1,721,043 research outputs found
Ala160 and His116 residues are involved in activity and specificity of apyrase, an ATP-hydrolysing enzyme produced by enteroinvasive Escherichia coli
No full textThe virulence plasmid-carried apy (phoN2) gene of Shigella and related enteroinvasive
Escherichia coli (EIEC) encodes apyrase, an ATP-diphosphohydrolase belonging to class A
of the non-specific acid phosphatases (A-NSAPs). Apyrase and A-NSAPs share three domains
of conserved amino acids (domains D1–D3) containing residues forming the putative active site of
apyrase. In spite of their similarity, apyrase and A-NSAPs show different substrate specificity,
apyrase being able to hydrolyse nucleotide tri- and diphosphates, but not monophosphates, as
well as p-nitrophenyl phosphate (pNPP), while A-NSAPs are also active towards monophosphates
and pNPP. In this paper, to get further insights into the structure–function relationship of apyrase, a
random and site-directed mutagenesis of the apy gene of EIEC strain HN280 was conducted.
Results indicate that amino acids located within the D2 and D3 conserved domains (Ser157 and
Arg192, respectively) as well as residues located in the N-terminal (Ser97) and C-terminal
(Glu233) domains are required for enzyme activity. Surprisingly, Ala160, located near the D2
domain and considered to be important for enzyme specificity, is required for enzyme activity, as its
substitution with Thr led to the inactivation of enzyme activity. Furthermore, residue His116 is
involved in apyrase specificity, since the H116L apyrase mutant shows substrate specificity
resembling that of A-NSAPs
Human serum proteome analysis: new source of markers in metabolic disorders.
No full textThe prevalence of metabolic disorders (MDs), especially diabetes, is rapidly increasing worldwide, leading to an increasing risk of cardiovascular and other socially relevant complications. To boost MD biomarker discovery, advanced proteomics can harmonize metabolomics. Indeed, the rapid development of mass spectrometry (MS) has designated proteomics as an emerging platform to interrogate the plasma/serum proteome for the discovery of next-generation biomarkers exploitable for risk assessment, early detection and prognosis of MDs. Preanalytical plasma/serum treatment, such as combinatorial peptide ligand libraries with nano-liquid chromatography coupled with tandem MS or selected reaction monitoring coupled to triple-quadrupole time-of-flight instruments, are proven clinical laboratory techniques for quantitative analyses. New strategies, such as SWATH (TM) MS, which allows us to systematically characterize and quantify query sample sets of 'any protein of interest' in complex biological samples, may dramatically improve next-generation MD biomarkers, especially considering the plethora of candidates coming from the 'bioreactor' gut microbiota affecting MD onset and progressio
Design of a bioinformatics algorithm for the assessment of mouse gut phylotypes identified by metaproteomic approach
No full textThe impact of intestinal microbiota on weight loss in Parkinson's disease patients: A pilot study
No full textBackground: There is increasing evidence of the association between microbiome dysfunction and Parkinson's disease (PD). Moreover, some PD patients suffer from unintentional weight loss (WL) which may precede the motor manifestations of the disease. Materials & methods: Gut microbiota profiling by 16S rRNA gene sequencing was performed in PD patients with an unintended WL, in steady weight patients (non-WL [NWL]) and in matched normal subjects. KEGG functional predictions were carried out. Results: Microbiota profiles revealed a dissimilarity between WL and NWL. Moreover, WL pathways were characterized by fatty acid biosynthesis, while NWL by inflammation pathways. Conclusion: The gut microbiota could participate in weight alteration observed in PD by the presence of bacteria involved in weight gain and inflammation, or conversely by bacteria implicated in energy expenditure
Integration of datasets from different analytical techniques to assess the impact of nutrition on human metabolome.
Full text linkBacteria colonizing the human intestinal tract exhibit a high phylogenetic diversity that reflects their immense metabolic potentials. The catalytic activity of gut microbes has an important impact on gastrointestinal (GI) functions and host health. The microbial conversion of carbohydrates and other food components leads to the formation of a large number of compounds that affect the host metabolome and have beneficial or adverse
effects on human health. Metabolomics is a metabolic-biology system approach focused on the metabolic responses understanding of living systems to physio-pathological stimuli by using multivariate statistical data on human body fluids obtained by different instrumental techniques. A metabolomic approach based on an analytical platform could be able to separate, detect, characterize and quantify a wide range of metabolites
and its metabolic pathways. This approach has been recently applied to study the metabolic changes triggered in the gut microbiota by specific diet components and diet variations, specific diseases, probiotic and synbiotic food intake. This review describes the metabolomic data obtained by analyzing human fluids by using different techniques and particularly Gas Chromatography Mass Spectrometry Solid-phase Micro Extraction (GC-MS/SPME), Proton Nuclear Magnetic Resonance (1H-NMR) Spectroscopy and Fourier Transform Infrared (FTIR) Spectroscopy. This instrumental approach has a good potential in the identification and detection of specific food intake and diseases biomarker
The pediatric gut bacteriome and virome in response to SARS-CoV-2 infection
Full text linkIntroduction since the beginning of the SARS-CoV-2 pandemic in early 2020, it has been apparent that children were partially protected from both infection and the more severe forms of the disease. many different mechanisms have been proposed to explain this phenomenon, including children's frequent exposure to other upper respiratory infections and vaccines, and which inflammatory cytokines they are more likely to produce in response to infection. furthermore, given the presence of SARS-CoV-2 in the intestine and its ability to infect enterocytes, combined with the well described immunomodulatory capabilities of the microbiome, another potential contributing factor may be the presence of certain protective microbial members of the gut microbiota (GM). methods we performed shotgun metagenomic sequencing and profiled both the bacteriome and virome of the GM of pediatric SARS-CoV-2 patients compared to healthy, age-matched subjects. results we found that, while pediatric patients do share some pro-inflammatory microbial signatures with adult patients, they also possess a distinct microbial signature of protective bacteria previously found to be negatively correlated with SARS-CoV-2 infectivity and COVID-19 severity. COVID-19 was also associated with higher fecal cytomegalovirus load, and with shifts in the relative abundances of bacteriophages in the GM. furthermore, we address how the preventative treatment of COVID-19 patients with antibiotics, a common practice especially in the early days of the pandemic, affected the bacteriome and virome, as well as the abundances of antimicrobial resistance and virulence genes in these patients. discussion to our knowledge, this is the first study to address the bacteriome, virome, and resistome of pediatric patients in response to COVID-19 and to preventative antibiotics use
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