Search results for " enzyme"
showing 10 items of 791 documents
Disassembling Papaver: a restriction site analysis of chloroplast DNA
1992
The results from a chloroplast DNA restriction site analysis of the genera Papaver and Roemeria of subf. Papaveroideae (Papaveraceae) and five outgroup taxa are presented. Papaver is represented by 14 species of eight of the 11 sections recognized, Roemeria by two of its three species. Hunnemannia fumariifolia (subf. Eschscholzioideae), Chelidonium majus (subf. Chelidonioideae), Romneya coulteri, Argemone munita and Stylomecon heterophyllum (all subf. Papaveroideae) were chosen as outgroups. DNAs were digested with 24 restriction enzymes. The major results from this analysis are: 1. Papaver, Roemeria and Stylomecon form a monophyletic group supported by at least 17 restriction site mutation…
Effects of garlic powders with varying alliin contents on hepatic drug metabolizing enzymes in rats
2003
International audience; The anticarcinogenic effect of garlic has been demonstrated in both epidemiologic and experimental studies. In this study, possible mechanisms involved in the anticarcinogenic effect of garlic consumption were assessed by determining its capacity to alter drug metabolizing enzymes, in relation with its alliin content. Rats were fed a diet for 2 weeks containing 5% garlic powders produced from bulbs grown on soils with different levels of sulfate fertilization and therefore containing differing amounts of alliin. Activities of several hepatic enzymes, which are important in carcinogen metabolism such cytochromes P450 (CYP) and phase II enzymes, were determined. Garlic…
Sensitivity of three commercial tests for SARS-CoV-2 serology in children: an Italian multicentre prospective study
2022
Abstract Background US Food and Drug Administration has issued Emergency Use Authorizations for hundreds of serological assays to support Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) diagnosis. The aim of this study is to evaluate, for the first time in children, the performance of three widely utilized SARS-CoV-2 serology commercial assays, Diesse Diagnostics (IgG, IgA, IgM) and Roche Diagnostics, both Roche Nucleocapsid (N) IgG and Roche Spike (S) IgG assays. Methods Sensitivity and 95% confidence intervals (CIs) were estimated for each of the three different serological tests and mixed and direct comparison were performed. Univariate and multivariate Poisson regression mo…
Expression of yeast but not human apurinic/apyrimidinic endonuclease renders Chinese hamster cells more resistant to DNA damaging agents.
1997
Abasic sites represent ubiquitous DNA lesions that arise spontaneously or are induced by DNA-damaging agents. They block DNA replication and are considered to be cytotoxic and mutagenic. The key enzymes involved in the repair of abasic sites are apurinic/apyrimidinic (AP) endonucleases which process these lesions in an error-free mechanism. To analyze the role of AP endonuclease in the protection of mammalian cells against DNA damaging agents, we have transfected both the human (APE) and the yeast (APN1) AP endonuclease in Chinese hamster cells and compared the effects of expression of these genes in stable transfectants as to survival of cells and formation of chromosomal aberrations. Alth…
Effects of yeast proteolytic activity on Oenococcus oeni and malolactic fermentation
2006
International audience; Alcoholic fermentation of synthetic must was performed using either Saccharomyces cerevisiae or a mutant Delta pep4, which is deleted for the proteinase A gene. Fermentation with the mutant Delta pep4 resulted in 61% lower levels of free amino acids, and in 62% lower peptide concentrations at the end of alcoholic fermentation than in the control. Qualitative differences in amino acid composition were observed. Changes observed in amino acids in peptides were mainly quantitative. After alcoholic fermentation each medium was inoculated with Oenococcus oeni. Malolactic fermentation in the medium with the Delta pep4 strain took 10 days longer than the control. This diffe…
Evaluation of the genotoxic and cytochrome P450 monooxygenase‐inhibitory potential of dicuran on procaryotic and eucaryotic test systems
2000
The effect of the herbicide Dicuran 500 FL (formulated product) on the phenotypical and genotypical changes in procaryotic and eucaryotic organisms was investigated using short-term tests for detecting genotoxins. Since pesticides discharged in the water environment can modulate the mixed-function monooxygenases (MFO) detoxification system of water organisms, the in vivo and in vitro effects of Dicuran on hepatic cytochrome P450 (cyt P450) monooxygenase activities were also examined in juvenile carp (Cyprinus carpio L.). By measuring the activities of MFO in experimental carp exposed to Dicuran an attempt was made to establish whether Dicuran could be bioactivated by MFO into ultimate mutag…
Carbohydrate-Mediated Biomolecular Recognition and Gating of Synthetic Ion Channels
2013
Nanochannel-based biosensing devices have been proposed for selective detection of protein analyte molecules. However, the design and miniaturization of reusable channel-based biosensors is still a challenge in nanoscience and biotechnology. We present here a reusable nanofluidic biosensor based on reversible lectin-carbohydrate interactions. The nanochannels are fabricated in heavy ion tracked polymer membranes. The channel walls are functionalized with p-aminophenyl alpha-D-mannopyranoside (APMP) monolayers through carbodiimide coupling chemistry. The chemical (mannopyranoside) groups on the inner channel walls serve as binding sites and interact with specific protein molecules. The bindi…
ABO genotyping by PCR-RFLP and cloning and sequencing
2005
A refined PCR-RFLP based method was established to genotype ABO blood groups. The main objective of this study was to make the techniques also suitable for working with degraded DNA. Specific primer design was carried out to choose fragments shorter than 200 bp as necessary in forensic and archaeological applications. Four fragments of exon 6 and 7 of the ABO gene were amplified and digested by in total 7 restriction endonucleases. Particular attention was paid to the base changes at nucleotide positions 261(delG), 297, 526, 703, 721, 771, 796 and 1060(delC) in order to distinguish the six common alleles A101, A201, B, O01, O02 and O03. Furthermore, this method also enables determination of…
Genetic organization of the mle locus and identification of a mleR-like gene from Leuconostoc oenos
1996
Characterization of the mle locus harboring the malolactic enzyme gene mleA and malate permease gene mleP from Leuconostoc oenos was completed in this study by mRNA analysis. Northern (RNA) blot experiments revealed a 2.6-kb transcript, suggesting an operon structure harboring mleA and mleP genes. Primer extension analysis showed that the mle operon has a single transcription start site located 17 nucleotides upstream of the ATG translation start site for the mleA gene. We found sequences, TTGACT and TATGAT (which are separated by 18 bp), that are closely related to the gram-positive and Escherichia coli consensus promoter sequences. Upstream of the mleA gene, an 894-bp open reading frame t…