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1.
J Transl Med ; 22(1): 48, 2024 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-38216927

RESUMO

BACKGROUND: Muscle-invasive bladder cancer (MIBC) is a highly aggressive disease with a poor prognosis. B cells are crucial factors in tumor suppression, and tertiary lymphoid structures (TLSs) facilitate immune cell recruitment to the tumor microenvironment (TME). However, the function and mechanisms of tumor-infiltrating B cells and TLSs in MIBC need to be explored further. METHODS: We performed single-cell RNA sequencing analysis of 11,612 B cells and 55,392 T cells from 12 bladder cancer patients and found naïve B cells, proliferating B cells, plasma cells, interferon-stimulated B cells and germinal center-associated B cells, and described the phenotype, gene enrichment, cell-cell communication, biological processes. We utilized immunohistochemistry (IHC) and immunofluorescence (IF) to describe TLSs morphology in MIBC. RESULTS: The interferon-stimulated B-cell subtype (B-ISG15) and germinal center-associated B-cell subtypes (B-LMO2, B-STMN1) were significantly enriched in MIBC. TLSs in MIBC exhibited a distinct follicular structure characterized by a central region of B cells resembling a germinal center surrounded by T cells. CellChat analysis showed that CXCL13 + T cells play a pivotal role in recruiting CXCR5 + B cells. Cell migration experiments demonstrated the chemoattraction of CXCL13 toward CXCR5 + B cells. Importantly, the infiltration of the interferon-stimulated B-cell subtype and the presence of TLSs correlated with a more favorable prognosis in MIBC. CONCLUSIONS: The study revealed the heterogeneity of B-cell subtypes in MIBC and suggests a pivotal role of TLSs in MIBC outcomes. Our study provides novel insights that contribute to the precision treatment of MIBC.


Assuntos
Estruturas Linfoides Terciárias , Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Linfócitos B , Prognóstico , Músculos/patologia , Interferons , Microambiente Tumoral
2.
Metabolomics ; 20(3): 57, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773045

RESUMO

BACKGROUND: Despite the clear clinical diagnostic criteria for necrozoospermia in andrology, the fundamental mechanisms underlying it remain elusive. This study aims to profile the lipid composition in seminal plasma systematically and to ascertain the potential of lipid biomarkers in the accurate diagnosis of necrozoospermia. It also evaluates the efficacy of a lipidomics-based random forest algorithm model in identifying necrozoospermia. METHODS: Seminal plasma samples were collected from patients diagnosed with necrozoospermia (n = 28) and normozoospermia (n = 28). Liquid chromatography-mass spectrometry (LC-MS) was used to perform lipidomic analysis and identify the underlying biomarkers. A lipid functional enrichment analysis was conducted using the LION lipid ontology database. The top 100 differentially significant lipids were subjected to lipid biomarker examination through random forest machine learning model. RESULTS: Lipidomic analysis identified 46 lipid classes comprising 1267 lipid metabolites in seminal plasma. The top five enriched lipid functions as follows: fatty acid (FA) with ≤ 18 carbons, FA with 16-18 carbons, monounsaturated FA, FA with 18 carbons, and FA with 16 carbons. The top 100 differentially significant lipids were subjected to machine learning analysis and identified 20 feature lipids. The random forest model identified lipids with an area under the curve > 0.8, including LPE(20:4) and TG(4:0_14:1_16:0). CONCLUSIONS: LPE(20:4) and TG(4:0_14:1_16:0), were identified as differential lipids for necrozoospermia. Seminal plasma lipidomic analysis could provide valuable biochemical information for the diagnosis of necrozoospermia, and its combination with conventional sperm analysis may improve the accuracy and reliability of the diagnosis.


Assuntos
Algoritmos , Lipidômica , Sêmen , Masculino , Humanos , Sêmen/metabolismo , Sêmen/química , Lipidômica/métodos , Adulto , Lipídeos/análise , Lipídeos/sangue , Biomarcadores/sangue , Aprendizado de Máquina , Cromatografia Líquida/métodos , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/metabolismo , Espectrometria de Massas/métodos , Algoritmo Florestas Aleatórias
3.
World J Microbiol Biotechnol ; 39(12): 352, 2023 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-37864750

RESUMO

Formate dehydrogenase (FDH) is a D-2-hydroxy acid dehydrogenase, which can reversibly reduce CO2 to formate and thus act as non-photosynthetic CO2 reductase. In order to increase catalytic efficiency of formate dehydrogenase for CO2 reduction, two mutants V328I/F285W and V354G/F285W were obtained of which reduction activity was about two times more than the parent CbFDHM2, and the formate production from CO2 catalyzed by mutants were 2.9 and 2.7-fold higher than that of the parent CbFDHM2. The mutants had greater potential in CO2 reduction. The optimal temperature for V328I/F285W and V354G/F285W was 55 °C, and they showed increasement of relative activity under 45 °C to 55 °C compared with parent. The optimal pH for the mutants was 9.0, and they showed excellent stability in pH 4.0-11.5. The kcat/Km values of mutants were 1.75 times higher than that of the parent. Then the molecular basis for its improvement of biochemical characteristics were preliminarily elucidated by computer-aided methods. All of these results further established a solid foundation for molecular modification of formate dehydrogenase and CO2 reduction.


Assuntos
Dióxido de Carbono , Formiato Desidrogenases , Dióxido de Carbono/metabolismo , Formiato Desidrogenases/genética , Formiato Desidrogenases/química , Formiato Desidrogenases/metabolismo , Catálise , Formiatos/metabolismo
4.
J Exp Bot ; 73(5): 1370-1384, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-34849737

RESUMO

Fruit shape is an important quality and yield trait in melon (Cucumis melo). Although some quantitative trait loci for fruit shape have been reported in in this species, the genes responsible and the underlying mechanisms remain poorly understood. Here, we identified and characterized a gene controlling fruit shape from two melon inbred lines, B8 with long-horn fruit and HP22 with flat-round fruit. Genetic analysis suggested that the shape was controlled by a single and incompletely dominant locus, which we designate as CmFSI8/CmOFP13. This gene was finely mapped to a 53.7-kb interval on chromosome 8 based on bulked-segregant analysis sequencing and map-based cloning strategies. CmFSI8/CmOFP13 encodes an OVATE family protein (OFP) and is orthologous to AtOFP1 and SlOFP20. The transcription level of CmFSI8/CmOFP13 in the ovary of HP22 was significantly higher than that in B8, and sequence analysis showed that a 12.5-kb genomic variation with a retrotransposon insertion identified in the promoter was responsible for elevating the expression, and this ultimately caused the differences in fruit shape. Ectopic overexpression of CmFSI8/CmOFP13 in Arabidopsis led to multiple phenotypic changes, including kidney-shaped leaves and shortened siliques. Taken together, our results demonstrate the involvement of an OFP in regulating fruit shape in melon, and our improved understanding of the molecular mechanisms will enable us to better manipulate fruit shape in breeding.


Assuntos
Cucumis melo , Cucurbitaceae , Mapeamento Cromossômico , Cucumis melo/genética , Cucurbitaceae/genética , Frutas/genética , Genes de Plantas , Melhoramento Vegetal
5.
Bioorg Med Chem Lett ; 72: 128729, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35413415

RESUMO

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated encouraging clinical outcomes for patients with EGFR-mutated non-small cell lung cancer, a considerable number of patients will develop drug resistance and eventually undergo disease progression after taking EGFR-TKIs for a period of time. EGFRdel19/T790M/C797S and EGFRL858R/T790M/C797S are two most prevalent tertiary EGFR mutants identified in Osimertinib-resistant tumors and currently there is no therapy approved clinically targeting these mutants. In this study, we designed and synthesized a series of novel 4th generation EGFR inhibitors based on scaffold of Brigatinib. After extensive SAR studies, compound 23, the most promising candidate, exhibited strong biochemical potencies against EGFRdel19/T790M/C797S, EGFRL858R/T790M/C797S and other clinically relevant EGFR mutants while sparing wild type EGFR. In cellular assays, compound 23 potently inhibited proliferation of BaF3EGFR del19/T790M/C797S and PC-9EGFR del19/T790M/C797S. Moreover, compound 23 demonstrated good DMPK profile in mouse PK study.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Compostos Organofosforados , Inibidores de Proteínas Quinases/química , Pirimidinas
6.
Zhonghua Nan Ke Xue ; 28(5): 408-414, 2022 May.
Artigo em Zh | MEDLINE | ID: mdl-37477479

RESUMO

OBJECTIVE: To investigate the value of single-sperm sequencing technology in preimplantation genetic testing. METHODS: Haplotypes were constructed by single-sperm isolation combined with single-sperm sequencing for a patient with autosomal dominant polycystic kidney disease (ADPKD) caused by de novo mutation of the PKD1 gene c.3815T>G. 50. Single-sperm samples were isolated by mechanical braking, whole-genome amplification was performed, and mutation loci and their 187 upstream and downstream single nucleotide polymorphisms (SNP) were designed. The amplified products were verified for determination of the chromosome haplotypes carrying or not carrying pathogenic mutations. The embryos carrying pathogenic mutations were identified in 7 embryonic trophectoderm cell biopsy samples by high-throughput sequencing after whole-genome amplification. Available blastocysts were selected for embryo transfer, and amniotic fluid samples were collected at 18 weeks of gestation to determine whether the fetuses carried pathogenic mutations. RESULTS: A total of 30 SNPs were identified by single-sperm sequencing, and haplotypes were successfully constructed. Preimplantation haplotype analysis indicated that 5 embryos carried pathogenic mutations and 2 did not. mid-gestation amniotic fluid genetic testing revealed no PKD1 gene c.3815T>G mutation in the fetuses. CONCLUSION: SNPs can be identified by single-sperm sequencing in males carrying de novo pathogenic mutation, and haplotypes can be constructed by linkage analysis for preimplantation genetic testing of embryos.


Assuntos
Rim Policístico Autossômico Dominante , Diagnóstico Pré-Implantação , Gravidez , Feminino , Humanos , Masculino , Rim Policístico Autossômico Dominante/genética , Sêmen , Testes Genéticos , Mutação , Sequenciamento de Nucleotídeos em Larga Escala , Espermatozoides , Tecnologia
7.
Angew Chem Int Ed Engl ; 60(50): 26105-26114, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34590387

RESUMO

The autophagic ubiquitin-like protein LC3 functions through interactions with LC3-interaction regions (LIRs) of other autophagy proteins, including autophagy receptors, which stands out as a promising protein-protein interaction (PPI) target for the intervention of autophagy. Post-translational modifications like acetylation of Lys49 on the LIR-interacting surface could disrupt the interaction, offering an opportunity to design covalent small molecules interfering with the interface. Through screening covalent compounds, we discovered a small molecule modulator of LC3A/B that covalently modifies LC3A/B protein at Lys49. Activity-based protein profiling (ABPP) based evaluations reveal that a derivative molecule DC-LC3in-D5 exhibits a potent covalent reactivity and selectivity to LC3A/B in HeLa cells. DC-LC3in-D5 compromises LC3B lipidation in vitro and in HeLa cells, leading to deficiency in the formation of autophagic structures and autophagic substrate degradation. DC-LC3in-D5 could serve as a powerful tool for autophagy research as well as for therapeutic interventions.


Assuntos
Autofagia/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Células HeLa , Humanos , Modelos Moleculares , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química
8.
Anticancer Drugs ; 27(7): 669-78, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27139820

RESUMO

Cabozantinib capsules (COMETRIQ) are approved for the treatment of patients with progressive metastatic medullary thyroid cancer. Cabozantinib tablets are investigational drug products considered to be potentially preferred pharmaceutical dosing forms. Two phase I open-label single-dose studies in healthy individuals were carried out to characterize the plasma pharmacokinetics of cabozantinib capsule and tablet formulations: a two-way crossover bioequivalence study (n=77) comparing the tablet formulation and the marketed capsule formulation at the approved 140 mg dose and a dose-proportionality study (n=21 per treatment arm) evaluating the 20, 40, and 60 mg tablet strengths. In the bioequivalence study, plasma exposure [area under the plasma concentration-time curve (AUC0-t and AUC0-inf)] values were similar (<10% difference) for both formulations and the 90% confidence intervals (CIs) around the ratio of geometric least-squares means (GLSM) were within the accepted bioequivalence limits of 80-125%. However, the GLSM for Cmax was 19% higher for the tablet formulation and the upper 90% CI for the ratio of GLSM (131.65%) was beyond the 80-125% range. Thus, the tablet and capsule formulations failed to fulfill the bioequivalence study acceptance criteria. In the dose-proportionality study, single doses of the 20, 40, and 60 mg cabozantinib tablet strengths showed dose-proportional increases where the 95% CIs for the slopes of the ln-transformed Cmax, AUC0-t, and AUC0-inf values versus ln-transformed cabozantinib dose included the value of 1. These findings indicate that cabozantinib plasma exposures increased proportionally with increasing cabozantinib dose over the 20-60 mg tablet strength dose range.


Assuntos
Anilidas/administração & dosagem , Anilidas/farmacocinética , Piridinas/administração & dosagem , Piridinas/farmacocinética , Adolescente , Adulto , Anilidas/efeitos adversos , Anilidas/sangue , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Cápsulas , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Piridinas/efeitos adversos , Piridinas/sangue , Comprimidos , Equivalência Terapêutica , Adulto Jovem
9.
Mol Genet Genomic Med ; 12(3): e2343, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38156946

RESUMO

BACKGROUND: Meckel syndrome (MKS) is the most severe form of an autosomal recessive ciliopathy and is clinically characterized by occipital encephalocele, severely polycystic kidneys, and postaxial polydactyly (toes). The association of TXNDC15-related MKS has been reported. We report the case of a homozygous mutation in the TXNDC15 gene, causing MKS14 in the Chinese population. METHODS: The fetal skin tissue and parental peripheral blood were retained for whole-exome sequencing and Sanger sequencing, which investigated the potential pathogenic variants associated with MKS. RESULTS: The fetus was homozygous for a mutation in the TXNDC15 gene (NM_024715.3), specifically c.560delA (p.Asn187llefsTer4), and both parents were heterozygous for this mutation. CONCLUSION: Our study identified a new mutation that adds to the mutational landscape of MKS, which provide a basis for genetic counseling and the selection of reproductive options.


Assuntos
Transtornos da Motilidade Ciliar , Doenças Renais Policísticas , Retinose Pigmentar , Humanos , Encefalocele/genética , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/patologia , Transtornos da Motilidade Ciliar/genética , Transtornos da Motilidade Ciliar/patologia , Mutação
10.
Diabetes Metab Syndr Obes ; 16: 4215-4231, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38162802

RESUMO

Background: Diabetic kidney disease (DKD) is a chronic renal disease which could eventually develop into renal failure. Though albuminuria and estimated glomerular filtration rate (eGFR) are helpful for the diagnosis of DKD, the lack of specific biomarkers reduces the efficiency of therapeutic interventions. Methods: Based on bulk-seq of 56 urine samples collected at different time points (including 11 acquired from DKD patients and 11 from healthy controls), in corporation of scRNA-seq data of urine samples and snRNA-seq data of renal punctures from DKD patients (retrieved from NCBI GEO Omnibus), urine-kidney specific genes were identified by Multiple Biological Information methods. Results: Forty urine-kidney specific genes/differentially expressed genes (DEGs) were identified to be highly related to kidney injury and proteinuria for the DKD patients. Most of these genes participate in regulating glucagon and apoptosis, among which, urinary PART1 (mainly derived from distal tubular cells) and PLA2R1 (podocyte cell surface marker) could be used together for the early diagnosis of DKD. Moreover, urinary PART1 was significantly associated with multiple clinical indicators, and remained stable over time in urine. Conclusion: Urinary PART1 and PLA2R1 could be shed lights on the discovery and development of non-invasive diagnostic method for DKD, especially in early stages.

11.
World J Clin Cases ; 10(34): 12761-12767, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36579083

RESUMO

BACKGROUND: Acephalic spermatozoa syndrome (ASS) is an extremely rare form of severe teratozoospermia, where in most of the sperm either appear to lack heads or have disconnected or poorly connected heads and tails. CASE SUMMARY: We reported the case of a male patient with secondary infertility whose sperm showed typical ASS upon morphological analysis. Whole-exome sequencing was performed on the patient's peripheral blood, which revealed two heterozygous variants of the PMFBP1 gene: PMFBP1c.414+1G>T (p.?) and PMFBP1c.393del (p.C132Afs*3). CONCLUSION: It is speculated that the compound homozygous mutation of PMFBP1 may be the cause of ASS. We conducted a literature review in order to provide the basis for genetic counseling and clinical diagnosis of patients with ASS.

12.
Bioorg Med Chem Lett ; 21(12): 3578-82, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21602044

RESUMO

Newly developed monofluoromethylation reaction provided access to various bioactive molecules with an interesting monofluoromethyl unit. An iridium-catalyzed asymmetric version was employed for large-scale methyl-monofluorination of widely used nonsteroidal anti-inflammatory drug ibuprofen (the active S isoform). The methyl-monofluorinated ibuprofen was found to selectively inhibit cyclooxygenase-1 over cyclooxygenase-2 and surprisingly, the compound, with almost equal pharmacokinetic profile, was shown to increase analgesic activity and diminish gastric damage in animal models comparing to the parent drug ibuprofen. Therefore, methyl-monofluorination could be a useful strategy for improving efficacy and safety profile of drugs from the 'profen' family.


Assuntos
Ciclo-Oxigenase 1 , Inibidores de Ciclo-Oxigenase/síntese química , Inibidores de Ciclo-Oxigenase/farmacologia , Flúor/química , Mucosa Gástrica/efeitos dos fármacos , Ibuprofeno , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Células Cultivadas , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase/química , Humanos , Ibuprofeno/química , Ibuprofeno/farmacologia , Concentração Inibidora 50 , Metilação , Estrutura Molecular
13.
J Comput Aided Mol Des ; 25(9): 873-83, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21904909

RESUMO

The lymphoid tyrosine phosphatase (LYP), encoded by the PTPN22 gene, has recently been identified as a promising drug target for human autoimmunity diseases. Like the majority of protein-tyrosine phosphatases LYP can adopt two functionally distinct forms determined by the conformation of the WPD-loop. The WPD-loop plays an important role in the catalytic dephosphorylation by protein-tyrosine phosphatases. Here we investigate the binding modes of two chemotypes of small molecule LYP inhibitors with respect to both protein conformations using computational modeling. To evaluate binding in the active form, we built a LYP protein structure model of high quality. Our results suggest that the two different compound classes investigated, bind to different conformations of the LYP phosphatase domain. Binding to the closed form is facilitated by an interaction with Asp195 in the WPD-loop, presumably stabilizing the active conformation. The analysis presented here is relevant for the design of inhibitors that specifically target either the closed or the open conformation of LYP in order to achieve better selectivity over phosphatases with similar binding sites.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 22/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 22/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Domínio Catalítico , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 22/química
14.
Nucleic Acids Res ; 37(8): e59, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19293274

RESUMO

The full understanding of dynamics of cellular processes hinges on the development of efficient and non-invasive labels for intracellular RNA species. Light-up aptamers binding fluorogenic ligands show promise as specific labels for RNA species containing those aptamers. Herein, we took advantage of existing, non-light-up aptamers against small molecules and demonstrated a new class of light-up probes in vitro. We synthesized two conjugates of thiazole orange dye to small molecules (GMP and AMP) and characterized in vitro their interactions with corresponding RNA aptamers. The conjugates preserved specific binding to aptamers while showing several 100-fold increase in fluorescence of the dye (the 'light-up' property). In the presence of free small molecules, conjugates can be displaced from aptamers serving also as fluorescent sensors. Our in vitro results provide the proof-of-concept that the small-molecule conjugates with light-up properties can serve as a general approach to label RNA sequences containing aptamers.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Aptâmeros de Nucleotídeos/química , Corantes Fluorescentes/química , Guanosina Monofosfato/análogos & derivados , Tiazóis/química , Monofosfato de Adenosina/síntese química , Monofosfato de Adenosina/química , Guanosina Monofosfato/síntese química , Guanosina Monofosfato/química , Nucleotídeos/química , Espectrometria de Fluorescência , Tiazóis/síntese química
15.
ACS Nano ; 15(11): 18014-18022, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34677047

RESUMO

Molecular adsorption conformations and arrangement configurations on surfaces are important structural aspects of surface stereochemistry, but their roles in steering the structures of metal-organic networks (MONs) remain vague and unexplored. In this study, we constructed MONs by the coordination self-assembly of isocyanides on Cu(111) and Ag(111) surfaces and demonstrated that the MON structures can be steered by surface stereochemistry, including the adsorption conformations of the isocyanide molecules and the arrangement configurations of the coordination nodes and subunits. The coordination self-assembly of 1,4-phenylene diisocyanobenzene afforded a honeycomb MON consisting of 3-fold (isocyano)3-Cu motifs on a Cu(111) surface. In contrast, geometrically different chevron-shaped 1,3-phenylene diisocyanobenzene (m-DICB) failed to generate a MON, which is ascribable to its standing conformation on the Cu(111) surface. However, m-DICB was adsorbed in a flat conformation on a Ag(111) surface, which has a larger lattice constant than a Cu(111) surface, and smoothly underwent coordination self-assembly to form a MON consisting of (isocyano)3-Ag motifs. Interestingly, only C3-Ag nodes with heterotactic configurations could grow into larger subunits; those subunits with heterotactic configurations further grew into Sierpinski triangle fractals (up to fourth order), while subunits with homotactic configurations afforded a triangular MON.

16.
Front Bioeng Biotechnol ; 9: 655522, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33859982

RESUMO

Leucine dehydrogenase (LDH) is a NAD+-dependent oxidoreductase, which can selectively catalyze α-keto acids to obtain α-amino acids and their derivatives. It plays a key role in the biosynthesis of L-tert-leucine (L-Tle). As a non-naturally chiral amino acid, L-Tle can be used as an animal feed additive, nutrition fortifier, which is a perspective and important building block in the pharmaceutical, cosmetic, and food additive industry. In this study, four hypothetical leucine dehydrogenases were discovered by using genome mining technology, using the highly active leucine dehydrogenase LsLeuDH as a probe. These four leucine dehydrogenases were expressed in Escherichia coli BL21(DE3), respectively, and purified to homogeneity and characterized. Compared with the other enzymes, the specific activity of PfLeuDH also shows stronger advantage. In addition, the highly selective biosynthesis of L-Tle from trimethylpyruvic acid (TMP) was successfully carried out by whole-cell catalysis using engineered E. coli cells as biocatalyst, which can efficiently coexpress leucine dehydrogenase and formate dehydrogenase. One hundred-millimolar TMP was catalyzed for 25 h, and the yield and space-time yield of L-Tle reached 87.38% (e.e. >99.99%) and 10.90 g L-1 day-1. In short, this research has initially achieved the biosynthesis of L-Tle, laying a solid foundation for the realization of low-cost and large-scale biosynthesis of L-Tle.

17.
Nicotine Tob Res ; 12(2): 105-16, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20026503

RESUMO

INTRODUCTION: It has been reported that adult smokers (AS) may be considering smokeless tobacco products as an alternative to smoking. The objective of this study was to evaluate the change in exposure in AS using Marlboro snus (MSNUS) (a tobacco pouch product in test market in June 2007). METHODS: AS were randomized into the following groups--CS: subjects (n = 30) continue smoking their own brand; DU: subjects (n = 60) reduced their daily cigarette consumption by >or=50% and were allowed to use MSNUS; SN: subjects (n = 15) stopped smoking their cigarettes but were allowed to use MSNUS; NT: subjects (n = 15) were not allowed to use any tobacco products for the entire duration of the 8-day study. Biomarkers of smoke exposure (BOE) measured at baseline and postbaseline were 24-hr urinary excretion of metabolites of N-nitrosamines, nicotine (urine and plasma), aromatic amines, benzene, and polycyclic aromatic hydrocarbon; urine mutagenicity; and carboxyhemoglobin at various timepoints. RESULTS: Statistically significant (p < .05) reductions in all the urinary BOE were observed in the DU group compared with the CS group. After correcting for the residual effect, a proportionate reduction (approximately 50%) in most of the biomarkers was observed. Even larger reductions, similar to the NT group, were observed in the SN group. DISCUSSION: The proportionate reduction in exposure when reducing the number of cigarettes by 50% and using MSNUS, under the consumption patterns observed, suggest that the AS did not appear to alter their smoking behavior. The added exposure from MSNUS usage in this group was minimal. The AS sustained substantial reductions in exposure when using MSNUS exclusively.


Assuntos
Monitoramento Ambiental/métodos , Exposição por Inalação/análise , Nicotina/urina , Fumaça/análise , Fumar/urina , Tabaco sem Fumaça/análise , Administração por Inalação , Adulto , Biomarcadores/urina , Butadienos/urina , Monóxido de Carbono/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrosaminas/urina , Pirenos/análise , Adulto Jovem
20.
Bioorg Med Chem Lett ; 19(8): 2354-9, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19303288

RESUMO

Soluble epoxide hydrolase (sEH) is a novel target for the treatment of hypertension and vascular inflammation. A new class of potent non-urea sEH inhibitors was identified via high throughput screening (HTS) and chemical modification. IC(50)s of the most potent compounds range from micromolar to low nanomolar.


Assuntos
Descoberta de Drogas/métodos , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Ureia/metabolismo , Humanos , Solubilidade , Relação Estrutura-Atividade , Ureia/química , Ureia/classificação , Ureia/farmacologia
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