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1.
Open Biol ; 14(6): 230418, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38835240

RESUMO

Mutations in the protein superoxide dismutase-1 (SOD1) promote its misfolding and aggregation, ultimately causing familial forms of the debilitating neurodegenerative disease amyotrophic lateral sclerosis (ALS). Currently, over 220 (mostly missense) ALS-causing mutations in the SOD1 protein have been identified, indicating that common structural features are responsible for aggregation and toxicity. Using in silico tools, we predicted amyloidogenic regions in the ALS-associated SOD1-G85R mutant, finding seven regions throughout the structure. Introduction of proline residues into ß-strands II (I18P) or III (I35P) reduced the aggregation propensity and toxicity of SOD1-G85R in cells, significantly more so than proline mutations in other amyloidogenic regions. The I18P and I35P mutations also reduced the capability of SOD1-G85R to template onto previously formed non-proline mutant SOD1 aggregates as measured by fluorescence recovery after photobleaching. Finally, we found that, while the I18P and I35P mutants are less structurally stable than SOD1-G85R, the proline mutants are less aggregation-prone during proteasome inhibition, and less toxic to cells overall. Our research highlights the importance of a previously underappreciated SOD1 amyloidogenic region in ß-strand II (15QGIINF20) to the aggregation and toxicity of SOD1 in ALS mutants, and suggests that ß-strands II and III may be good targets for the development of SOD1-associated ALS therapies.


Assuntos
Esclerose Lateral Amiotrófica , Agregados Proteicos , Superóxido Dismutase-1 , Superóxido Dismutase-1/metabolismo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/química , Humanos , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Mutação , Conformação Proteica em Folha beta , Modelos Moleculares , Prolina/metabolismo , Amiloide/metabolismo , Amiloide/química , Dobramento de Proteína
2.
Nat Commun ; 15(1): 4748, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834585

RESUMO

Non-self recognition is a fundamental aspect of life, serving as a crucial mechanism for mitigating proliferation of molecular parasites within fungal populations. However, studies investigating the potential interference of plants with fungal non-self recognition mechanisms are limited. Here, we demonstrate a pronounced increase in the efficiency of horizontal mycovirus transmission between vegetatively incompatible Sclerotinia sclerotiorum strains in planta as compared to in vitro. This increased efficiency is associated with elevated proline concentration in plants following S. sclerotiorum infection. This surge in proline levels attenuates the non-self recognition reaction among fungi by inhibition of cell death, thereby facilitating mycovirus transmission. Furthermore, our field experiments reveal that the combined deployment of hypovirulent S. sclerotiorum strains harboring hypovirulence-associated mycoviruses (HAVs) together with exogenous proline confers substantial protection to oilseed rape plants against virulent S. sclerotiorum. This unprecedented discovery illuminates a novel pathway by which plants can counteract S. sclerotiorum infection, leveraging the weakening of fungal non-self recognition and promotion of HAVs spread. These promising insights provide an avenue to explore for developing innovative biological control strategies aimed at mitigating fungal diseases in plants by enhancing the efficacy of horizontal HAV transmission.


Assuntos
Ascomicetos , Micovírus , Doenças das Plantas , Prolina , Micovírus/fisiologia , Micovírus/genética , Prolina/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Ascomicetos/virologia , Ascomicetos/fisiologia , Brassica napus/microbiologia , Brassica napus/virologia , Virulência , Interações Hospedeiro-Patógeno
3.
Org Lett ; 26(23): 5021-5026, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38842216

RESUMO

We describe a simple and robust oxidation strategy for preparing N-terminal thiazolidine-containing peptide thioesters from peptide hydrazides. We find for the first time that l-thioproline can be used as a protective agent to prevent the nitrosation of N-terminal thiazolidine during peptide hydrazide oxidation. The thioproline-based oxidation strategy has been successfully applied to the chemical synthesis of CC chemokine ligand-2 (69aa) and omniligase-C (113aa), thereby demonstrating its utility in hydrazide-based native chemical ligation.


Assuntos
Oxirredução , Peptídeos , Tiazolidinas , Tiazolidinas/química , Tiazolidinas/síntese química , Estrutura Molecular , Peptídeos/química , Peptídeos/síntese química , Hidrazinas/química , Prolina/química , Ésteres/química , Compostos de Sulfidrila/química
4.
PLoS One ; 19(6): e0298254, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38843201

RESUMO

BACKGROUND: In randomized controlled trials, Nirmatrelvir/ritonavir (NMV/r) and Molnupiravir (MPV) reduced the risk of severe/fatal COVID-19 disease. Real-world data are limited, particularly studies directly comparing the two agents. METHODS: Using the VA National COVID-19 database, we identified previously uninfected, non-hospitalized individuals with COVID-19 with ≥1 risk factor for disease progression who were prescribed either NMV/r or MPV within 3 days of a positive test. We used inverse probability of treatment weights (IPTW) to account for providers' preferences for a specific treatment. Absolute risk difference (ARD) with 95% confidence intervals were determined for those treated with NMV/r vs. MPV. The primary outcome was hospitalization or death within 30 days of treatment prescription using the IPTW approach. Analyses were repeated using propensity-score matched groups. RESULTS: Between January 1 and November 30, 2022, 9,180 individuals were eligible for inclusion (6,592 prescribed NMV/r; 2,454 prescribed MPV). The ARD for hospitalization/death for NMV/r vs MPV was -0.25 (95% CI -0.79 to 0.28). There was no statistically significant difference in ARD among strata by age, race, comorbidities, or symptoms at baseline. Kaplan-Meier curves did not demonstrate a difference between the two groups (p-value = 0.6). Analysis of the propensity-score matched cohort yielded similar results (ARD for NMV/r vs. MPV -0.9, 95% CI -2.02 to 0.23). Additional analyses showed no difference for development of severe/critical/fatal disease by treatment group. CONCLUSION: We found no significant difference in short term risk of hospitalization or death among at-risk individuals with COVID-19 treated with either NMV/r or MPV.


Assuntos
Antivirais , Tratamento Farmacológico da COVID-19 , COVID-19 , Citidina , Progressão da Doença , Hospitalização , Hidroxilaminas , Leucina , Ritonavir , SARS-CoV-2 , Humanos , Masculino , Feminino , Ritonavir/uso terapêutico , Pessoa de Meia-Idade , Hidroxilaminas/uso terapêutico , Citidina/análogos & derivados , Citidina/uso terapêutico , COVID-19/mortalidade , COVID-19/epidemiologia , Antivirais/uso terapêutico , Leucina/análogos & derivados , Leucina/uso terapêutico , Idoso , SARS-CoV-2/isolamento & purificação , Prolina/análogos & derivados , Prolina/uso terapêutico , Indóis/uso terapêutico , Adulto , Pandemias , Fatores de Risco , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/mortalidade , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Betacoronavirus , Lactamas , Nitrilas
5.
Sci Adv ; 10(19): eadl3549, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38718121

RESUMO

Metabolic reprogramming is critical in the onset of pressure overload-induced cardiac remodeling. Our study reveals that proline dehydrogenase (PRODH), the key enzyme in proline metabolism, reprograms cardiomyocyte metabolism to protect against cardiac remodeling. We induced cardiac remodeling using transverse aortic constriction (TAC) in both cardiac-specific PRODH knockout and overexpression mice. Our results indicate that PRODH expression is suppressed after TAC. Cardiac-specific PRODH knockout mice exhibited worsened cardiac dysfunction, while mice with PRODH overexpression demonstrated a protective effect. In addition, we simulated cardiomyocyte hypertrophy in vitro using neonatal rat ventricular myocytes treated with phenylephrine. Through RNA sequencing, metabolomics, and metabolic flux analysis, we elucidated that PRODH overexpression in cardiomyocytes redirects proline catabolism to replenish tricarboxylic acid cycle intermediates, enhance energy production, and restore glutathione redox balance. Our findings suggest PRODH as a modulator of cardiac bioenergetics and redox homeostasis during cardiac remodeling induced by pressure overload. This highlights the potential of PRODH as a therapeutic target for cardiac remodeling.


Assuntos
Camundongos Knockout , Miócitos Cardíacos , Prolina , Remodelação Ventricular , Animais , Prolina/metabolismo , Miócitos Cardíacos/metabolismo , Camundongos , Ratos , Prolina Oxidase/metabolismo , Prolina Oxidase/genética , Metabolismo Energético , Miocárdio/metabolismo , Miocárdio/patologia , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/etiologia , Modelos Animais de Doenças , Oxirredução , Masculino , Reprogramação Metabólica
6.
PLoS One ; 19(5): e0303145, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38728268

RESUMO

Water stress can adversely affect seed germination and plant growth. Seed osmopriming is a pre-sowing treatment in which seeds are soaked in osmotic solutions to undergo the first stage of germination prior to radicle protrusion. Seed osmopriming enhances germination performance under stressful environmental conditions, making it an effective method to improve plant resistance and yield. This study analyzed the effect of seed osmopriming with polyethylene glycol (PEG) on seed germination and physiological parameters of Coronilla varia L. Priming treatments using 10% to 30% PEG enhanced germination percentage, germination vigor, germination index, vitality index, and seedling mass and reduced the time to reach 50% germination (T50). The PEG concentration that led to better results was 10%. The content of soluble proteins (SP), proline (Pro), soluble sugars (SS), and malondialdehyde (MDA) in Coronilla varia L. seedlings increased with the severity of water stress. In addition, under water stress, electrolyte leakage rose, and peroxidase (POD) and superoxide dismutase (SOD) activities intensified, while catalase (CAT) activity increased at mild-to-moderate water stress but declined with more severe deficiency. The 10% PEG priming significantly improved germination percentage, germination vigor, germination index, vitality index, and time to 50% germination (T50) under water stress. Across the water stress gradient here tested (8 to 12% PEG), seed priming enhanced SP content, Pro content, and SOD activity in Coronilla varia L. seedlings compared to the unprimed treatments. Under 10% PEG-induced water stress, primed seedlings displayed a significantly lower MDA content and electrolyte leakage than their unprimed counterparts and exhibited significantly higher CAT and POD activities. However, under 12% PEG-induced water stress, differences in electrolyte leakage, CAT activity, and POD activity between primed and unprimed treatments were not significant. These findings suggest that PEG priming enhances the osmotic regulation and antioxidant capacity of Coronilla varia seedlings, facilitating seed germination and seedling growth and alleviating drought stress damage, albeit with reduced efficacy under severe water deficiency.


Assuntos
Germinação , Polietilenoglicóis , Plântula , Sementes , Polietilenoglicóis/farmacologia , Germinação/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Desidratação , Catalase/metabolismo , Malondialdeído/metabolismo , Prolina/metabolismo , Superóxido Dismutase/metabolismo , Água/metabolismo
7.
Physiol Plant ; 176(3): e14319, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38693848

RESUMO

Amino acids play important roles in stress resistance, plant growth, development, and quality, with roots serving as the primary organs for drought response. We conducted biochemical and multi-omics analyses to investigate the metabolic processes of root amino acids in drought-resistant (HN44) and drought-sensitive (HN65) soybean (Glycine max) varieties. Our analysis revealed an increase in total amino acid content in both varieties, with phenylalanine, proline, and methionine accumulating in both. Additionally, several amino acids exhibited significant decreases in HN65 but slight increases in HN44. Multi-omics association analysis identified 13 amino acid-related pathways. We thoroughly examined the changes in genes and metabolites involved in various amino acid metabolism/synthesis and determined core genes and metabolites through correlation networks. The phenylalanine, tyrosine, and tryptophan metabolic pathways and proline, glutamic acid and sulfur-containing amino acid pathways were particularly important for drought resistance. Some candidate genes, such as ProDH and P4HA family genes, and metabolites, such as O-acetyl-L-serine, directly affected up- and downstream metabolism to induce drought resistance. This study provided a basis for soybean drought resistance breeding.


Assuntos
Aminoácidos , Secas , Glycine max , Raízes de Plantas , Estresse Fisiológico , Glycine max/genética , Glycine max/metabolismo , Glycine max/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Aminoácidos/metabolismo , Regulação da Expressão Gênica de Plantas , Prolina/metabolismo , Reprogramação Metabólica
8.
Biochim Biophys Acta Gen Subj ; 1868(7): 130633, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38762030

RESUMO

BACKGROUND: Drought and water stress impose major limitations to crops, including Maize, as they affect the plant biology at multiple levels. Drought activates the cellular signalling machinery to maintain the osmotic and ROS homeostasis for controlling plant response and adaptation to stress. Molecular priming of seeds plays a significant role in imparting stress tolerance by helping plants to remember the stress, which improves their response when they encounter stress again. METHODS: In this study, we examined the effect of priming maize seeds with H2O2 and proline, individually or in combination, on response to drought stress. We investigated the role of molecular priming on the physiological, biochemical and molecular response of maize seedlings during drought stress. RESULTS: We observed that seed-priming played a significant role in mediating stress tolerance of seedlings under drought stress as indicated by changes in growth, biochemical properties, pigment and osmolyte accumulation, antioxidant enzyme activities, gas exchange parameters and gene expression. Seed-priming resulted in reduced expression of specific miRNAs to increase target transcripts associated with synthesis of osmolytes and maintenance of ROS homeostasis for reducing potential damage to the cellular components. CONCLUSIONS: Seed-priming induced changes in the growth, biochemical properties, pigment and osmolyte accumulation, antioxidant enzyme activities, gas exchange parameters and gene expression, though the response was dependent on the genotype, as well as concentration and combination of the priming agents.


Assuntos
Antioxidantes , Secas , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio , Prolina , Plântula , Estresse Fisiológico , Zea mays , Zea mays/metabolismo , Zea mays/genética , Plântula/metabolismo , Peróxido de Hidrogênio/metabolismo , Prolina/metabolismo , Antioxidantes/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Sementes/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
9.
Int J Mol Sci ; 25(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38791538

RESUMO

Various studies have shown that Hypogymnia physodes are a source of many biologically active compounds, including lichen acids. These lichen-specific compounds are characterized by antioxidant, antiproliferative, and antimicrobial properties, and they can be used in the cosmetic and pharmaceutical industries. The main aim of this study was to optimize the composition of natural deep eutectic solvents based on proline or betaine and lactic acid for the extraction of metabolites from H. physodes. The design of the experimental method and the response surface approach allowed the optimization of the extraction process of specific lichen metabolites. Based on preliminary research, a multivariate model of the experiment was developed. For optimization, the following parameters were employed in the experiment to confirm the model: a proline/lactic acid/water molar ratio of 1:2:2. Such a mixture allowed the efficient extraction of three depsidones (i.e., physodic acid, physodalic acid, 3-hydroyphysodic acid) and one depside (i.e., atranorin). The developed composition of the solvent mixtures ensured good efficiency when extracting the metabolites from the thallus of H. physodes with high antioxidant properties.


Assuntos
Depsídeos , Lactonas , Depsídeos/química , Depsídeos/isolamento & purificação , Depsídeos/farmacologia , Lactonas/química , Lactonas/isolamento & purificação , Lactonas/farmacologia , Solventes Eutéticos Profundos/química , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/isolamento & purificação , Prolina/química , Líquens/química , Ácido Láctico/química , Química Verde/métodos , Betaína/química , Betaína/análogos & derivados , Betaína/farmacologia , Solventes/química , Dibenzoxepinas , Hidroxibenzoatos
10.
Int J Mol Sci ; 25(10)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38791607

RESUMO

This work investigated the cocatalytic activity of recently prepared guanidinium salts containing an oxanorbornane subunit in an (S)-proline-catalyzed aldol reaction. The activity was interpreted by the diastereoselectivity of the reaction (anti/syn ratio) and for the most interesting polycyclic guanidinium salt, the enantioselectivity of the reaction was determined. The results indicated a negative impact on the oxanorbornane unit if present as the flexible substituent. For most of the tested aldehydes, the best cocatalysts provided enantioselectivities above 90% and above 95% at room temperature and 0 °C, respectively, culminating in >99.5% for 4-chloro- and 2-nitrobenzaldehyde as the substrate. The barriers for forming four possible enantiomers were calculated and the results for two anti-enantiomers are qualitatively consistent with the experiment. Obtained results suggest that the representatives of furfurylguanidinium and rigid polycyclic oxanorbornane-substituted guanidinium salts are good lead structures for developing new cocatalysts by tuning the chemical space around the guanidine moiety.


Assuntos
Guanidinas , Prolina , Catálise , Prolina/química , Guanidinas/química , Estereoisomerismo , Aldeídos/química , Norbornanos/química , Guanidina/química , Estrutura Molecular
11.
PLoS One ; 19(5): e0299424, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38781172

RESUMO

Mutations in the non-structural protein regions of hepatitis C virus (HCV) are a cause of a non-sustained virological response (SVR) to treatment with direct-acting antivirals (DAAs) for chronic hepatitis; however, there are non-SVR cases without these mutations. In this study, we examined immune cell profiles in peripheral blood before and after ombitasvir/paritaprevir/ritonavir treatment and screened for genes that could be used to predict the therapeutic effects of DAAs. Fluorescence-activated cell sorting analysis indicated that the median frequencies of programmed cell death-1-positive (PD-1+) effector regulatory T cells (eTregs), PD-1+CD8+ T cells, and PD-1+Helper T cells were decreased significantly in SVR cases, but without significant changes in non-SVR cases. The frequency of PD-1+ naïve Tregs was significantly higher in the SVR group than in the non-SVR group before and after treatment. Similar results were found in patients treated with other DAAs (e.g., daclatasvir plus asunaprevir) and supported an immune response after HCV therapy. RNA-sequencing analysis indicated a significant increase in the expression of genes associated with the immune response in the SVR group, while genes related to intracellular and extracellular signal transduction were highly expressed in the non-SVR group. Therefore, we searched for genes associated with PD-1+ eTregs and CD8+ T cells that were significantly different between the SVR and non-SVR groups and found that T-box transcription factor 21 was associated with the non-SVR state. These results indicate that PD-1-related signaling pathways are associated with a non-SVR mechanism after DAAs treatment separate from mutation-related drug resistance.


Assuntos
Antivirais , Linfócitos T CD8-Positivos , Carbamatos , Hepacivirus , Hepatite C Crônica , Receptor de Morte Celular Programada 1 , Sulfonamidas , Linfócitos T Reguladores , Humanos , Antivirais/uso terapêutico , Masculino , Hepacivirus/efeitos dos fármacos , Hepacivirus/imunologia , Hepacivirus/genética , Feminino , Pessoa de Meia-Idade , Carbamatos/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Linfócitos T Reguladores/imunologia , Sulfonamidas/uso terapêutico , Sulfonamidas/farmacologia , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Hepatite C Crônica/sangue , Ciclopropanos/uso terapêutico , Valina/análogos & derivados , Prolina/análogos & derivados , Anilidas/uso terapêutico , Anilidas/farmacologia , Lactamas Macrocíclicas/uso terapêutico , Compostos Macrocíclicos/uso terapêutico , Compostos Macrocíclicos/farmacologia , Idoso , Ritonavir/uso terapêutico , Adulto , Quimioterapia Combinada , Linfócitos T Auxiliares-Indutores/imunologia , Imidazóis , Isoquinolinas , Pirrolidinas
12.
Sci Rep ; 14(1): 10244, 2024 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702350

RESUMO

Access to Hepatis C treatment in Sub-Saharan Africa is a clinical, public health and ethical concern. The multi-country open-label trial TAC ANRS 12311 allowed assessing the feasibility, safety, efficacy of a specific care model of HCV treatment and retreatment in patients with hepatitis C in Sub Saharan Africa. Between November 2015 and March 2017, with follow-up until mid 2019, treatment-naïve patients with HCV without decompensated cirrhosis or liver cancer were recruited to receive 12 week-treatment with either sofosbuvir + ribavirin (HCV genotype 2) or sofosbuvir + ledipasvir (genotype 1 or 4) and retreatment with sofosbuvir + velpatasvir + voxilaprevir in case of virological failure. The primary outcome was sustained virological response at 12 weeks after end of treatment (SVR12). Secondary outcomes included treatment adherence, safety and SVR12 in patients who were retreated due to non-response to first-line treatment. The model of care relied on both viral load assessment and educational sessions to increase patient awareness, adherence and health literacy. The study recruited 120 participants, 36 HIV-co-infected, and 14 cirrhotic. Only one patient discontinued treatment because of return to home country. Neither death nor severe adverse event occurred. SVR12 was reached in 107 patients (89%): (90%) in genotype 1 or 2, and 88% in GT-4. All retreated patients (n = 13) reached SVR12. HCV treatment is highly acceptable, safe and effective under this model of care. Implementation research is now needed to scale up point-of-care HCV testing and SVR assessment, along with community involvement in patient education, to achieve HCV elimination in Sub-Saharan Africa.


Assuntos
Antivirais , Hepacivirus , Sofosbuvir , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , África Central , África Ocidental , Ácidos Aminoisobutíricos , Antivirais/uso terapêutico , Antivirais/efeitos adversos , Benzimidazóis/uso terapêutico , Benzimidazóis/efeitos adversos , Benzopiranos , Carbamatos/uso terapêutico , Ciclopropanos/uso terapêutico , Ciclopropanos/efeitos adversos , Quimioterapia Combinada , Estudos de Viabilidade , Fluorenos/uso terapêutico , Fluorenos/efeitos adversos , Genótipo , Hepacivirus/genética , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Compostos Heterocíclicos de 4 ou mais Anéis/efeitos adversos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Prolina/análogos & derivados , Prolina/uso terapêutico , Quinoxalinas , Ribavirina/uso terapêutico , Ribavirina/efeitos adversos , Sofosbuvir/uso terapêutico , Sofosbuvir/efeitos adversos , Sulfonamidas/uso terapêutico , Sulfonamidas/efeitos adversos , Resposta Viral Sustentada , Resultado do Tratamento
13.
Phytochemistry ; 224: 114143, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38762153

RESUMO

Cassava (Manihot esculenta Crantz), a crucial global tuber crop, encounters significant economic losses attributed to postharvest physiological deterioration (PPD). The PPD phenomenon in cassava is closely related to the accumulation of reactive oxygen species (ROS), and amino acids play a pivotal role in regulating signaling pathways and eliminating ROS. In this study, the storage performance of eight cassava varieties were conducted. Cassava cultivar SC5 showed the best storage performance among the eight cassava varieties, but the edible cassava cultivar SC9 performed much worse. Comparative analysis of free amino acids was conducted in eight cassava varieties, revealing changes in proline, aspartic acid, histidine, glutamic acid, threonine, and serine. Exogenous supplementation of these six amino acids was performed to inhibit PPD of SC9. Proline was confirmed as the key amino acid for inhibiting PPD. Treatment with optimal exogenous proline of 5 g/L resulted in a 17.9% decrease in the deterioration rate compared to untreated cassava. Accompanied by a decrease in H2O2 content and an increase in catalase, superoxide dismutase and ascorbate peroxidase activity. Proline treatment proved to be an effective approach to alleviate cell oxidative damage, inhibit PPD in cassava, and prolong shelf life.


Assuntos
Antioxidantes , Manihot , Prolina , Manihot/química , Prolina/farmacologia , Prolina/metabolismo , Prolina/química , Antioxidantes/farmacologia , Antioxidantes/química , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia
14.
Transgenic Res ; 33(3): 131-147, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38739244

RESUMO

Δ1-pyrroline-5-carboxylate synthetase (P5CS) is one of the key regulatory enzymes involved in the proline biosynthetic pathway. Proline acts as an osmoprotectant, molecular chaperone, antioxidant, and regulator of redox homeostasis. The accumulation of proline during stress is believed to confer tolerance in plants. In this study, we cloned the complete CDS of the P5CS from pearl millet (Pennisetum glaucum (L.) R.Br. and transformed into tobacco. Three transgenic tobacco plants with single-copy insertion were analyzed for drought and heat stress tolerance. No difference was observed between transgenic and wild-type (WT) plants when both were grown in normal conditions. However, under heat and drought, transgenic plants have been found to have higher chlorophyll, relative water, and proline content, and lower malondialdehyde (MDA) levels than WT plants. The photosynthetic parameters (stomatal conductance, intracellular CO2 concentration, and transpiration rate) were also observed to be high in transgenic plants under abiotic stress conditions. qRT-PCR analysis revealed that the expression of the transgene in drought and heat conditions was 2-10 and 2-7.5 fold higher than in normal conditions, respectively. Surprisingly, only P5CS was increased under heat stress conditions, indicating the possibility of feedback inhibition. Our results demonstrate the positive role of PgP5CS in enhancing abiotic stress tolerance in tobacco, suggesting its possible use to increase abiotic stress-tolerance in crops for sustained yield under adverse climatic conditions.


Assuntos
Secas , Nicotiana , Plantas Geneticamente Modificadas , Prolina , Estresse Fisiológico , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Nicotiana/genética , Nicotiana/metabolismo , Estresse Fisiológico/genética , Prolina/metabolismo , Pennisetum/genética , Pennisetum/metabolismo , Regulação da Expressão Gênica de Plantas , Fotossíntese/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Clorofila/metabolismo
15.
Biomacromolecules ; 25(6): 3661-3670, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38807574

RESUMO

Rotaxane cross-linkers enhance the toughness of the resulting rotaxane cross-linked polymers through a stress dispersion effect, which is attributed to the mobility of the interlocked structure. To date, the compositional diversity of rotaxane cross-linkers has been limited, and the poor compatibility of these cross-linkers with peptides and proteins has made their use in such materials challenging. The synthesis of a rotaxane composed of peptides may result in a biodegradable cross-linker that is compatible with peptides and proteins, allowing the fortification of polypeptides and proteins and ultimately leading to the development of innovative materials that possess excellent mechanical properties and biodegradability. However, the chemical synthesis of all-peptide-based rotaxanes has remained elusive because of the absence of strong binding motifs in peptides, which prevents an axial peptide from penetrating a cyclic peptide. Here, we synthesized all-peptide-based rotaxanes using an active template method for proline-containing cyclic peptides. The results of molecular dynamics simulations suggested that cyclic peptides with an expansive inner cavity and carbonyl oxygens oriented toward the center are favorable for rotaxane synthesis. This rotaxane synthesis method is expected to accelerate the synthesis of peptides and proteins with mechanically interlocked structures, potentially leading to the development of peptide- and protein-based materials with unprecedented functionalities.


Assuntos
Peptídeos Cíclicos , Prolina , Rotaxanos , Rotaxanos/química , Rotaxanos/síntese química , Prolina/química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/síntese química , Simulação de Dinâmica Molecular
16.
Environ Sci Pollut Res Int ; 31(23): 34028-34037, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38693456

RESUMO

Phytoremediation has become famous for removing particulate matter (PM) and volatile organic compounds (VOC) in situ. Plants for removing PM and VOC were associated with botanical biofilters to attract pollution to the plant. On the other hand, persistent pollution exposure can lower plant health and phytoremediation effectiveness; therefore, improving plant tolerance against stress is necessary. Various elicitors can enhance plant tolerance to certain stressors. This study aims to investigate different elicitors to maintain plant health and improve the use of plants in phytoremediation for PM and VOC pollution. This experiment used Sansevieria trifasciata hort. ex Prain under PM and VOC stress. Exogenous elicitors, such as proline, ornithine, and a commercial product, were applied to the leaf parts before exposure to PM and VOC stress. The initial concentrations of PM1, PM2.5, and PM10 were 300-350, 350-450, and 400-500 µg m-3, respectively, while the VOC concentration was 2.5-3.0 mg m-3. The plant was stressed for 7 days. The result indicated that ornithine 10 mM is vital in improving plant tolerance and inducing antioxidant enzymes against PM and VOC, while proline 50 mM and a commercial product could not reduce plant stress. This study suggests that ornithine might be an important metabolite to improve plant tolerance to PM and VOC.


Assuntos
Biodegradação Ambiental , Ornitina , Material Particulado , Prolina , Compostos Orgânicos Voláteis , Prolina/metabolismo
17.
Molecules ; 29(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38792190

RESUMO

As a conformationally restricted amino acid, hydroxy-l-proline is a versatile scaffold for the synthesis of diverse multi-functionalized pyrrolidines for probing the ligand binding sites of biological targets. With the goal to develop new inhibitors of the widely expressed amino acid transporters SLC1A4 and SLC1A5 (also known as ASCT1 and ASCT2), we synthesized and functionally screened synthetic hydroxy-l-proline derivatives using electrophysiological and radiolabeled uptake methods against amino acid transporters from the SLC1, SLC7, and SLC38 solute carrier families. We have discovered a novel class of alkoxy hydroxy-pyrrolidine carboxylic acids (AHPCs) that act as selective high-affinity inhibitors of the SLC1 family neutral amino acid transporters SLC1A4 and SLC1A5. AHPCs were computationally docked into a homology model and assessed with respect to predicted molecular orientation and functional activity. The series of hydroxyproline analogs identified here represent promising new agents to pharmacologically modulate SLC1A4 and SLC1A5 amino acid exchangers which are implicated in numerous pathophysiological processes such as cancer and neurological diseases.


Assuntos
Sistema ASC de Transporte de Aminoácidos , Antígenos de Histocompatibilidade Menor , Sistema ASC de Transporte de Aminoácidos/antagonistas & inibidores , Sistema ASC de Transporte de Aminoácidos/metabolismo , Sistema ASC de Transporte de Aminoácidos/química , Antígenos de Histocompatibilidade Menor/metabolismo , Antígenos de Histocompatibilidade Menor/química , Humanos , Prolina/química , Prolina/análogos & derivados , Animais , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Células HEK293 , Pirrolidinas/química , Pirrolidinas/farmacologia , Pirrolidinas/síntese química , Descoberta de Drogas , Sistemas de Transporte de Aminoácidos Neutros/antagonistas & inibidores , Sistemas de Transporte de Aminoácidos Neutros/química , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/genética
18.
Planta ; 259(6): 142, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38702456

RESUMO

MAIN CONCLUSION: PLDα1 promoted H2S production by positively regulating the expression of LCD. Stomatal closure promoted by PLDα1 required the accumulation of H2S under drought stress. Phospholipase Dα1 (PLDα1) acting as one of the signal enzymes can respond to drought stress. It is well known that hydrogen sulfide (H2S) plays an important role in plant responding to biotic or abiotic stress. In this study, the functions and relationship between PLDα1 and H2S in drought stress resistance in Arabidopsis were explored. Our results indicated that drought stress promotes PLDα1 and H2S production by inducing the expression of PLDα1 and LCD genes. PLDα1 and LCD enhanced plant tolerance to drought by regulating membrane lipid peroxidation, proline accumulation, H2O2 content and stomatal closure. Under drought stress, the H2O2 content of PLDα1-deficient mutant (pldα1), L-cysteine desulfhydrase (LCD)-deficient mutant (lcd) was higher than that of ecotype (WT), the stomatal aperture of pldα1 and lcd was larger than that of WT. The transcriptional and translational levels of LCD were lower in pldα1 than that in WT. Exogenous application of the H2S donor NaHS or GYY reduced the stomatal aperture of WT, pldα1, PLDα1-CO, and PLDα1-OE lines, while exogenous application of the H2S scavenger hypotaurine (HT) increased the stomatal aperture. qRT-PCR analysis of stomatal movement-related genes showed that the expression of CAX1, ABCG5, SCAB1, and SLAC1 genes in pldα1 and lcd were down-regulated, while ACA1 and OST1 gene expression was significantly up-regulated. Thus, PLDα1 and LCD are required for stomatal closure to improve drought stress tolerance.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Secas , Regulação da Expressão Gênica de Plantas , Sulfeto de Hidrogênio , Fosfolipase D , Estômatos de Plantas , Arabidopsis/genética , Arabidopsis/fisiologia , Estômatos de Plantas/fisiologia , Estômatos de Plantas/genética , Fosfolipase D/metabolismo , Fosfolipase D/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sulfeto de Hidrogênio/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Fisiológico/genética , Prolina/metabolismo , Cistationina gama-Liase/genética , Cistationina gama-Liase/metabolismo , Peroxidação de Lipídeos
19.
Nat Commun ; 15(1): 3888, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719828

RESUMO

PRPF40A plays an important role in the regulation of pre-mRNA splicing by mediating protein-protein interactions in the early steps of spliceosome assembly. By binding to proteins at the 5´ and 3´ splice sites, PRPF40A promotes spliceosome assembly by bridging the recognition of the splices. The PRPF40A WW domains are expected to recognize proline-rich sequences in SF1 and SF3A1 in the early spliceosome complexes E and A, respectively. Here, we combine NMR, SAXS and ITC to determine the structure of the PRPF40A tandem WW domains in solution and characterize the binding specificity and mechanism for proline-rich motifs recognition. Our structure of the PRPF40A WW tandem in complex with a high-affinity SF1 peptide reveals contributions of both WW domains, which also enables tryptophan sandwiching by two proline residues in the ligand. Unexpectedly, a proline-rich motif in the N-terminal region of PRPF40A mediates intramolecular interactions with the WW tandem. Using NMR, ITC, mutational analysis in vitro, and immunoprecipitation experiments in cells, we show that the intramolecular interaction acts as an autoinhibitory filter for proof-reading of high-affinity proline-rich motifs in bona fide PRPF40A binding partners. We propose that similar autoinhibitory mechanisms are present in most WW tandem-containing proteins to enhance binding selectivity and regulation of WW/proline-rich peptide interaction networks.


Assuntos
Prolina , Ligação Proteica , Domínios WW , Humanos , Motivos de Aminoácidos , Modelos Moleculares , Prolina/metabolismo , Prolina/química , Splicing de RNA , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de RNA/química , Fatores de Processamento de RNA/genética , Espalhamento a Baixo Ângulo , Spliceossomos/metabolismo , Difração de Raios X
20.
PeerJ ; 12: e17372, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38770096

RESUMO

Quantifying the tropic position (TP) of an animal species is key to understanding its ecosystem function. While both bulk and compound-specific analyses of stable isotopes are widely used for this purpose, few studies have assessed the consistency between and within such approaches. Champsocephalus gunnari is a specialist teleost that predates almost exclusively on Antarctic krill Euphausia superba. This well-known and nearly constant trophic relationship makes C. gunnari particularly suitable for assessing consistency between TP methods under field conditions. In the present work, we produced and compared TP estimates for C. gunnari and its main prey using a standard bulk and two amino acid-specific stable isotope approaches (CSI-AA). One based on the difference between glutamate and phenylalanine (TPGlx-Phe), and the other on the proline-phenylalanine difference (TPPro-Phe). To do that, samples from C. gunnari, E. superba and four other pelagic invertebrate and fish species, all potential prey for C.gunnari, were collected off the South Orkney Islands between January and March 2019, analyzed using standard isotopic ratio mass spectrometry methods and interpreted following a Bayesian approach. Median estimates (CI95%) for C. gunnari were similar between TPbulk (3.6; CI95%: 3.0-4.8) and TPGlx-Phe(3.4; CI95%:3.2-3.6), and lower for TPPro-Phe (3.1; CI95%:3.0-3.3). TP differences between C. gunnari and E. superba were 1.4, 1.1 and 1.2, all compatible with expectations from the monospecific diet of this predator (ΔTP=1). While these results suggest greater accuracy for Glx-Phe and Pro-Phe, differences observed between both CSI-AA approaches suggests these methods may require further validation before becoming a standard tool for trophic ecology.


Assuntos
Cadeia Alimentar , Perciformes , Animais , Perciformes/metabolismo , Fenilalanina/análise , Fenilalanina/metabolismo , Regiões Antárticas , Euphausiacea/química , Ecossistema , Teorema de Bayes , Ácido Glutâmico/análise , Ácido Glutâmico/metabolismo , Prolina/análise
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