/complicações , Bactérias/genética , Streptococcus/genética
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