RESUMO
The personalized approach in sports genetics implies considering the allelic variants of genes in polymorphic loci when adjusting the training process of athletes. The personalized approach is used both in sports genetics and in medicine to identify the influence of genotype on the manifestations of human physical qualities that allow to achieve high sports results or to assess the impact of genotype on the development and course of diseases. The impact of genes of the renin-angiotensin and kinin-bradykinin systems in the development of cardiovascular disease in athletes has not been defined. This study aims to determine the polymorphisms of four genes (ACE, BDKRB2, PPARGC1A and NOS3) and the total genetic score to reveal the predisposition to the formation of physical qualities in martial arts athletes with different athletic abilities. The products of these four genes are involved in the control of blood pressure. The allelic variants of these genes are associated with the development of the physical quality "endurance" and have an indirect influence on the formation of speed and power qualities. The total genetic score (TGS: from 0 to 100 arbitrary units) was calculated from the genotype score in each polymorphism. The athletes were divided into Group I with high and Group II with low qualifications depending on their sports success. Single nucleotide polymorphisms (SNPs) are identified through restriction endonucleases cleavage for PCR amplicons for discriminating between alleles of the target genes ACE (rs4646994), BDKRB2 (rs5810761), PPARGC1A (rs8192673) and NOS3 (rs1799983). Significant differences between the allelic variants of target genes and athletic ability were found between Group I and Group II for genotype G/G of NOS3 gene and genotypes Gly/Gly and Gly/Ser of PPARGC1A gene. The data obtained confirm that athletes with unfavourable genotypes are excluded in the screening phase because their endurance is not fully developed to the required level in martial arts. Martial arts athletes with the highest TGS have the highest skill level. Polymorphic loci of four genes whose products are involved in blood pressure control (ACE, BDKRB2, NOS3 and PPARGC1A) can be used in martial arts not only to determine predisposition to cardiovascular disease but also to predispose to the development of speed and power qualities and endurance. The total genetic score can serve as a tool for predicting athletic success.
Assuntos
Desempenho Atlético , Doenças Cardiovasculares , Artes Marciais , Angiotensinas , Atletas , Desempenho Atlético/fisiologia , Bradicinina , Enzimas de Restrição do DNA , Humanos , Polimorfismo de Nucleotídeo Único , ReninaRESUMO
OBJECTIVES: To investigate the molecular epidemiology and antimicrobial susceptibility of Clostridioides difficile isolates from patients with C. difficile infection (CDI) from two Phase 3 clinical trials of surotomycin. METHODS: In both trials [Protocol MK-4261-005 (NCT01597505) conducted across Europe, North America and Israel; and Protocol MK-4261-006 (NCT01598311) conducted across North America, Asia-Pacific and South America], patients with CDI were randomized (1:1) to receive oral surotomycin (250 mg twice daily) or oral vancomycin (125 mg four times per day) for 10 days. Stool samples were collected at baseline and C. difficile isolates were characterized by restriction endonuclease analysis (REA) and PCR ribotyping. Susceptibility testing was performed by agar dilution, according to CLSI recommendations. RESULTS: In total, 1147 patients were included in the microbiological modified ITT population. Of 992 recovered isolates, 922 (92.9%) were typed. There was a high association between REA groups and their corresponding predominant PCR ribotype (RT) for BI, DH, G and CF strains. REA group A showed more diverse PCR RTs. Overall, the most common strain was BI/RT027 (20.3%) followed by Y/RT014/020 (15.0%) and DH/RT106 (7.2%). The BI/RT027 strain was particularly prevalent in Europe (29.9%) and Canada (23.6%), with lower prevalence in the USA (16.8%) and Australia/New Zealand (3.4%). Resistance was most prevalent in the BI/RT027 strain, particularly to metronidazole, vancomycin and moxifloxacin. CONCLUSIONS: A wide variation in C. difficile strains, both within and across different geographical regions, was documented by both REA and ribotyping, which showed overall good correlation.
Assuntos
Anti-Infecciosos , Clostridioides difficile , Infecções por Clostridium , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ásia , Canadá , Clostridioides , Clostridioides difficile/genética , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/epidemiologia , Enzimas de Restrição do DNA , Europa (Continente) , Humanos , Israel , Lipopeptídeos , Testes de Sensibilidade Microbiana , América do Norte , Peptídeos Cíclicos , Reação em Cadeia da Polimerase , Proibitinas , Ribotipagem , América do SulRESUMO
To date, studies on the application of loop-mediated isothermal amplification (LAMP) in the detection of genetically modified organisms (GMOs) are stably increasing and demonstrates LAMP is a potential and promising method for on spot identification of GMOs. However, little information is known for detection of GM potato events by LAMP. In this report, we developed an optimized and visual LAMP assay with high specificity and sensitivity to rapidly amplify genomic DNA of potato EH92-527-1 within 45 min. The limit of detection of LAMP in our study is 10-fold higher than the conventional PCR. Furthermore, LAMP products can be directly observed via naked eyes by addition of SYBR Green I without gel electrophoresis analysis and PCR-based equipment. Therefore, the LAMP assay developed in this paper provides an efficient, convenient and cost-effective tool for the detection of GM potato EH92-527-1.
Assuntos
DNA de Plantas/genética , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/métodos , Solanum tuberosum/genética , Sequência de Bases/genética , Benzotiazóis , Percepção de Cores , Primers do DNA/genética , Enzimas de Restrição do DNA/genética , Diaminas , Eletroforese em Gel de Ágar , Corantes Fluorescentes/química , Contaminação de Alimentos/análise , Amplificação de Genes , Limite de Detecção , Compostos Orgânicos/química , Reação em Cadeia da Polimerase/economia , Quinolinas , Sensibilidade e Especificidade , Temperatura , TempoRESUMO
OBJECTIVE: We investigated whether vitamin D receptor (VDR) polymorphisms are associated with circulating metabolic biomarkers and anthropometric measures changes in breast cancer survivors supplemented with vitamin D3. METHODS: One hundred sixty-eight breast cancer survivors admitted to Shohaday-e-Tajrish hospital received 4000 IU of daily vitamin D3 supplements for 12 weeks. Anthropometric measurements as well dietary, physical activity and plasma metabolic biomarkers assessments were performed before and after intervention. VDR polymorphisms were considered as the main exposures. Multivariate multiple linear regression analyses were used to determine the association between the VDR single-nucleotide polymorphisms (SNPs) and changes in metabolic and anthropometric measures in response to vitamin D3 supplementation. RESULTS: One hundred twenty-five (85%) women had insufficient and inadequate levels of plasma 25-hydroxy vitamin D (25(OH)D) at baseline. Compared to the AA genotype of the ApaI, the aa category showed greater increase in muscle mass [71.3(10.7131.9)] and higher decrease in LDL-C [- 17.9(- 33.6, - 2.3)] levels after adjustment for potential confounders. In addition, the heterozygous genotype (Bb) of the BsmI VDR was associated with higher increase in WC following vitamin D3 supplementation, compared to BB [2.7(0.1,5.3)]. Haplotype score analyses indicate a significant association between inferred haplotypes from BsmI, ApaI, TaqI and FokI, BsmI and Cdx2 VDR polymorphisms and on-study visceral fat changes. CONCLUSIONS: Findings of this study showed that genetic variation in the VDR gene was associated with changes in cardio-metabolic parameters in breast cancer survivors, supplemented with vitamin D3, results could provide a novel insight into better understanding of which subset of individuals benefit most from normalization of vitamin D status. TRIAL REGISTRATION: This trial has been registered on the Iranian Registry of Clinical Trials (IRCT) under the identification code: IRCT2017091736244N1, registration date: 2017-11-10, http://www.irct.ir/trial/27153 and was approved by the ethics committees of the National Nutrition and Food Technology Research Institute (NNFTRI), Shahid Beheshti University of Medical Sciences (SBMU).
Assuntos
Neoplasias da Mama/genética , Colecalciferol/administração & dosagem , Suplementos Nutricionais , Metabolismo dos Lipídeos/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Adulto , Antropometria , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Sobreviventes de Câncer , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Enzimas de Restrição do DNA/química , Feminino , Expressão Gênica , Genótipo , Heterozigoto , Humanos , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/metabolismo , Pessoa de Meia-Idade , Análise Multivariada , Receptores de Calcitriol/metabolismo , Triglicerídeos/sangue , Vitamina D/análogos & derivados , Vitamina D/sangue , Circunferência da CinturaRESUMO
Taking advantage of "Y" junction structure and restriction endonuclease assisted cyclic enzymatic amplification, a dual-probe electrochemical DNA (DE-DNA) biosensor was designed to detect double-stranded DNA (dsDNA) of acute promyelocytic leukemia (APL) related gene. Two groups of detection probes were designed, and each group was composed of a biotinylated capture probe and an assisted probe. They were separately complementary with two strands of target dsDNA in order to prevent the reannealing of the two separate strands from target dsDNA. First, thiol functionalized capture probes (C1 and C2) were severally assembled onto two different gold electrodes, followed by hybridizing with target dsDNA (S1a-S1b) and assistant probes to form two Y-junction-structure ternary complexes. Subsequently, restriction sites on the ternary complexes were digested by Rsa I, which can release S1a, S1b and biotins from the electrode surfaces. Meanwhile, the released S1a and S1b can further hybridize with the unhybridized corresponding detection probes and then initiate another new hybridization-cleavage-separation cycle. Finally, the current signals were produced by the enzyme-catalyzed reaction of streptavidin-horse reddish peroxidase (streptavidin-HRP). The distinct difference in current signals between different sequences allowed detection of target dsDNA down to a low detection limit of 47 fM and presented excellent specificity with discriminating only a single-base mismatched dsDNA sequence. Moreover, this biosensor was also used for assay of polymerase chain reaction (PCR) samples with satisfactory results. According to the results, the power of the DE-DNA biosensor as a promising tool for the detection of APL and other diseases.
Assuntos
Condutometria/instrumentação , Sondas de DNA/genética , DNA/genética , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Receptores do Ácido Retinoico/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Sequência de Bases , DNA/análise , DNA/química , Sondas de DNA/química , Enzimas de Restrição do DNA/química , Enzimas de Restrição do DNA/genética , Desenho de Equipamento , Análise de Falha de Equipamento , Dados de Sequência Molecular , Proteínas Nucleares/análise , Proteínas Nucleares/química , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Proteína da Leucemia Promielocítica , Receptores do Ácido Retinoico/análise , Receptores do Ácido Retinoico/química , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/genética , Reprodutibilidade dos Testes , Receptor alfa de Ácido Retinoico , Sensibilidade e Especificidade , Análise de Sequência de DNA/instrumentação , Fatores de Transcrição/análise , Fatores de Transcrição/química , Proteínas Supressoras de Tumor/análise , Proteínas Supressoras de Tumor/químicaRESUMO
Potato is the third largest food crop in the world, however, the high degree of heterozygosity, the tetrasomic inheritance and severe inbreeding depression are major difficulties for conventional potato breeding. The rapid development of modern breeding methods offers new possibilities to enhance breeding efficiency and precise improvement of desirable traits. New site-directed mutagenesis techniques that can directly edit the target genes without any integration of recombinant DNA are especially favorable. Here we present a successful pipeline for site-directed mutagenesis in tetraploid potato through transient TALEN expression in protoplasts. The transfection efficiency of protoplasts was 38-39% and the site-directed mutation frequency was 7-8% with a few base deletions as the predominant type of mutation. Among the protoplast-derived calli, 11-13% showed mutations and a similar frequency (10%) was observed in the regenerated shoots. Our results indicate that the site-directed mutagenesis technology could be used as a new breeding method in potato as well as for functional analysis of important genes to promote sustainable potato production.
Assuntos
Enzimas de Restrição do DNA/metabolismo , Mutagênese Sítio-Dirigida/métodos , Melhoramento Vegetal/métodos , Poliploidia , Protoplastos/metabolismo , Solanum tuberosum/genética , Transfecção/métodos , Sequência de Bases , Perfilação da Expressão Gênica , Genoma de Planta/genética , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
Fraxetin is one of the main constituents of the traditional medicinal plant Fraxinus rhynchophylla. The inhibitory effect of fraxetin on various bacterial strains has been extensively reported, however, its mechanism of action on bacterial cells remains to be elucidated. In the present study, the antibacterial mechanism of fraxetin on Staphylococcus aureus was systematically investigated by examining its effect on cell membranes, protein synthesis, nucleic acid content and topoisomerase activity. The results indicated that fraxetin increased the permeability of the cell membrane but did not render it permeable to macromolecules, such as DNA and RNA. Additionally, the quantity of protein, DNA and RNA decreased to 55.74, 33.86 and 48.96%, respectively following treatment with fraxetin for 16 h. The activity of topoisomerase I and topoisomerase II were also markedly inhibited as fraxetin concentration increased. The result of the ultravioletvisible spectrophotometry demonstrated that the DNA characteristics exhibited a blue shift and hypochromic effect following treatment with fraxetin. These results indicated that fraxetin had a marked inhibitory effect on S.aureus proliferation. Further mechanistic studies showed that fraxetin could disrupt nucleic acid and protein synthesis by preventing topoisomerase from binding to DNA.
Assuntos
Antibacterianos/farmacologia , Cumarínicos/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Proteínas de Bactérias/biossíntese , Membrana Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Enzimas de Restrição do DNA/antagonistas & inibidores , Enzimas de Restrição do DNA/metabolismo , DNA Topoisomerases/metabolismo , DNA Bacteriano/biossíntese , Viabilidade Microbiana/efeitos dos fármacos , Ligação Proteica , Biossíntese de Proteínas/efeitos dos fármacos , Mapeamento por Restrição , Staphylococcus aureus/metabolismo , Inibidores da Topoisomerase/farmacologiaRESUMO
Single nucleotide polymorphisms (SNP) is an important molecular marker in traditional Chinese medicine research, and it is widely used in TCM authentication. The present study created a new genotyping method by combining restriction endonuclease digesting with melting curve analysis, which is a stable, rapid and easy doing SNP genotyping method. The new method analyzed SNP genotyping of two chloroplast SNP which was located in or out of the endonuclease recognition site, the results showed that when attaching a 14 bp GC-clamp (cggcgggagggcgg) to 5' end of the primer and selecting suited endonuclease to digest the amplification products, the melting curve of Lonicera japonica and Atractylodes macrocephala were all of double peaks and the adulterants Shan-yin-hua and A. lancea were of single peaks. The results indicated that the method had good stability and reproducibility for identifying authentic medicines from its adulterants. It is a potential SNP genotyping method and named restriction endonuclease digest - melting curve analysis.
Assuntos
Atractylodes/genética , Enzimas de Restrição do DNA/metabolismo , Contaminação de Medicamentos , Lonicera/genética , Plantas Medicinais/genética , Polimorfismo de Nucleotídeo Único , Atractylodes/classificação , DNA de Plantas/genética , Genótipo , Lonicera/classificação , Plantas Medicinais/classificaçãoRESUMO
ß-Adrenergic agonists (ß-agonists) are illegally used in animal husbandry, threatening the health of consumers. To realize multianalyte detection of ß-agonists, a ß2-adrenergic receptor (ß2-AR) was cloned from Syrian hamster lung and heterogeneously expressed by Spodoptera frugiperda (Sf9) cells. The recombinant ß2-AR was purified from intracellular soluble proteins of infected Sf9 cells, and was utilized to establish an enzyme-linked-receptor assay (ELRA) to detect a group of ß-agonists simultaneously. This assay was based on direct competitive inhibition of binding of horseradish peroxidase-labeled ractopamine to the immobilized ß2-AR proteins by ß-agonists. The IC50 and limit of detection values for ractopamine were 30.38µgL(-1) and 5.20µgL(-1), respectively. Clenbuterol and salbutamol showed 87.7% and 58.5% cross-reactivities with ractopamine, respectively. This assay is simple, rapid, and environmentally friendly, showing a potential application in the screening of ß-agonists in animal feeds.
Assuntos
Agonistas Adrenérgicos beta/análise , Técnicas Biossensoriais/métodos , Enzimas de Restrição do DNA/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Baculoviridae/genética , Clonagem Molecular , Avaliação Pré-Clínica de Medicamentos , Mesocricetus , Receptores Adrenérgicos beta 2/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células Sf9 , SpodopteraRESUMO
Site-selective scission of genomes is quite important for future biotechnology. However, naturally occurring restriction enzymes cut these huge DNAs at too many sites and cannot be used for this purpose. Recently, we have developed a completely chemistry-based artificial restriction DNA cutter (ARCUT) by combining a pair of pseudo-complementary PNA (pcPNA) strands (sequence recognition moiety) and Ce(IV)/EDTA complex (molecular scissors). The scission site of ARCUT and its scission specificity can be freely modulated in terms of the sequences and lengths of the pcPNA strands so that even huge genomes can be selectively cut at only one predetermined site. In this chapter, the method of site-selective scission of human genomic DNA using ARCUT is described in detail.
Assuntos
Materiais Biomiméticos/metabolismo , Enzimas de Restrição do DNA/metabolismo , DNA/metabolismo , Genoma Humano/genética , Ácidos Nucleicos Peptídicos/metabolismo , Sequência de Bases , Sítios de Ligação , Materiais Biomiméticos/química , Cério/química , DNA/genética , Ácido Edético/química , Humanos , Hidrólise , Compostos Organometálicos/química , Ácidos Nucleicos Peptídicos/química , Ácidos Nucleicos Peptídicos/genética , Especificidade por SubstratoRESUMO
Single nucleotide polymorphisms (SNP) is an important molecular marker in traditional Chinese medicine research, and it is widely used in TCM authentication. The present study created a new genotyping method by combining restriction endonuclease digesting with melting curve analysis, which is a stable, rapid and easy doing SNP genotyping method. The new method analyzed SNP genotyping of two chloroplast SNP which was located in or out of the endonuclease recognition site, the results showed that when attaching a 14 bp GC-clamp (cggcgggagggcgg) to 5' end of the primer and selecting suited endonuclease to digest the amplification products, the melting curve of Lonicera japonica and Atractylodes macrocephala were all of double peaks and the adulterants Shan-yin-hua and A. lancea were of single peaks. The results indicated that the method had good stability and reproducibility for identifying authentic medicines from its adulterants. It is a potential SNP genotyping method and named restriction endonuclease digest - melting curve analysis.
Assuntos
Atractylodes , Classificação , Genética , Enzimas de Restrição do DNA , Metabolismo , DNA de Plantas , Genética , Contaminação de Medicamentos , Genótipo , Lonicera , Classificação , Genética , Plantas Medicinais , Classificação , Genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In seasonally breeding vertebrates, changes in day length induce categorically distinct behavioral and reproductive phenotypes via thyroid hormone-dependent mechanisms. Winter photoperiods inhibit reproductive neuroendocrine function but cannot sustain this inhibition beyond 6 mo, ensuring vernal reproductive recrudescence. This genomic plasticity suggests a role for epigenetics in the establishment of seasonal reproductive phenotypes. Here, we report that DNA methylation of the proximal promoter for the type III deiodinase (dio3) gene in the hamster hypothalamus is reversible and critical for photoperiodic time measurement. Short photoperiods and winter-like melatonin inhibited hypothalamic DNA methyltransferase expression and reduced dio3 promoter DNA methylation, which up-regulated dio3 expression and induced gonadal regression. Hypermethylation attenuated reproductive responses to short photoperiods. Vernal refractoriness to short photoperiods reestablished summer-like methylation of the dio3 promoter, dio3 expression, and reproductive competence, revealing a dynamic and reversible mechanism of DNA methylation in the mammalian brain that plays a central role in physiological orientation in time.
Assuntos
Metilação de DNA/fisiologia , Epigênese Genética/fisiologia , Regulação da Expressão Gênica/fisiologia , Fotoperíodo , Estações do Ano , Percepção do Tempo/fisiologia , Análise de Variância , Animais , Cricetinae , Enzimas de Restrição do DNA , Ensaio de Imunoadsorção Enzimática , Feminino , Hipotálamo/metabolismo , Imuno-Histoquímica , Iodeto Peroxidase/metabolismo , Masculino , Phodopus , Análise de Sequência de DNARESUMO
High soil phosphorus (P) concentration is frequently shown to reduce root colonization by arbuscular mycorrhizal (AM) fungi, but the influence of P on the diversity of colonizing AM fungi is uncertain. We used terminal restriction fragment length polymorphism (T-RFLP) of 18S rDNA and cloning to assess diversity of AM fungi colonizing maize (Zea mays), soybean (Glycene max) and field violet (Viola arvensis) at three time points in one season along a P gradient of 10-280 mg l(-1) in the field. Percentage AM colonization changed between sampling time points but was not reduced by high soil P except in maize. There was no significant difference in AM diversity between sampling time points. Diversity was reduced at concentrations of P > 25 mg l(-1), particularly in maize and soybean. Both cloning and T-RFLP indicated differences between AM communities in the different host species. Host species was more important than soil P in determining the AM community, except at the highest P concentration. Our results show that the impact of soil P on the diversity of AM fungi colonizing plants was broadly similar, despite the fact that different plants contained different communities. However, subtle differences in the response of the AM community in each host were evident.
Assuntos
Micorrizas/efeitos dos fármacos , Micorrizas/fisiologia , Fósforo/farmacologia , Plantas/efeitos dos fármacos , Plantas/microbiologia , Solo/química , Análise por Conglomerados , Contagem de Colônia Microbiana , Enzimas de Restrição do DNA/metabolismo , Micorrizas/crescimento & desenvolvimento , Glycine max/microbiologia , Fatores de Tempo , Viola/microbiologia , Zea mays/microbiologiaRESUMO
Green tea polyphenols (GTP) are widely believed to function as antioxidants and antimicrobial agents. Here we observed that GTP and epigallocatechin gallate, the most abundant catechin in GTP, could also function as prooxidants and produce hydrogen peroxide (H2O2) to inhibit the growth of Pseudomonas aeruginosa. pH value of the medium was the key factor that affected prooxidant versus antioxidant property of GTP. Under weakly acidic conditions (pH 5.5-6.5), GTP showed antioxidant activity by eliminating H2O2; whereas, under neutral and weakly alkaline conditions (pH 7.0-8.0), GTP showed prooxidant activity and inhibited the growth of P. aeruginosa. Furthermore, we studied the effects of GTP on gene expression profiles of a few oxidative stress-related genes by quantitative real-time PCR analysis. After 10 min to 1 h of exposure under weakly alkaline condition, GTP significantly up-regulated expression levels of katB, sodM, ohr, lexA, and recN gene. These findings highlight that the pH-dependent H2O2 production by GTP contributes to the antibacterial activity and can induce oxidative stress-related responses in P. aeruginosa.
Assuntos
Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/farmacologia , Chá/química , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Catequina/análogos & derivados , Catequina/farmacologia , Enzimas de Restrição do DNA/genética , Enzimas de Restrição do DNA/metabolismo , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Extratos Vegetais/análise , Polifenóis/análise , Pseudomonas aeruginosa/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/análise , Reação em Cadeia da Polimerase em Tempo Real , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Regulação para CimaRESUMO
The Type ISP Restriction-Modification (RM) enzyme LlaBIII is encoded on plasmid pJW566 and can protect Lactococcus lactis strains against bacteriophage infections in milk fermentations. It is a single polypeptide RM enzyme comprising Mrr endonuclease, DNA helicase, adenine methyltransferase and target-recognition domains. LlaBIII shares >95% amino acid sequence homology across its first three protein domains with the Type ISP enzyme LlaGI. Here, we determine the recognition sequence of LlaBIII (5'-TnAGCC-3', where the adenine complementary to the underlined base is methylated), and characterize its enzyme activities. LlaBIII shares key enzymatic features with LlaGI; namely, adenosine triphosphate-dependent DNA translocation (â¼309 bp/s at 25°C) and a requirement for DNA cleavage of two recognition sites in an inverted head-to-head repeat. However, LlaBIII requires K(+) ions to prevent non-specific DNA cleavage, conditions which affect the translocation and cleavage properties of LlaGI. By identifying the locations of the non-specific dsDNA breaks introduced by LlaGI or LlaBIII under different buffer conditions, we validate that the Type ISP RM enzymes use a common translocation-collision mechanism to trigger endonuclease activity. In their favoured in vitro buffer, both LlaGI and LlaBIII produce a normal distribution of random cleavage loci centred midway between the sites. In contrast, LlaGI in K(+) ions produces a far more distributive cleavage profile.
Assuntos
Clivagem do DNA , Enzimas de Restrição do DNA/metabolismo , DNA/química , DNA/metabolismo , Metilação de DNA , Enzimas de Restrição do DNA/química , Enzimas de Restrição do DNA/classificação , Cloreto de Potássio/química , Estrutura Terciária de ProteínaRESUMO
Recent genome-wide mapping of nucleosome positions revealed that well-positioned nucleosomes are pervasive across eukaryotic genomes, especially in important regulatory regions such as promoters or origins of replication. As nucleosomes impede access to DNA, their positioning is a primary mode of genome regulation. In vivo studies, especially in yeast, shed some light on factors involved in nucleosome positioning, but there is an urgent need for a complementary biochemical approach in order to confirm their direct roles, identify missing factors, and study their mechanisms. Here we describe a method that allows the genome-wide in vitro reconstitution of nucleosomes with very in vivo-like positions by a combination of salt gradient dialysis reconstitution, yeast whole cell extracts, and ATP. This system provides a starting point and positive control for the biochemical dissection of nucleosome positioning mechanisms.
Assuntos
Cromatina/genética , DNA Fúngico/química , Genoma Fúngico , Nucleossomos/genética , Saccharomyces cerevisiae/genética , Trifosfato de Adenosina/metabolismo , Animais , Cromatina/química , Montagem e Desmontagem da Cromatina , Enzimas de Restrição do DNA/química , DNA Fúngico/genética , Diálise/métodos , Drosophila/química , Drosophila/genética , Eletroforese em Gel de Poliacrilamida , Eletroporação/métodos , Escherichia coli/química , Escherichia coli/genética , Biblioteca Genômica , Histonas/química , Histonas/genética , Nuclease do Micrococo/química , Conformação de Ácido Nucleico , Nucleossomos/química , Plasmídeos/química , Plasmídeos/genética , Saccharomyces cerevisiae/química , Cloreto de Sódio/química , Titulometria/métodosRESUMO
BACKGROUND: Dried root of Sophora flavescens Ait. is a medicinal material occasionally misused or adulterated by other species similar in appearance. In this study the internal transcribed spacer (ITS) regions of DNA samples of S. flavescens Ait. collected from different areas of Taiwan were amplified by polymerase chain reaction (PCR) and compared. The effectiveness of using ITS2 PCR restriction fragment length polymorphism (RFLP)-generated markers to differentiate S. flavescens Ait. from possible adulterants was also evaluated. RESULTS: The S. flavescens Ait. samples collected from different areas were extremely low in ITS sequence variability at species level. ITS2 PCR-RFLP coupled with restriction enzymes Sac I, Sac II, Xho I or Pvu I produced specific fragments for all tested variants. ITS2 PCR-RFLP coupled with Sac II was further performed to identify mixtures of DNA extracts of S. flavescens Ait. and Sophora tomentosa L. in various ratios. The developed ITS2 PCR-RFLP markers could detect mixed DNA samples of S. flavescens Ait./S. tomentosa L. up to a ratio of 10:1. CONCLUSION: The present study demonstrates the usefulness of ITS2 PCR-RFLP coupled with pre-selected restriction enzymes for practical and accurate authentication of S. flavescens Ait. The technique is also suitable for analysing S. flavescens Ait. mixed with other adulterants.
Assuntos
DNA Intergênico/metabolismo , DNA de Plantas/metabolismo , Raízes de Plantas/metabolismo , Polimorfismo de Fragmento de Restrição , Sophora/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Sequência de Bases , China , Enzimas de Restrição do DNA/metabolismo , DNA Intergênico/química , DNA de Plantas/química , Bases de Dados de Ácidos Nucleicos , Medicamentos de Ervas Chinesas/análise , Marcadores Genéticos , Glycyrrhiza uralensis/genética , Glycyrrhiza uralensis/metabolismo , Dados de Sequência Molecular , Filogenia , Mapeamento por Restrição , Alinhamento de Sequência , Sophora/metabolismo , Especificidade da Espécie , TaiwanRESUMO
BACKGROUND: Cloning vectors capable of retroviral transduction have enabled stable gene overexpression in numerous mitotic cell lines. However, the relatively small number of feasible restriction enzyme sequences in their cloning sites can hinder successful generation of overexpression constructs if these sequences are also present in the target cDNA insert. RESULTS: Utilizing ligation-independent cloning (LIC) technology, we have modified the highly efficient retroviral transduction vector, pBABE, to eliminate reliance on restriction enzymes for cloning. Instead, the modified plasmid, pBLIC, utilizes random 12/13-base overhangs generated by T4 DNA polymerase 3' exonuclease activity. PCR-based introduction of the complementary sequence into any cDNA of interest enables universal cloning into pBLIC. Here we describe creation of the pBLIC plasmid, and demonstrate successful cloning and protein overexpression from three different cDNAs, Bax, catalase, and p53 through transduction into the human prostate cancer cell line, LNCaP or the human lung cancer line, H358. CONCLUSIONS: Our results show that pBLIC vector retains the high transduction efficiency of the original pBABE while eliminating the requirement for checking individual cDNA inserts for internal restriction sites. Thus it comprises an effective retroviral cloning system for laboratory-scale stable gene overexpression or for high-throughput applications such as creation of retroviral cDNA libraries. To our knowledge, pBLIC is the first LIC vector for retroviral transduction-mediated stable gene expression in mammalian cells.
Assuntos
Clonagem Molecular/métodos , Vetores Genéticos , Retroviridae/genética , Transdução Genética , Catalase/biossíntese , Catalase/genética , Linhagem Celular Tumoral , Enzimas de Restrição do DNA/metabolismo , DNA Complementar/genética , DNA Complementar/metabolismo , Expressão Gênica , Humanos , Plasmídeos , Reprodutibilidade dos Testes , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Proteína X Associada a bcl-2/biossíntese , Proteína X Associada a bcl-2/genéticaRESUMO
In our screening for photosensitizers from natural resources, four alkaloids were isolated from Glycosmis pentaphylla by various chromatography techniques. Their structures were identified as glycoborinine (1), glybomine B (2), carbalexin A (3) and N-p-coumaroyltyramine (4) by spectral analysis. Their photoactivated antimicrobial activities were evaluated by thin-layer chromatography (TLC) agar overlay assay against Staphylococcus aureus and Bacillus subtilis. It was found that compounds 1 and 4 showed photo-activated antimicrobial activities. Meantime, photo-activated DNA binding activities of these compounds were also assessed by using a specially prepared 1.8 kb DNA fragment and restriction enzymes. Under UVA irradiation, compound 1 showed moderate inhibition on Nde I, Xba I, Nco I and Bcl I which have either 5'-TpA or 5'-ApT and trace or no inhibition on other restriction enzymes. It showed a similar inhibition pattern with the reference 8-methoxypsoralen. However, compounds 2-4 showed no inhibition against any of the restriction enzymes.
Assuntos
Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Carbazóis/farmacologia , Rutaceae/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Carbazóis/química , Carbazóis/isolamento & purificação , Cromatografia em Camada Fina , Ácidos Cumáricos/química , Ácidos Cumáricos/isolamento & purificação , Ácidos Cumáricos/farmacologia , Fragmentação do DNA , Enzimas de Restrição do DNA/metabolismo , Luz , Estrutura Molecular , Fármacos Fotossensibilizantes/farmacologia , Plantas Medicinais/química , Ligação Proteica , Raios UltravioletaRESUMO
In our screening for photosensitizers from natural resources, four alkaloids were isolated from Glycosmis pentaphylla by various chromatography techniques. Their structures were identified as glycoborinine (1), glybomine B (2), carbalexin A (3) and N-p-coumaroyltyramine (4) by spectral analysis. Their photoactivated antimicrobial activities were evaluated by thin-layer chromatography (TLC) agar overlay assay against Staphylococcus aureus and Bacillus subtilis. It was found that compounds 1 and 4 showed photo-activated antimicrobial activities. Meantime, photo-activated DNA binding activities of these compounds were also assessed by using a specially prepared 1.8 kb DNA fragment and restriction enzymes. Under UVA irradiation, compound 1 showed moderate inhibition on Nde I, Xba I, Nco I and Bcl I which have either 5'-TpA or 5'-ApT and trace or no inhibition on other restriction enzymes. It showed a similar inhibition pattern with the reference 8-methoxypsoralen. However, compounds 2-4 showed no inhibition against any of the restriction enzymes.