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1.
Biomed Res Int ; 2021: 9916328, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34541001

RESUMO

Ferroptosis and inflammation induced by cerebral hemorrhage result in an excessive inflammatory response and irreversible neuronal injury. Alleviating ferroptosis might be an effective way to prevent neuroinflammatory injury and promote neural functional recovery. Pyridoxal isonicotinoyl hydrazine (PIH), a lipophilic iron-chelating agent, has been reported to reduce excess iron-induced cytotoxicity. However, whether PIH could ameliorate the effects of hemorrhagic stroke is not completely understood. In the present study, the preventive effects of PIH in an intracerebral hemorrhage (ICH) mouse model were investigated. Neurological score, rotarod test, and immunofluorescence around the hematoma were assessed to evaluate the effects of PIH on hemorrhagic injury. The involvement of ferroptosis and inflammation was also examined in vitro to explore the underlying mechanism. Results showed that administration of PIH prevented neuronal cell death and reduced lipid peroxidation in Erastin-treated PC-12 cells. In vivo, mice treated with PIH after ICH attenuated neurological deficit scores. Additionally, we found PIH reduced ROS production, iron accumulation, and lipid peroxidation around the hematoma peripheral tissue. Meanwhile, ICH mice treated with PIH showed an upregulation of the key ferroptosis enzyme, glutathione peroxidase 4, and downregulation of cyclooxygenase-2. Moreover, PIH administration inhibited proinflammatory polarization and reduced interleukin-1 beta and tumor necrosis factor alpha in ICH mice. Collectively, these results demonstrated that PIH protects mice against hemorrhage stroke, which was associated with mitigation of inflammation and ferroptosis.


Assuntos
Hemorragia Cerebral/tratamento farmacológico , Ferroptose/efeitos dos fármacos , Isoniazida/análogos & derivados , Piridoxal/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Hemorragia Cerebral/metabolismo , Compostos Férricos/farmacologia , Ferroptose/fisiologia , Inflamação/tratamento farmacológico , Inflamação/prevenção & controle , Ferro/metabolismo , Quelantes de Ferro/farmacologia , Isoniazida/metabolismo , Isoniazida/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Piridoxal/metabolismo , Piridoxal/farmacologia
2.
Talanta ; 234: 122661, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364469

RESUMO

Racemic α-amino acid standards for chiral metabolomics were prepared from l-α-amino acids using a hydrophobic pyridoxal derivative, namely 3-hydroxy-2-methyl-5-((octyloxy)methyl)isonicotinaldehyde (OPy), as the racemization catalyst. Among the 19 tested proteinogenic amino acids, 13 (including the generally unstable asparagine, glutamine, and tryptophan) underwent efficient racemization/epimerization under mildly basic conditions at room temperature, while solid-phase extraction allowed for effective and simple catalyst removal and amino acid recovery, obviating the need for chromatographic separation and recrystallization. Isotopically labeled racemic amino acids are commonly employed as internal standards for highly accurate mass spectrometric analysis. However, as isotopically labeled d-amino acids are often unavailable or highly expensive, the developed method was used to prepare racemic labeled amino acids, which were shown to enhance the repeatability and accuracy of d,l-amino acid quantitation in human urine by liquid chromatography-mass spectrometry (LC-MS). Given that our method should also be applicable to non-proteinogenic α-amino acids and the N-termini of peptides, the present study is expected to accelerate the development of LC-MS-based chiral metabolomics.


Assuntos
Aminoácidos , Piridoxal , Catálise , Cromatografia Líquida , Humanos , Espectrometria de Massas
3.
Bone ; 150: 116007, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34000433

RESUMO

Pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6), is elevated in the plasma of individuals with hypophosphatasia (HPP). HPP is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of ALPL, the gene that encodes the "tissue-nonspecific" isoenzyme of alkaline phosphatase (TNSALP). PLP accumulates extracellularly in HPP because it is a natural substrate of this cell-surface phosphomonoester phosphohydrolase. Even individuals mildly affected by HPP manifest this biochemical hallmark, which is used for diagnosis. Herein, an exclusively breast-fed newborn boy with life-threatening perinatal HPP had uniquely normal instead of markedly elevated plasma PLP levels before beginning asfotase alfa (AA) TNSALP-replacement therapy. These abnormal PLP levels were explained by B6 deficiency, confirmed by his low plasma level of 4-pyridoxic acid (PA), the B6 degradation product. His mother, a presumed carrier of one of his two ALPL missense mutations, had serum ALP activity of 50 U/L (Nl 40-130) while her plasma PLP level was 9 µg/L (Nl 5-50) and PA was 3 µg/L (Nl 3-30). Her dietary history and breast milk pyridoxal (PL) level indicated she too was B6 deficient. With B6 supplementation using a breast milk fortifier, the patient's plasma PA level corrected, while his PLP level remained in the normal range but now in keeping with AA treatment. Our experience reveals that elevated levels of PLP in the circulation in HPP require some degree of B6 sufficiency, and that anticipated increases in HPP can be negated by hypovitaminosis B6.


Assuntos
Hipofosfatasia , Fosfatase Alcalina , Feminino , Humanos , Hipofosfatasia/tratamento farmacológico , Hipofosfatasia/genética , Recém-Nascido , Masculino , Fosfatos , Gravidez , Piridoxal , Vitamina B 6 , Vitaminas
4.
J Org Chem ; 86(9): 6592-6599, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33830765

RESUMO

Density functional theory calculations have been performed to gain insights into the catalytic mechanism of the N-quaternized pyridoxal (i.e., 1a)-mediated biomimetic asymmetric Mannich reaction of tert-butyl glycinate 3 with N-diphenylphosphinyl imine 2a to give the diamino acid ester 4a in high yield with excellent enantiomeric and diastereomeric selectivity (Science 2018, 360, 1438). The study reveals that the whole catalysis can be characterized via three stages: (i) the catalyst 1a reacts with the tert-butyl glycinate 3 to generate the active carbanion complex IM3. (ii) IM3 then reacts with the N-diphenylphosphinyl imine 2a giving the imine intermediate IM8. (iii) IM8 undergoes hydrolysis to give the final product anti-4a and regenerate the catalyst 1a for the next catalytic cycle. Each stage is kinetically and thermodynamically feasible for experimental realization. The hydrolysis step in the stage III is predicted to be the rate-determining step during the whole catalytic cycle. Furthermore, the origins of the enantioselectivity and diastereoselectivity for the target reaction, as well as the deactivation of the catalyst 1b, are also discussed.


Assuntos
Biomimética , Piridoxal , Catálise , Iminas , Estereoisomerismo
5.
ChemSusChem ; 14(8): 1781-1804, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33631048

RESUMO

In recent years, (de)carboxylases that catalyze reversible (de)carboxylation have been targeted for application as carboxylation catalysts. This has led to the development of proof-of-concept (bio)synthetic CO2 fixation routes for chemical production. However, further progress towards industrial application has been hampered by the thermodynamic constraint that accompanies fixing CO2 to organic molecules. In this Review, biocatalytic carboxylation methods are discussed with emphases on the diverse strategies devised to alleviate the inherent thermodynamic constraints and their application in synthetic CO2 -fixation cascades.


Assuntos
Dióxido de Carbono/química , Carboxiliases/química , Carboxiliases/metabolismo , Biocatálise , Biotina/química , Dinitrocresóis/química , Metais/química , Estrutura Molecular , Piridoxal/química , Relação Estrutura-Atividade , Termodinâmica , Tiamina Pirofosfato/química
6.
J Inorg Biochem ; 215: 111307, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33341589

RESUMO

This article deals with the synthesis of Schiff-based bis-azomethine-based ligands derived from pyridoxal and aliphatic dihydrazides and the synthesis of nickel(II) complexes C1-C4. The synthesized complexes had their structures elucidated by monocrystal X-ray diffraction and were characterized by vibrational and absorption spectroscopy. The synthesized ligands have characteristics that allow the formation of self-assembly processes, thus, the flexibility or rigidity of the coordination of organic molecules added to the orbitals of the NiII cation leads to the formation of helical complexes with double helix and a dinucler nickel(II) complex. Moreover, compounds was their interactions with CT-DNA and HSA absorption and emission analysis and molecular docking calculations.


Assuntos
Complexos de Coordenação/química , Níquel/química , Piridoxal/química , Adipatos/química , Compostos Azo/química , Cristalografia por Raios X/métodos , DNA/química , Humanos , Hidrazinas/química , Ligantes , Simulação de Acoplamento Molecular/métodos , Estrutura Molecular , Bases de Schiff/química , Albumina Sérica Humana/química , Solubilidade , Succinatos/química , Tiossemicarbazonas/química , Água/química , Difração de Raios X/métodos
7.
Neuro Oncol ; 23(2): 277-283, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32644145

RESUMO

BACKGROUND: There is evidence for an inherited contribution to primary brain cancer. Linkage analysis of high-risk brain cancer pedigrees has identified candidate regions of interest in which brain cancer predisposition genes are likely to reside. METHODS: Genome-wide linkage analysis was performed in a unique set of 11 informative, extended, high-risk primary brain cancer pedigrees identified in a population genealogy database, which include from 2 to 6 sampled, related primary brain cancer cases. Access to formalin-fixed paraffin embedded tissue samples archived in a biorepository allowed analysis of extended pedigrees. RESULTS: Individual high-risk pedigrees were singly informative for linkage at multiple regions. Suggestive evidence for linkage was observed on chromosomes 2, 3, 14, and 16. The chromosome 16 region in particular contains a promising candidate gene, pyridoxal-dependent decarboxylase domain-containing 1 (PDXDC1), with prior evidence for involvement with glioblastoma from other previously reported experimental settings, and contains the lead single nucleotide polymorphism (rs3198697) from the linkage analysis of the chromosome 16 region. CONCLUSIONS: Pedigrees with a statistical excess of primary brain cancers have been identified in a unique genealogy resource representing the homogeneous Utah population. Genome-wide linkage analysis of these pedigrees has identified a potential candidate predisposition gene, as well as multiple candidate regions that could harbor predisposition loci, and for which further analysis is suggested.


Assuntos
Neoplasias Encefálicas , Piridoxal , Neoplasias Encefálicas/genética , Predisposição Genética para Doença , Humanos , Linhagem , Utah
8.
Pediatr Neurol ; 113: 33-41, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32980745

RESUMO

BACKGROUND: We aimed to demonstrate the biochemical characteristics of vitamin B6-dependent epilepsy, with a particular focus on pyridoxal 5'-phosphate and pyridoxal in the cerebrospinal fluid. METHODS: Using our laboratory database, we identified patients with vitamin B6-dependent epilepsy and extracted their data on the concentrations of pyridoxal 5'-phosphate, pyridoxal, pipecolic acid, α-aminoadipic semialdehyde, and monoamine neurotransmitters. We compared the biochemical characteristics of these patients with those of other epilepsy patients with low pyridoxal 5'-phosphate concentrations. RESULTS: We identified seven patients with pyridoxine-dependent epilepsy caused by an ALDH7A1 gene abnormality, two patients with pyridoxal 5'-phosphate homeostasis protein deficiency, and 28 patients with other epilepsies with low cerebrospinal fluid pyridoxal 5'-phosphate concentrations. Cerebrospinal fluid pyridoxal and pyridoxal 5'-phosphate concentrations were low in patients with vitamin B6-dependent epilepsy but cerebrospinal fluid pyridoxal concentrations were not reduced in most patients with other epilepsies with low cerebrospinal fluid pyridoxal 5'-phosphate concentrations. Increase in 3-O-methyldopa and 5-hydroxytryptophan was demonstrated in some patients with vitamin B6-dependent epilepsy, suggestive of pyridoxal 5'-phosphate deficiency in the brain. CONCLUSIONS: Low cerebrospinal fluid pyridoxal concentrations may be a better indicator of pyridoxal 5'-phosphate deficiency in the brain in vitamin B6-dependent epilepsy than low cerebrospinal fluid pyridoxal 5'-phosphate concentrations. This finding is especially helpful in individuals with suspected pyridoxal 5'-phosphate homeostasis protein deficiency, which does not have known biomarkers.


Assuntos
Epilepsia/metabolismo , Fosfato de Piridoxal/líquido cefalorraquidiano , Piridoxal/líquido cefalorraquidiano , 5-Hidroxitriptofano/metabolismo , Adolescente , Criança , Pré-Escolar , Epilepsia/diagnóstico , Epilepsia/etiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Ácidos Pipecólicos/metabolismo , Estudos Retrospectivos , Tirosina/análogos & derivados , Tirosina/metabolismo , Vitamina B 6 , Adulto Jovem
9.
Photochem Photobiol Sci ; 19(10): 1402-1409, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32914816

RESUMO

Aggregation-induced emission (AIE) properties of an easy-to-prepare and structurally planar Schiff base derivative of the vitamin B6 cofactor pyridoxal (L) were investigated in DMSO-H2O mixed solvents. Compound L showed weak fluorescence (λem = 425 nm) in pure DMSO, but increasing the fraction of water in DMSO resulted in a significant fluorescence enhancement at 575 nm due to the restriction of intramolecular rotation (RIR) of L upon aggregation. SEM analyses revealed the formation of hairy micelle-like or needle-shaped self-assemblies/aggregates of L. The DFT calculations were performed to examine the tendency of L to form self-aggregates, and the results indicate the formation of several intramolecular non-covalent interactions that energetically favored the self-aggregation of L. The pH sensing study revealed that the red-emission of aggregates of L between pH 5.9 and 9.0 turned into green emission at the basic pH with the estimated pKa values of 9.39 and 10.22. Further, the aggregates of L were applied for the visualization of latent fingerprints (LFPs) over a non-porous glass slide.


Assuntos
Piridoxal/química , Vitamina B 6/química , Teoria da Densidade Funcional , Dimetil Sulfóxido/química , Concentração de Íons de Hidrogênio , Estrutura Molecular , Tamanho da Partícula , Bases de Schiff/química , Propriedades de Superfície , Água/química
10.
Molecules ; 25(17)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872122

RESUMO

Water-soluble vitamins like B3 (nicotinamide), B6 (pyridoxine), and B9 (folic acid) are of utmost importance in human health and disease, as they are involved in numerous critical metabolic reactions. Not surprisingly, deficiencies of these vitamins have been linked to various disease states. Unfortunately, not much is known about the physiological levels of B6 vitamers and vitamin B3 in an ethnically isolated group (such as an Emirati population), as well as their relationship with obesity. The aim of the present study was to quantify various B6 vitamers, as well as B3, in the plasma of obese and healthy Emirati populations and to examine their correlation with obesity. A sensitive and robust HPLC-MS/MS-based method was developed for the simultaneous quantitation of five physiologically relevant forms of vitamin B6, namely pyridoxal, pyridoxine, pyridoxamine, pyridoxamine phosphate, and pyridoxal phosphate, as well as nicotinamide, in human plasma. This method was used to quantify the concentrations of these vitamers in the plasma of 57 healthy and 57 obese Emirati volunteers. Our analysis showed that the plasma concentrations of nicotinamide, pyridoxal, and pyridoxamine phosphate in the obese Emirati population were significantly higher than those in healthy volunteers (p < 0.0001, p = 0.0006, and p = 0.002, respectively). No significant differences were observed for the plasma concentrations of pyridoxine and pyridoxal phosphate. Furthermore, the concentrations of some of these vitamers in healthy Emirati volunteers were significantly different than those published in the literature for Western populations, such as American and European volunteers. This initial study underscores the need to quantify micronutrients in distinct ethnic groups, as well as people suffering from chronic metabolic disorders.


Assuntos
Biomarcadores , Niacinamida/sangue , Obesidade/sangue , Obesidade/epidemiologia , Piridoxal/sangue , Piridoxamina/análogos & derivados , Adolescente , Adulto , Cromatografia Líquida , Estudos Transversais , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Vigilância em Saúde Pública , Piridoxamina/sangue , Sensibilidade e Especificidade , Adulto Jovem
11.
Toxicol Appl Pharmacol ; 402: 115134, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32673658

RESUMO

Isoniazid (INH)-induced liver injury may be associated with inhibition of the liver farnesoid X receptor (FXR). However, the relationship between FXR and INH-induced liver injury remained unclear. The present study was performed to clarify the role of inhibition of FXR in the pathogenesis of INH-induced liver injury and to further identify potential inhibitors of FXR from INH and its metabolites. HepaRG cells were treated with INH (10 mM) plus mixed bile acids (BA) and rats were treated with INH (60-600 mg/kg p.o.) or INH plus obeticholic acid (OCA, 10 mg/kg), a potent FXR agonist, for seven days. INH can cause BA-dependent toxicity and apoptosis with elevated intracellular bile acids in vitro; indeed, in these studies, liver bile acids and mRNA levels for Cyp7a1, an FXR target gene were increased, while mRNA levels for FXR and Shp were significantly decreased, and these changes could be prevented by co-treatment with the FXR agonist OCA. In silico molecular docking studies showed that INH, acetyl isoniazid, isonicotinic acid and PIH may be potential FXR inhibitors, and a TR-FRET FXR-coactivator assay confirmed that PIH is a strong antagonist of FXR (IC50 = 52 nM). To further determine if PIH also inhibits FXR activity in vivo, rats were treated with PIH directly (5 mg/kg). Liver total bile acids were significantly increased while FXR expression was not changed, but Shp mRNA levels were significantly decreased and Cyp7a1 mRNA was significantly increased, consistent with PIH acting as an FXR antagonist. In summary, PIH inhibition of liver FXR function leading to bile acid accumulation in hepatocytes may be an early pathogenesis event in INH-induced liver injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Hepatócitos/efeitos dos fármacos , Isoniazida/análogos & derivados , Isoniazida/farmacologia , Piridoxal/análogos & derivados , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Apoptose/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Ácidos e Sais Biliares/metabolismo , Fígado Gorduroso/induzido quimicamente , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Isoniazida/metabolismo , Masculino , Modelos Moleculares , Necrose/induzido quimicamente , Conformação Proteica , Piridoxal/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
12.
Am J Clin Nutr ; 112(3): 669-682, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32649760

RESUMO

BACKGROUND: Maternal supplementation during lactation could increase milk B-vitamin concentrations, but little is known about the kinetics of milk vitamin responses. OBJECTIVES: We compared acute effects of maternal lipid-based nutrient supplement (LNS) consumption (n = 22 nutrients, 175%-212% of the RDA intake for the nutrients examined), as a single dose or at spaced intervals during 8 h, on milk concentrations and infant intake from milk of B-vitamins. METHODS: This randomized crossover trial in Quetzaltenango, Guatemala included 26 mother-infant dyads 4-6 mo postpartum who were randomly assigned to receive 3 treatments in a random order: bolus 30-g dose of LNS (Bolus); 3 × 10-g doses of LNS (Divided); and no LNS (Control), with control meals. Mothers attended three 8-h visits during which infant milk consumption was measured and milk samples were collected at every feed. Infant intake was assessed as $\mathop \sum \nolimits_{i\ = \ 1}^n ( {{\rm{milk\ volum}}{{\rm{e}}_{{\rm{feed\ }}n}} \times \ {\rm{nutrient\ concentratio}}{{\rm{n}}_{{\rm{feed}}\ n}}} )$ over 8 h. RESULTS: Maternal supplementation with the Bolus or Divided dose increased least-squares mean (95% CI) milk and infant intakes of riboflavin [milk: Bolus: 154.4 (138.2, 172.5) µg · min-1 · mL-1; Control: 84.5 (75.8, 94.3) µg · min-1 · mL-1; infant: Bolus: 64.5 (56.1, 74.3) µg; Control: 34.5 (30.0, 39.6) µg], thiamin [milk: Bolus: 10.9 (10.1, 11.7) µg · min-1 · mL-1; Control: 7.7 (7.2, 8.3) µg · min-1 · mL-1; infant: Bolus: 5.1 (4.4, 6.0) µg; Control: 3.4 (2.9, 4.0) µg], and pyridoxal [milk: Bolus: 90.5 (82.8, 98.9) µg · min-1 · mL-1; Control: 60.8 (55.8, 66.3) µg · min-1 · mL-1; infant: Bolus: 39.4 (33.5, 46.4) µg; Control: 25.0 (21.4, 29.2) µg] (all P < 0.001). Only the Bolus dose increased cobalamin in milk [Bolus: 0.054 (0.047, 0.061) µg · min-1 · mL-1; Control: 0.041 (0.035, 0.048) µg · min-1 · mL-1, P = 0.039] and infant cobalamin intake [Bolus: 0.023 (0.020, 0.027) µg; Control: 0.015 (0.013, 0.018) µg, P = 0.001] compared with Control. Niacin was unaffected. CONCLUSIONS: Maternal supplementation with LNS as a Bolus or Divided dose was similarly effective at increasing milk riboflavin, thiamin, and pyridoxal and infant intakes, whereas only the Bolus dose increased cobalamin. Niacin was unaffected in 8 h. This trial was registered at clinicaltrials.gov as NCT02464111.


Assuntos
Aleitamento Materno , Lactação , Micronutrientes/administração & dosagem , Micronutrientes/sangue , Vitaminas/administração & dosagem , Vitaminas/sangue , Adulto , Área Sob a Curva , Estudos Cross-Over , Suplementos Nutricionais , Feminino , Guatemala , Humanos , Lactente , Micronutrientes/química , Leite Humano/química , Niacina/administração & dosagem , Niacina/sangue , Niacina/farmacocinética , Piridoxal/administração & dosagem , Piridoxal/sangue , Piridoxal/farmacocinética , Riboflavina/administração & dosagem , Riboflavina/sangue , Riboflavina/farmacocinética , Tiamina/administração & dosagem , Tiamina/sangue , Tiamina/farmacocinética , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Vitamina B 12/farmacocinética , Vitaminas/farmacocinética , Adulto Jovem
13.
Chem Commun (Camb) ; 56(55): 7601-7604, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32514510

RESUMO

Two types of pyridoxal analogs, azido pyridoxal (PL-N3) and carboxyl pyridoxal (PL-COOH), were developed as novel bifunctional bioorthogonal molecules. These molecules showed fast imine formation with hydrazinyl groups and stable covalent linkages via azido/carboxyl groups, and thus were of great use for site-specific peptide and protein modifications.


Assuntos
Proteínas de Fluorescência Verde/química , Indicadores e Reagentes/química , Peptídeos/química , Piridoxal/análogos & derivados , Soroalbumina Bovina/química , Animais , Bovinos , Indicadores e Reagentes/síntese química , Piridoxal/síntese química
14.
J Bacteriol ; 202(12)2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32253339

RESUMO

Pyridoxal 5'-phosphate (PLP) is the biologically active form of vitamin B6 and an essential cofactor in all organisms. In Escherichia coli, PLP is synthesized via the deoxyxylulose 5-phosphate (DXP)-dependent pathway that includes seven enzymatic steps and generates pyridoxine 5'-phosphate as an intermediate. Additionally, E. coli is able to salvage pyridoxal, pyridoxine, and pyridoxamine B6 vitamers to produce PLP using kinases PdxK/PdxY and pyridox(am)ine phosphate oxidase (PdxH). We found that E. coli strains blocked in PLP synthesis prior to the formation of pyridoxine 5'-phosphate (PNP) required significantly less exogenous pyridoxal (PL) than strains lacking pdxH and identified the conversion of PL to pyridoxine (PN) during cultivation to be the cause. Our data showed that PdxI, shown to have PL reductase activity in vitro, was required for the efficient salvage of PL in E. coli The pdxI+ E. coli strains converted exogenous PL to PN during growth, while pdxI mutants did not. In total, the data herein demonstrated that PdxI is a critical enzyme in the salvage of PL by E. coli IMPORTANCE The biosynthetic pathway of pyridoxal 5'-phosphate (PLP) has extensively been studied in Escherichia coli, yet limited information is available about the vitamin B6 salvage pathway. We show that the protein PdxI (YdbC) is the primary pyridoxal (PL) reductase in E. coli and is involved in the salvage of PL. The orthologs of PdxI occur in a wide range of bacteria and plants, suggesting that PL reductase in the B6 salvage pathway is more widely distributed than previously expected.


Assuntos
Escherichia coli/enzimologia , Oxirredutases/metabolismo , Piridoxal/biossíntese , Vias Biossintéticas , Escherichia coli/genética , Escherichia coli/metabolismo , Oxirredutases/genética , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/metabolismo
15.
Food Res Int ; 131: 108951, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32247447

RESUMO

Proteomic analysis of foodborne pathogen Listeria monocytogenes after treatment with three disinfectants based on ammonium salts of pyridoxal oxime (POD) reveal perturbation of cellular processes. These inhibitors caused disturbance in the synthesis of plasma membrane proteins and cell wall proteoglycans. Some of key proteins and proteoglycans from these two groups that are important for bacterial growth are down-regulated. Additionally, we demonstrated that the main bacterial toxin Listeriolysin O (LLO) is significantly down-regulated after treatment with each of three investigated inhibitors. These investigations confirm already postulated mechanism of action of POD-based inhibitors that results in disturbance of key cell surface proteins and proteoglycans in Gram-positive bacteria. Additionally, the use of some proteins such as LLO, as potential biomarker candidates of food poisoning with this bacterium is discussed.


Assuntos
Toxinas Bacterianas/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Proteínas Hemolisinas/metabolismo , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/metabolismo , Piridoxal/análogos & derivados , Toxinas Bacterianas/genética , Cromatografia Líquida , Regulação para Baixo , Proteínas de Choque Térmico/genética , Proteínas Hemolisinas/genética , Proteômica , Piridoxal/farmacologia , Espectrometria de Massas em Tandem/métodos
16.
17.
Brain Dev ; 42(5): 402-407, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32107100

RESUMO

BACKGROUND: The initial presentation of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is indistinguishable from that of complex febrile seizures (FS), which poses a great diagnostic challenge for clinicians. Excitotoxicity is speculated to be the pathogenesis of AESD. Vitamin B6 (VB6) is essential for the biosynthesis of gamma-aminobutyric acid, an inhibitory neurotransmitter. The aim of this study is to investigate our hypothesis that VB6 deficiency in the brain may play a role in AESD. METHODS: We obtained cerebrospinal fluid (CSF) samples from pediatric patients with AESD after early seizures and those with FS. We measured pyridoxal 5'-phosphate (PLP) and pyridoxal (PL) concentrations in the CSF samples using high-performance liquid chromatography with fluorescence detection. RESULTS: The subjects were 5 patients with AESD and 17 patients with FS. Age did not differ significantly between AESD and FS. In AESD, CSF PLP concentration was marginally lower (p = 0.0999) and the PLP-to-PL ratio was significantly (p = 0.0417) reduced compared to those in FS. CONCLUSIONS: Although it is impossible to conclude that low PLP concentration and PLP-to-PL ratio are causative of AESD, this may be a risk factor for developing AESD. When combined with other markers, this finding may be useful in distinguishing AESD from FS upon initial presentation.


Assuntos
Encefalopatias/líquido cefalorraquidiano , Fosfato de Piridoxal/líquido cefalorraquidiano , Piridoxal/líquido cefalorraquidiano , Convulsões/líquido cefalorraquidiano , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Vitamina B 6/líquido cefalorraquidiano
18.
Med Mycol ; 58(7): 919-927, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31915818

RESUMO

Previously we found that three components of a commonly used mammalian cell culture medium incorporated into agar killed cryptococci (Granger and Call 2019). The components were L-cystine, iron [Fe(III)], and pyridoxal (CIP). We now report on a buffered solution at neutral pH of the three components, which was highly fungicidal without agar. We showed that CIP fungicidal activity, identical to the findings with cell culture medium, was inactivated by visible light and was unstable with storage in the dark. Congeners replacing either pyridoxal or L-cystine in CIP revealed structural requirements for fungicidal activity. Replacing pyridoxal in CIP with 2-hydroxy-5-nitrobenzaldehyde produced a solution that was equally fungicidal and maintained fungicidal activity upon storage in the dark for up to 50 days. We employed methods for excluding iron from CIP and found that fungicidal activity was not affected. Upon mixing L-cystine and pyridoxal in buffer at pH 7.0, diode array spectroscopy revealed a red-shift of absorbance maximum from 391 nm to 398 nm. Our findings point to Schiff base reaction between the pyridoxal aldehyde group of C1 with the alpha amino group(s) of cystine to yield a fungicidal compound. Light at wave length approximately 400 nm inactivates this complex accompanied by bleaching of the pyridine ring of pyridoxal. Our findings may be useful for design of a class of fungicidal compounds formed through Schiff base reaction of disulfide compounds with aromatic ring-bearing aldehydes.


Assuntos
Criptococose/tratamento farmacológico , Cryptococcus neoformans/efeitos dos fármacos , Cistina/química , Fungicidas Industriais/química , Ferro/química , Micoses/tratamento farmacológico , Piridoxal/química , Humanos
19.
J Inorg Biochem ; 204: 110950, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31835108

RESUMO

This work presents the synthesis, characterization of copper(II) complexes (C1-C6) and the potential of these compounds to mimic the catalytic activity of the enzyme superoxide dismutase (SOD). The copper(II)complexes were obtained by reaction between the aldol condensation between substituted aromatic hydrazides and aromatic aldehydes (salicylic aldehyde and pyridoxal hydrochloride), forming two new ligands (L1 to L6), resulting in new dimeric dicopper (II) complexes (C1 and C2), new three monomeric CuII derivatives (C3, C4 and C6) and a polymeric complex (C5). The CuII complexes were fully characterized by X-ray diffraction, spectroscopic and electrochemical analysis. Subsequently, CuII derivatives were evaluated for their antioxidant activities, using the NBT (Nitro blue tetrazolium chloride) photoreduction methodology. After evaluating the antioxidant activity in vitro, it was observed that the best inhibition rates of the superoxide ion are associated to the C4 and C5 complexes. Computational analysis via molecular docking and quantum chemical calculation (Fukui map) offered a molecular level explanation on the biological activity of CuII complexes. Additionally, cytotoxicity of C1-C6 was tested in the first time in vivo in nematodes Caenorhabditis elegans, corroborating with the results identified for C4 and C5.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Cobre/química , Piridoxal/química , Superóxido Dismutase/metabolismo , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Complexos de Coordenação/química , Ligantes , Simulação de Acoplamento Molecular , Superóxidos/metabolismo
20.
Front Immunol ; 11: 622162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33613557

RESUMO

Schistosomes are parasitic platyhelminths that currently infect >200 million people globally. The adult worms can live within the vasculature of their hosts for many years where they acquire all nutrients necessary for their survival and growth. In this work we focus on how Schistosoma mansoni parasites acquire and metabolize vitamin B6, whose active form is pyridoxal phosphate (PLP). We show here that live intravascular stage parasites (schistosomula and adult males and females) can cleave exogenous PLP to liberate pyridoxal. Of the three characterized nucleotide-metabolizing ectoenzymes expressed at the schistosome surface (SmAP, SmNPP5, and SmATPDase1), only SmAP hydrolyzes PLP. Heat-inactivated recombinant SmAP can no longer cleave PLP. Further, parasites whose SmAP gene has been suppressed by RNAi are significantly impaired in their ability to cleave PLP compared to controls. When schistosomes are incubated in murine plasma, they alter its metabolomic profile-the levels of both pyridoxal and phosphate increase over time, a finding consistent with the action of host-exposed SmAP acting on PLP. We hypothesize that SmAP-mediated dephosphorylation of PLP generates a pool of pyridoxal around the worms that can be conveniently taken in by the parasites to participate in essential, vitamin B6-driven metabolism. In addition, since host PLP-dependent enzymes play active roles in inflammatory processes, parasite-mediated cleavage of this metabolite may serve to limit parasite-damaging inflammation. In this work we also identified schistosome homologs of enzymes that are involved in intracellular vitamin B6 metabolism. These are pyridoxal kinase (SmPK) as well as pyridoxal phosphate phosphatase (SmPLP-Ph) and pyridox(am)ine 5'-phosphate oxidase (SmPNPO) and cDNAs encoding these three enzymes were cloned and sequenced. The three genes encoding these enzymes all display high relative expression in schistosomula and adult worms suggestive of robust vitamin B6 metabolism in the intravascular life stages.


Assuntos
Fosfatase Alcalina/metabolismo , Fosfato de Piridoxal/sangue , Schistosoma mansoni/metabolismo , Vitamina B 6/metabolismo , Fosfatase Alcalina/genética , Sequência de Aminoácidos , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Masculino , Camundongos , Fosfatos/sangue , Monoéster Fosfórico Hidrolases/sangue , Monoéster Fosfórico Hidrolases/genética , Fosforilação , Filogenia , Piridoxal/sangue , Piridoxal Quinase/sangue , Piridoxal Quinase/genética , Fosfato de Piridoxal/metabolismo , Piridoxaminafosfato Oxidase/sangue , Piridoxaminafosfato Oxidase/genética , Interferência de RNA , Proteínas Recombinantes , Schistosoma mansoni/enzimologia , Schistosoma mansoni/genética , Schistosoma mansoni/crescimento & desenvolvimento , Alinhamento de Sequência
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