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1.
Nutrients ; 11(10)2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31640267

RESUMO

The standard treatment for phenylketonuria (PKU) is a lifelong low-phenylalanine (Phe) diet, supplemented with Phe-free protein substitutes; however, adult patients often show poor adherence to therapy. Alternative treatment options include the use of large neutral amino acids (LNAA). The aim of this study was to determine the Phe, tyrosine (Tyr), and Phe/Tyr ratio in a cohort of sub-optimally controlled adult patients with classical PKU treated with a new LNAA formulation. Twelve patients received a Phe-restricted diet plus a slow-release LNAA product taken three times per day, at a dose of 1 g/kg body weight (mean 0.8 ± 0.24 g/kg/day), over a 12-month period. The product is in a microgranulated formulation, which incorporates all amino acids and uses sodium alginate as a hydrophilic carrier to prolong its release. This LNAA formulation provides up to 80% of the total protein requirement, with the rest of the protein supplied by natural food. Patients had fortnightly measurements of Phe and Tyr levels over a 12-month period after the introduction of LNAA. All patients completed the 12-month treatment period. Overall, adherence to the new LNAA tablets was very good compared with a previous amino acid mixture, for which taste was a major complaint by patients. Phe levels remained unchanged (p = 0.0522), and Tyr levels increased (p = 0.0195). Consequently, the Phe/Tyr ratio decreased significantly (p < 0.05) in the majority of patients treated. In conclusion, LNAA treatment increases Tyr levels in sub-optimally controlled adult PKU patients, while offering the potential to improve their adherence to treatment.


Assuntos
Aminoácidos Neutros/uso terapêutico , Fenilalanina/sangue , Fenilcetonúrias/sangue , Fenilcetonúrias/tratamento farmacológico , Tirosina/sangue , Adulto , Barreira Hematoencefálica , Dieta , Suplementos Nutricionais , Feminino , Humanos , Itália , Masculino , Cooperação do Paciente , Satisfação do Paciente , Fenilalanina/administração & dosagem , Fenilcetonúrias/dietoterapia , Paladar , Adulto Jovem
2.
Nutrients ; 11(10)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623189

RESUMO

Tyrosinemia type 1 (TT1) is a rare metabolic disease caused by a defect in the tyrosine degradation pathway. Neurocognitive deficiencies have been described in TT1 patients, that have, among others, been related to changes in plasma large neutral amino acids (LNAA) that could result in changes in brain LNAA and neurotransmitter concentrations. Therefore, this project aimed to investigate plasma and brain LNAA, brain neurotransmitter concentrations and behavior in C57 Bl/6 fumarylacetoacetate hydrolase deficient (FAH-/-) mice treated with 2-(2-nitro-4-trifluoromethylbenoyl)-1,3-cyclohexanedione (NTBC) and/or diet and wild-type mice. Plasma and brain tyrosine concentrations were clearly increased in all NTBC treated animals, even with diet (p < 0.001). Plasma and brain phenylalanine concentrations tended to be lower in all FAH-/- mice. Other brain LNAA, were often slightly lower in NTBC treated FAH-/- mice. Brain neurotransmitter concentrations were usually within a normal range, although serotonin was negatively correlated with brain tyrosine concentrations (p < 0.001). No clear behavioral differences between the different groups of mice could be found. To conclude, this is the first study measuring plasma and brain biochemistry in FAH-/- mice. Clear changes in plasma and brain LNAA have been shown. Further research should be done to relate the biochemical changes to neurocognitive impairments in TT1 patients.


Assuntos
Aminoácidos Neutros/sangue , Comportamento Animal/efeitos dos fármacos , Monoaminas Biogênicas/metabolismo , Encéfalo/efeitos dos fármacos , Cicloexanonas/farmacologia , Dieta com Restrição de Proteínas , Inibidores Enzimáticos/farmacologia , Ácido Hidroxi-Indolacético/metabolismo , Nitrobenzoatos/farmacologia , Tirosinemias/terapia , Ração Animal , Animais , Biomarcadores/sangue , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Feminino , Hidrolases/deficiência , Hidrolases/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tirosinemias/sangue , Tirosinemias/fisiopatologia , Tirosinemias/psicologia
3.
Nutrients ; 11(9)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546852

RESUMO

Many phenylketonuria (PKU) patients cannot adhere to the severe dietary restrictions as advised by the European PKU guidelines, which can be accompanied by aggravated neuropsychological impairments that, at least in part, have been attributed to brain monoaminergic neurotransmitter deficiencies. Supplementation of large neutral amino acids (LNAA) to an unrestricted diet has previously been shown to effectively improve brain monoamines in PKU mice of various ages. To determine the additive value of LNAA supplementation to a liberalized phenylalanine-restricted diet, brain and plasma monoamine and amino acid concentrations in 10 to 16-month-old adult C57Bl/6 PKU mice on a less severe phenylalanine-restricted diet with LNAA supplementation were compared to those on a non-supplemented severe or less severe phenylalanine-restricted diet. LNAA supplementation to a less severe phenylalanine-restricted diet was found to improve both brain monoamine and phenylalanine concentrations. Compared to a severe phenylalanine-restricted diet, it was equally effective to restore brain norepinephrine and serotonin even though being less effective to reduce brain phenylalanine concentrations. These results in adult PKU mice support the idea that LNAA supplementation may enhance the effect of a less severe phenylalanine-restricted diet and suggest that cerebral outcome of PKU patients treated with a less severe phenylalanine-restricted diet may be helped by additional LNAA treatment.


Assuntos
Aminoácidos Neutros/administração & dosagem , Dieta , Fenilalanina/administração & dosagem , Fenilcetonúrias/dietoterapia , Ração Animal/análise , Animais , Encéfalo/metabolismo , Suplementos Nutricionais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
4.
Enzyme Microb Technol ; 128: 72-78, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31186113

RESUMO

Glutaric acid is an attractive C5 dicarboxylic acid with wide applications in the biochemical industry. Glutaric acid can be produced by fermentation and bioconversion, and several of its biosynthesis pathways have been well characterized, especially the simple pathway involving glutaric acid from l-lysine using 5-aminovaleric acid. We previously reported the production of glutaric acid using 5-aminovaleric acid and α-ketoglutaric acid by a whole-cell reaction, resulting in a high conversion yield. In this study, we sought to enhance the stability and reusability of this whole-cell system for realizing the efficient production of glutaric acid under harsh reaction conditions. To this end, various matrices were screened to immobilize Escherichia coli whole-cell overexpressing 4-aminobutyrate aminotransferase (GabT), succinate semi-aldehyde dehydrogenase (GabD), and NAD(P)H oxidase (NOX). We ultimately selected a PVA-PEG gel (LentiKats®) for cell entrapment, and several factors of the reaction were optimized. The optimal temperature and pH were 35 °C and 8.5, respectively. Treatment with Tween 80 as a surfactant, as well as additional NOX, was found to be effective. Under the optimized conditions, an immobilized cell retained 55% of its initial activity even after the eighth cycle, achieving 995.2 mM accumulated glutaric acid, whereas free cell lost most of their activity after only two cycles. This optimized whole-cell system can be used in the large-scale production of glutaric acid.


Assuntos
Aminoácidos Neutros/metabolismo , Células Imobilizadas/metabolismo , Escherichia coli/metabolismo , Glutaratos/metabolismo , Biotransformação , Escherichia coli/enzimologia , Géis , Concentração de Íons de Hidrogênio , Polietilenoglicóis , Álcool de Polivinil , Temperatura
5.
J Anim Sci ; 97(6): 2505-2514, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30959521

RESUMO

A meta-analysis was conducted to evaluate the effects of branched-chain amino acids (BCAA), their interactions, and interactions with large neutral amino acids (LNAA) to develop prediction equations for growth performance of pigs. Data from 25 papers, published from 1995 to 2018, for a total of 44 trials and 210 observations were recorded in a database. Diets were reformulated using the NRC (2012) loading values to estimate nutrient concentrations. The response variables were average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). The predictor variables tested included average body weight (BW), crude protein, neutral detergent fiber, Ile:Lys, Leu:Lys, Val:Lys, BCAA:Lys, Ile:Leu, Val:Leu, Ile:Val, (Ile+Val):Leu, Trp:Lys, Leu:Trp, Ile:Trp, Val:Trp, BCAA:Trp, Met:Lys, Leu:Met, Ile:Met, Val:Met, BCAA:Met, His:Lys, Leu:His, Ile:His, Val:His, BCAA:His, Thr:Lys, Leu:Thr, Ile:Thr, Val:Thr, BCAA:Thr, (Phe+Tyr):Lys, Leu:(Phe+Tyr), Ile:(Phe+Tyr), Val:(Phe+Tyr), BCAA:(Phe+Tyr), LNAA:Lys, Leu:LNAA, Ile:LNAA, Val:LNAA, and BCAA:LNAA. Amino acids were expressed on standardized ileal digestible basis. The MIXED procedure of SAS (SAS Institute Inc., Cary, NC) was used to develop the equations. The inverse of squared SEM was used to account for heterogeneous errors using the WEIGHT statement. Models were selected with a step-wise manual forward selection. In order to be included in the final model, predictor variables had to be statistically significant (P < 0.05) and provide an improvement of at least 2 points in Bayesian information criterion. The optimum equations were: ADG, g = - 985.94 + (15.2499 × average BW (kg)) - (0.08885 × average BW × average BW) + (1.063 × Leu:Lys) + (20.2659 × Ile:Lys) - (0.1479 × Ile:Lys × Ile:Lys) + (9.2243 × (Ile+Val):Leu) - (0.03321 × (Ile+Val):Leu × (Ile+Val):Leu) - (0.4413 × Ile:Trp); G:F, g/kg = 648.3 - (6.2974 × average BW (kg)) + (0.02051 × average BW × average BW) + (0.5396 × Ile:Lys) + (1.7284 × Val:Lys) - (0.00795 × Val:Lys × Val:Lys) - (1.7594 × Met:Lys); and ADFI, kg = predicted ADG/predicted G:F. Overall, the prediction equations suggest that increasing Leu:Lys negatively impacts ADG due to a reduction in G:F and ADFI caused by insufficient levels of other BCAA and LNAA relative to Leu. According to the model, the addition of Val, Ile, and Trp, alone or in combination, has the potential to counteract the negative effects of high dietary Leu concentrations on growth performance.


Assuntos
Aminoácidos/farmacologia , Ração Animal/análise , Suínos/fisiologia , Aminoácidos de Cadeia Ramificada/farmacologia , Aminoácidos Neutros/farmacologia , Animais , Teorema de Bayes , Peso Corporal/efeitos dos fármacos , Dieta/veterinária , Íleo/metabolismo , Análise de Regressão , Suínos/crescimento & desenvolvimento
6.
Toxins (Basel) ; 11(3)2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893830

RESUMO

In vitro experiments have demonstrated that camel foregut-fluid has the capacity to metabolize indospicine, a natural toxin which causes hepatotoxicosis, but such metabolism is in competition with absorption and outflow of indospicine from the different segments of the digestive system. Six young camels were fed Indigofera spicata (337 µg indospicine/kg BW/day) for 32 days, at which time three camels were euthanized. The remaining camels were monitored for a further 100 days after cessation of this indospicine diet. In a retrospective investigation, relative levels of indospicine foregut-metabolism products were examined by UHPLC-MS/MS in plasma, collected during both accumulation and depletion stages of this experiment. The metabolite 2-aminopimelamic acid could be detected at low levels in almost all plasma samples, whereas 2-aminopimelic acid could not be detected. In the euthanized camels, 2-aminopimelamic acid could be found in all tissues except muscle, whereas 2-aminopimelic acid was only found in the kidney, pancreas, and liver tissues. The clearance rate for these metabolites was considerably greater than for indospicine, which was still present in plasma of the remaining camels 100 days after cessation of Indigofera consumption.


Assuntos
Sistema Digestório/metabolismo , Indigofera , Norleucina/análogos & derivados , Aminoácidos Neutros/sangue , Aminoácidos Neutros/metabolismo , Animais , Camelus , Contaminação de Alimentos , Norleucina/sangue , Norleucina/farmacocinética , Ácidos Pimélicos/sangue , Ácidos Pimélicos/metabolismo , Distribuição Tecidual
7.
J Pediatr Endocrinol Metab ; 32(3): 269-274, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30835252

RESUMO

Background Oxidative stress may be one of the causes responsible for mental retardation in phenylketonuria (PKU) patients. Phenylalanine (Phe) reduces antioxidant defense and promotes oxidative stress by causing increase in reactive oxygen-nitrogen species. Our study aimed to investigate the effect of different treatments (amino acid mixture/large neutral amino acid [LNAA] supplements) on oxidative stress which are applied to late-diagnosed patients. To the best of our knowledge, this is the first study to investigate the effect of LNAA supplements on oxidative stress. Methods Twenty late-diagnosed classic PKU patients were included in this study. Patients were classified into two groups: patients under Phe-restricted diet and using Phe-free amino acid mixtures (Group I) (mean age: 13.8 ± 2.8), and patients taking LNAA supplements (Group II) (mean age: 14.8 ± 3.8). Healthy controls (mean age: 13.6 ± 4.8) with ages consistent with the ages of the patients in the experimental groups were included. Results Glutathione peroxidase is lower in patients of taking LNAA supplements than the control group (p = 0.022). Coenzyme Q10 is lower in patients of using Phe-free amino acid mixtures than the control group and it is significantly higher in Group II than Group I (p = 0.0001, p = 0.028, respectively). No significant differences were detected in total antioxidant status, total oxidant status, oxidative stress index, paraoxonase 1 and L-carnitine levels. Conclusions Different treatments affect oxidative stress parameters in PKU patients. In this study, although patients were followed up with classic PKU, patient-specific adjuvant antioxidant therapies should be implemented in response to oxidative stress.


Assuntos
Aminoácidos Neutros/administração & dosagem , Antioxidantes/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Fenilcetonúrias/metabolismo , Adolescente , Criança , Suplementos Nutricionais , Feminino , Humanos , Masculino , Espécies Reativas de Oxigênio/metabolismo , Resultado do Tratamento , Adulto Jovem
8.
Nat Commun ; 9(1): 5071, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30498244

RESUMO

Lysine degradation has remained elusive in many organisms including Escherichia coli. Here we report catabolism of lysine to succinate in E. coli involving glutarate and L-2-hydroxyglutarate as intermediates. We show that CsiD acts as an α-ketoglutarate-dependent dioxygenase catalysing hydroxylation of glutarate to L-2-hydroxyglutarate. CsiD is found widespread in bacteria. We present crystal structures of CsiD in complex with glutarate, succinate, and the inhibitor N-oxalyl-glycine, demonstrating strong discrimination between the structurally related ligands. We show that L-2-hydroxyglutarate is converted to α-ketoglutarate by LhgO acting as a membrane-bound, ubiquinone-linked dehydrogenase. Lysine enters the pathway via 5-aminovalerate by the promiscuous enzymes GabT and GabD. We demonstrate that repression of the pathway by CsiR is relieved upon glutarate binding. In conclusion, lysine degradation provides an important link in central metabolism. Our results imply the gut microbiome as a potential source of glutarate and L-2-hydroxyglutarate associated with human diseases such as cancer and organic acidurias.


Assuntos
Glutaratos/metabolismo , Lisina/metabolismo , Aminoácidos Neutros/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Succinato-Semialdeído Desidrogenase/metabolismo
9.
Sci Rep ; 8(1): 13036, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30158657

RESUMO

Despite epidemiological evidence showing that diets rich in whole grains reduce the risk of chronic life-style related diseases, biological mechanisms for these positive effects are mostly unknown. Increased 5-aminovaleric acid betaine (5-AVAB) levels in plasma and metabolically active tissues such as heart have been associated with consumption of diets rich in whole grains. However, biological effects of 5-AVAB are poorly understood. We evaluated 5-AVAB concentrations in human and mouse heart tissue (3-22 µM and 38-78 µM, respectively) using mass spectrometry. We show that 5-AVAB, at physiological concentration range, dose-dependently inhibits oxygen consumption due to ß-oxidation of fatty acids, but does not otherwise compromise mitochondrial respiration, as measured with oxygen consumption rate in cultured mouse primary cardiomyocytes. We also demonstrate that this effect is caused by 5-AVAB induced reduction of cellular L-carnitine. Reduced L-carnitine levels are at least partly mediated by the inhibition of cell membrane carnitine transporter (OCTN2) as evaluated by in silico docking, and by siRNA mediated silencing of OCTN2 in cultured cardiomyocytes. 5-AVAB caused inhibition of ß-oxidation of fatty acids is a novel mechanism on how diets rich in whole grains may regulate energy metabolism in the body. Elucidating potentially beneficial effects of 5-AVAB e.g. on cardiac physiology will require further in vivo investigations.


Assuntos
Aminoácidos Neutros/análise , Betaína/análise , Dieta/métodos , Ácidos Graxos/metabolismo , Miocárdio/química , Miócitos Cardíacos/fisiologia , Grãos Integrais/metabolismo , Animais , Células Cultivadas , Humanos , Espectrometria de Massas , Camundongos Endogâmicos C57BL , Oxirredução
10.
Enzyme Microb Technol ; 118: 57-65, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30143200

RESUMO

Glutaric acid is one of the promising C5 platform compounds in the biochemical industry. It can be produced chemically, through the ring-opening of butyrolactone followed by hydrolysis. Alternatively, glutaric acid can be produced via lysine degradation pathways by microorganisms. In microorganisms, the overexpression of enzymes involved in this pathway from E. coli and C. glutamicum has resulted in high accumulation of 5-aminovaleric acid. However, the conversion from 5-aminovaleric acid to glutaric acid has resulted in a relatively low conversion yield for unknown reasons. In this study, as a solution to improve the production of glutaric acid, we introduced gabTD genes from B. subtilis to E. coli for a whole cell biocatalytic approach. This approach enabled us to determine the effect of co-factors on reaction and to achieve a high conversion yield from 5-aminovaleric acid at the optimized reaction condition. Optimization of whole cell reaction by different plasmids, pH, temperature, substrate concentration, and cofactor concentration achieved full conversion with 100 mM of 5-aminovaleric acid to glutaric acid. Nicotinamide adenine dinucleotide phosphate (NAD(P)+) and α-ketoglutaric acid were found to be critical factors in the enhancement of conversion in selected conditions. Whole cell reaction with a higher concentration of substrates gave 141 mM of glutaric acid from 300 mM 5-aminovaleric acid, 150 mM α-ketoglutaric acid, and 60 mM NAD+ at 30 °C, with a pH of 8.5 within 24 h (47.1% and 94.2% of conversion based on 5-aminovaleric acid and α-ketoglutaric acid, respectively). The whole cell biocatalyst was recycled 5 times with the addition of substrates; this enabled the accumulation of extra glutaric acid.


Assuntos
4-Aminobutirato Transaminase/metabolismo , Aminoácidos Neutros/metabolismo , Bacillus subtilis/enzimologia , Escherichia coli/metabolismo , Glutaratos/metabolismo , Succinato-Semialdeído Desidrogenase/metabolismo , 4-Aminobutirato Transaminase/genética , Bacillus subtilis/genética , Biocatálise , Escherichia coli/genética , Succinato-Semialdeído Desidrogenase/genética
11.
JCI Insight ; 3(14)2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-30046012

RESUMO

The neuropathological effects of phenylketonuria (PKU) stem from the inability of the body to metabolize excess phenylalanine (Phe), resulting in accumulation of Phe in the blood and brain. Since the kidney normally reabsorbs circulating amino acids with high efficiency, we hypothesized that preventing the renal uptake of Phe might provide a disposal pathway that could lower systemic Phe levels. SLC6A19 is a neutral amino acid transporter responsible for absorption of the majority of free Phe in the small intestine and reuptake of Phe by renal proximal tubule cells. Transgenic KO mice lacking SLC6A19 have elevated levels of Phe and other amino acids in their urine but are otherwise healthy. Here, we crossed the Pahenu2 mouse model of PKU with the Slc6a19-KO mouse. These mutant/KO mice exhibited abundant excretion of Phe in the urine and an approximately 70% decrease in plasma Phe levels. Importantly, brain Phe levels were decreased by 50%, and the levels of key neurotransmitters were increased in the mutant/KO mice. In addition, a deficit in spatial working memory and markers of neuropathology were corrected. Finally, treatment of Pahenu2 mice with Slc6a19 antisense oligonucleotides lowered Phe levels. The results suggest that inhibition of SLC6A19 may represent a novel approach for the treatment of PKU and related aminoacidopathies.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros/análise , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Aminoácidos Neutros/metabolismo , Transporte Biológico/efeitos dos fármacos , Fenilcetonúrias/terapia , Aminas , Sistemas de Transporte de Aminoácidos Neutros/genética , Aminoácidos Neutros/sangue , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Doenças Genéticas Inatas/terapia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Masculino , Memória de Curto Prazo , Camundongos , Camundongos Knockout , Morfolinos/farmacologia , Oligonucleotídeos/farmacologia , Fenilalanina/sangue , Fenilalanina/metabolismo , Fenilcetonúrias/patologia , Reabsorção Renal/efeitos dos fármacos
12.
J Biol Chem ; 293(26): 9945-9957, 2018 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-29743237

RESUMO

The isozymes of photosynthetic phosphoenolpyruvate carboxylase from C4 plants (PEPC-C4) play a critical role in their atmospheric CO2 assimilation and productivity. They are allosterically activated by phosphorylated trioses or hexoses, such as d-glucose 6-phosphate, and inhibited by l-malate or l-aspartate. Additionally, PEPC-C4 isozymes from grasses are activated by glycine, serine, or alanine, but the allosteric site for these compounds remains unknown. Here, we report a new crystal structure of the isozyme from Zea mays (ZmPEPC-C4) with glycine bound at the monomer-monomer interfaces of the two dimers of the tetramer, making interactions with residues of both monomers. This binding site is close to, but different from, the one proposed to bind glucose 6-phosphate. Docking experiments indicated that d/l-serine or d/l-alanine could also bind to this site, which does not exist in the PEPC-C4 isozyme from the eudicot plant Flaveria, mainly because of a lysyl residue at the equivalent position of Ser-100 in ZmPEPC-C4 Accordingly, the ZmPEPC-C4 S100K mutant is not activated by glycine, serine, or alanine. Amino acid sequence alignments showed that PEPC-C4 isozymes from the monocot family Poaceae have either serine or glycine at this position, whereas those from Cyperaceae and eudicot families have lysine. The size and charge of the residue equivalent to Ser-100 are not only crucial for the activation of PEPC-C4 isozymes by neutral amino acids but also affect their affinity for the substrate phosphoenolpyruvate and their allosteric regulation by glucose 6-phosphate and malate, accounting for the reported kinetic differences between PEPC-C4 isozymes from monocot and eudicot plants.


Assuntos
Sítio Alostérico , Aminoácidos Neutros/metabolismo , Fosfoenolpiruvato Carboxilase/química , Fosfoenolpiruvato Carboxilase/metabolismo , Serina/metabolismo , Zea mays/enzimologia , Isoenzimas/química , Isoenzimas/metabolismo , Cinética , Modelos Moleculares , Conformação Proteica , Especificidade por Substrato
13.
J Ind Microbiol Biotechnol ; 45(8): 719-734, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29654382

RESUMO

L-Lysine is widely used as a nutrition supplement in feed, food, and beverage industries as well as a chemical intermediate. At present, great efforts are made to further decrease the cost of lysine to make it more competitive in the markets. Furthermore, lysine also shows potential as a feedstock to produce other high-value chemicals for active pharmaceutical ingredients, drugs, or materials. In this review, the current biomanufacturing of lysine is first presented. Second, the production of novel derivatives from lysine is discussed. Some chemicals like L-pipecolic acid, cadaverine, and 5-aminovalerate already have been obtained at a lab scale. Others like 6-aminocaproic acid, valerolactam, and caprolactam could be produced through a biological and chemical coupling pathway or be synthesized by a hypothetical pathway. This review demonstrates an active and expansive lysine industry, and these green biomanufacturing strategies could also be applied to enhance the competitiveness of other amino acid industry.


Assuntos
Aminoácidos Neutros/biossíntese , Lisina/biossíntese , Aminoácidos/química , Ácido Aminocaproico/química , Materiais Biocompatíveis/química , Cadaverina/metabolismo , Caprolactama/química , Química Farmacêutica , Corynebacterium glutamicum/metabolismo , Escherichia coli/metabolismo , Fermentação , Química Verde , Microbiologia Industrial , Lactamas/química , Ácidos Pipecólicos/metabolismo , Piperidonas/química , Polímeros/química
14.
J Am Soc Nephrol ; 29(6): 1624-1635, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29610403

RESUMO

Background Reabsorption of amino acids (AAs) across the renal proximal tubule is crucial for intracellular and whole organism AA homeostasis. Although the luminal transport step is well understood, with several diseases caused by dysregulation of this process, the basolateral transport step is not understood. In humans, only cationic aminoaciduria due to malfunction of the basolateral transporter y+LAT1/CD98hc (SLC7A7/SLC3A2), which mediates the export of cationic AAs, has been described. Thus, the physiologic roles of basolateral transporters of neutral AAs, such as the antiporter LAT2/CD98hc (SLC7A8/SLC3A2), a heterodimer that exports most neutral AAs, and the uniporter TAT1 (SLC16A10), which exports only aromatic AAs, remain unclear. Functional cooperation between TAT1 and LAT2/CD98hc has been suggested by in vitro studies but has not been evaluated in vivoMethods To study the functional relationship of TAT1 and LAT2/CD98hc in vivo, we generated a double-knockout mouse model lacking TAT1 and LAT2, the catalytic subunit of LAT2/CD98hc (dKO LAT2-TAT1 mice).Results Compared with mice lacking only TAT1 or LAT2, dKO LAT2-TAT1 mice lost larger amounts of aromatic and other neutral AAs in their urine due to a tubular reabsorption defect. Notably, dKO mice also displayed decreased tubular reabsorption of cationic AAs and increased expression of y+LAT1/CD98hc.Conclusions The LAT2/CD98hc and TAT1 transporters functionally cooperate in vivo, and y+LAT1/CD98hc may compensate for the loss of LAT2/CD98hc and TAT1, functioning as a neutral AA exporter at the expense of some urinary loss of cationic AAs. Cooperative and compensatory mechanisms of AA transporters may explain the lack of basolateral neutral aminoacidurias in humans.


Assuntos
Sistema y+ de Transporte de Aminoácidos/genética , Sistemas de Transporte de Aminoácidos Neutros/genética , Aminoácidos Neutros/metabolismo , Cadeias Leves da Proteína-1 Reguladora de Fusão/genética , Reabsorção Renal , Sistema y+ de Transporte de Aminoácidos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Aminoácidos Neutros/urina , Animais , Feminino , Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Cadeias Leves da Proteína-1 Reguladora de Fusão/metabolismo , Túbulos Renais/fisiologia , Masculino , Camundongos Knockout
15.
Gen Comp Endocrinol ; 260: 146-150, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29339185

RESUMO

Tryptophan (Trp) has been associated with the regulation of several behavioral and physiological processes, through stimulation of serotonergic activity. Tryptophan utilization at the metabolic level is influenced by the competitive carrier system it shares with large neutral amino acids (LNAA). This study was carried out using meat-type chicken as a model, to investigate the dose response effects of Trp/LNAA on fear response (tonic immobility; TI) and hormonal responses, including corticosterone (CORT), serotonin (5-HT), triiodothyronine (T3) and thyroxine (T4). A total of 12 cages (48 birds) were assigned to each of the six experimental groups at 29-42 days of age. Experimental diets were formulated to have incremental levels of Trp/LNAA (0.025, 0.030, 0.035, 0.040, 0.045, and 0.050). The results revealed that, Trp/NAA had no significant effect on growth performance and TI of the birds. However, elevation of Trp/LNAA was concurred with a linear reduction in CORT (P < .0001, r2 = 0.819) and linear increases in 5-HT (P < .0001, r2 = 0.945), T3 (P = .0003, r2 = 0.403) and T4 (P < .0001, r2 = 0.937) levels. In conclusion, the results from the current study demonstrated that, although incremental levels of Trp/LNAA did not affect bird growth performance or fearfulness, it increased 5-HT, T3 and T4, and decreased CORT levels in a linear dose-dependent manner. Manipulation of Trp feeding levels could be applied to manage stressful conditions in birds.


Assuntos
Aminoácidos Neutros/farmacologia , Galinhas/fisiologia , Dieta , Medo/efeitos dos fármacos , Triptofano/farmacologia , Aminoácidos Neutros/química , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Galinhas/metabolismo , Corticosterona/sangue , Relação Dose-Resposta a Droga , Masculino , Modelos Animais , Serotonina/metabolismo
16.
J Nutr Biochem ; 53: 20-27, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29175141

RESUMO

Phenylketonuria treatment mainly consists of a phenylalanine-restricted diet but still results in suboptimal neuropsychological outcome, which is at least partly based on cerebral monoamine deficiencies, while, after childhood, treatment compliance decreases. Supplementation of large neutral amino acids (LNAAs) was previously demonstrated in young phenylketonuria mice to target all three biochemical disturbances underlying brain dysfunction in phenylketonuria. However, both its potential in adult phenylketonuria and the comparison with the phenylalanine-restricted diet remain to be established. To this purpose, several LNAA supplements were compared with a severe phenylalanine-restricted diet with respect to brain monoamine and amino acid concentrations in adult C57Bl/6 Pah-enu2 mice. Adult phenylketonuria mice received a phenylalanine-restricted diet, unrestricted diet supplemented with several combinations of LNAAs or AIN-93M control diet for 6 weeks. In addition, adult wild-type mice on AIN-93M diet served as controls. The severe phenylalanine-restricted diet in adult phenylketonuria mice significantly reduced plasma and brain phenylalanine and restored brain monoamine concentrations, while brain concentrations of most nonphenylalanine LNAAs remained subnormal. Supplementation of eight LNAAs was similarly effective as the severe phenylalanine-restricted diet to restore brain monoamines, while brain and plasma phenylalanine concentrations remained markedly elevated. These results provide biochemical support for the effectiveness of the severe phenylalanine-restricted diet and showed the possibilities of LNAA supplementation being equally effective to restore brain monoamines in adult phenylketonuria mice. Therefore, LNAA supplementation is a promising alternative treatment to phenylalanine restriction in adult phenylketonuria patients to further optimize neuropsychological functioning.


Assuntos
Aminoácidos Neutros/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Fenilcetonúrias/dietoterapia , Aminoácidos Neutros/sangue , Aminoácidos Neutros/metabolismo , Animais , Monoaminas Biogênicas/metabolismo , Suplementos Nutricionais , Modelos Animais de Doenças , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fenilalanina , Fenilcetonúrias/metabolismo
17.
Clin Physiol Funct Imaging ; 38(4): 656-662, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28795486

RESUMO

We reassessed data from a previous study on the transcerebral net exchange of large neutral amino acids (LNAAs) using a novel mathematical model of blood-brain barrier (BBB) transport. The study included twelve healthy volunteers who received a 4-h intravenous lipopolysaccharide (LPS) infusion (total dose: 0·3 ng/kg), a human experimental model of the systemic inflammatory response during the early stages of sepsis. Cerebral blood flow and arterial-to-jugular venous LNAA concentrations were measured prior to and after LPS, and the BBB transport and brain extracellular concentrations of LNAAs were calculated. The arterial concentration and unidirectional cerebral influx of phenylalanine increased after LPS. The BBB transport of tyrosine was unaffected, while its concentration in the brain extracellular fluid increased. These findings suggest that LPS infusion leads to an increased cerebral uptake of phenylalanine, which is then metabolized to tyrosine. This may reflect a neuroprotective mechanism that 'detoxifies' excess intracerebral phenylalanine in the clinical setting of sepsis.


Assuntos
Aminoácidos Neutros/sangue , Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar , Inflamação/sangue , Sepse/sangue , Adulto , Velocidade do Fluxo Sanguíneo , Barreira Hematoencefálica/fisiopatologia , Circulação Cerebrovascular , Humanos , Inflamação/induzido quimicamente , Inflamação/fisiopatologia , Infusões Intravenosas , Lipopolissacarídeos/administração & dosagem , Masculino , Modelos Biológicos , Fenilalanina/sangue , Sepse/induzido quimicamente , Sepse/fisiopatologia , Tirosina/sangue , Adulto Jovem
18.
Langmuir ; 33(50): 14451-14459, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29178796

RESUMO

Nanopore probing of biological polymers has the potential to achieve single-molecule sequencing at low cost, high throughput, portability, and minimal sample preparation and apparatus. In this article, we explore the possibility of discrimination between neutral amino acid residues from the primary structure of 30 amino acids long, engineered peptides, through the analysis of single-molecule ionic current fluctuations accompanying their slowed-down translocation across the wild type α-hemolysin (α-HL) nanopore, and molecular dynamics simulations. We found that the transient presence inside the α-HL of alanine or tryptophan residues from the primary sequence of engineered peptides results in distinct features of the ionic current fluctuation pattern associated with the peptide reversibly blocking the nanopore. We propose that α-HL sensitivity to the molecular exclusion at the most constricted region mediates ionic current blockade events correlated with the volumes that are occluded by at least three alanine or tryptophan residues, and provides the specificity needed to discriminate between groups of neutral amino acids. Further, we find that the pattern of current fluctuations depends on the orientation of the threaded amino acid residues, suggestive of a conformational anisotropy of the ensemble of conformations of the peptide on the restricted nanopore region, related to its relative axial orientation inside the nanopore.


Assuntos
Nanoporos , Aminoácidos Neutros , Proteínas Hemolisinas , Simulação de Dinâmica Molecular , Peptídeos
19.
PLoS One ; 12(9): e0185342, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28949985

RESUMO

INTRODUCTION: Hereditary Tyrosinemia type 1 (HT1) is a rare metabolic disease caused by a defect in the tyrosine degradation pathway. Current treatment consists of 2-(2-nitro-4-trifluoromethylbenoyl)-1,3-cyclohexanedione (NTBC) and a tyrosine and phenylalanine restricted diet. Recently, neuropsychological deficits have been seen in HT1 patients. These deficits are possibly associated with low blood phenylalanine concentrations and/or high blood tyrosine concentrations. Therefore, the aim of the present study was threefold. Firstly, we aimed to calculate how the plasma amino acid profile in HT1 patients may influence the presumptive brain influx of all large neutral amino acids (LNAA). Secondly, we aimed to investigate the effect of phenylalanine supplementation on presumptive brain phenylalanine and tyrosine influx. Thirdly, we aimed to theoretically determine minimal target plasma phenylalanine concentrations in HT1 patient to ensure adequate presumptive brain phenylalanine influx. METHODS: Data of plasma LNAA concentrations were obtained. In total, 239 samples of 9 HT1 children, treated with NTBC, diet, and partly with phenylalanine supplementation were collected together with 596 samples of independent control children. Presumptive brain influx of all LNAA was calculated, using Michaelis-Menten parameters (Km) and Vmax-values obtained from earlier articles. RESULTS: In HT1 patients, plasma concentrations and presumptive brain influx of tyrosine were higher. However, plasma and especially brain influx of phenylalanine were lower in HT1 patients. Phenylalanine supplementation did not only tend to increase plasma phenylalanine concentrations, but also presumptive brain phenylalanine influx, despite increased plasma tyrosine concentrations. However, to ensure sufficient brain phenylalanine influx in HT1 patients, minimal plasma phenylalanine concentrations may need to be higher than considered thus far. CONCLUSION: This study clearly suggests a role for disturbed brain LNAA biochemistry, which is not well reflected by plasma LNAA concentrations. This could play a role in the pathophysiology of the neuropsychological impairments in HT1 patients and may have therapeutic implications.


Assuntos
Aminoácidos Neutros/metabolismo , Encéfalo/metabolismo , Fenilalanina/administração & dosagem , Tirosinemias/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido
20.
Bioresour Technol ; 245(Pt B): 1692-1700, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28579174

RESUMO

This study examined nine expired industrial Corynebacterium glutamicum strains with high lysine producing capability for enhanced production of 5-AVA. C. glutamicum KCTC 1857 exhibiting the highest lysine production was transformed with either original Pseudomonas putida davBA genes, encoding the 5-AVA biosynthesis pathway, or C. glutamicum codon-optimized davBA genes. C. glutamicum KCTC 1857 expressing the original genes had superior cell viability and 5-AVA production capability compared to the other strain. This strain produced 39.93g/L of 5-AVA, which is the highest titer reported to date in fed-batch fermentation from glucose. Indeed, Miscanthus hydrolysate solution prepared from a novel process, comprising pretreatment, hydrolysis, purification, and concentration, was used as feedstock for 5-AVA production. A total of 12.51g/L 5-AVA was produced from the Miscanthus hydrolysate; this value is 34.7% higher than that obtained from glucose in batch fermentation.


Assuntos
Aminoácidos Neutros , Corynebacterium glutamicum , Fermentação , Hidrólise , Engenharia Metabólica
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