196,346 research outputs found
Primary structure of three peptides at the catalytic and allosteric sites of the fructose 1,6-bisphosphate-activated pyruvate kinase from Escherichia coli
No full textThree peptides containing 6-pyridoxyllysine have been isolated from the tryptic digest of the allosteric fructose-1,6-bisphosphate-dependent pyruvate kinase from Escherichia coli, which had been almost completely inactivated with pyridoxal 5'-phosphate. The labelled peptides have been sequenced. The comparison of their sequences with the primary structure of the cat muscle pyruvate kinase allowed to state that peptide I fits the region spanning residues 423-438 (53% identity), peptide II corresponds to residues 442-457 (44% identity) and peptide III encompasses residues 342-368 (70% identity). These findings are discussed in connection with our previous results on the involvement of the three peptides in the catalytic and regulatory properties of the enzyme (Valentini, G., Speranza, M.L., Iadarola, P., Ferri, G. & Malcovati, M. (1988) Biol. Chem. Hoppe-Seyler 369, 1219-1226) and in connection with their location in the three-dimensional structure of the cat muscle pyruvate kinase (Muirhead, H., Clayden, D.A., Lorimer, C.G., Fothergill-Gilmore, L.A., Schiltz, E. & Schmitt, W. (1986) EMBO J. 5, 475-481)
Data for: Dynorphin and Enkephalin Opioid Peptides and Transcripts in Spinal Cord During Peripheral Inflammatory Hyperalgesia and Allodynia
No full textComprehensive transcriptomic profile of human, dog and rat dorsal root ganglion tissue. Comprehensive transcriptomic profile of human and rat dorsal spinal cord tissue
Effects of exogenous amino acids on the intracellular content of proline and other amino acids in Daucus carota cells
No full textThe effect of tryptophan on the biosynthesis of proline has been investigated. Cells of Daucus carota grown in B5 medium supplemented with 5x10 - 4 M tryptophan acquired the ability to grow in the presence of inhibitory concentrations of azetidine-2-carboxylic
acid, an analog of proline. When trp was added to carrot cell cultures at sub-growth inhibiting concentrations, overproduction of intracellular free proline was observed. An increase was also observed
for lys, his, ala, leu and phe. Likewise, the addition of asparagine, glutamic acid and phenylalanine to the medium stimulated the intracellular increase of free proline and other amino acids
Desmosine, a biomarker for COPD: old and in the way..
No full textthe role of desmosines as biomarkers of chronic obstructive pulmonary disease
#rescatemineros: global media events in the microblogging age
No full textContemporary media events are experienced within the complex scenario of convergence media. Broadcasting channels and traditional mass media coexist with online digital news channels and with countless social media services. This paper describes how a global media event (the rescue operation of the 33 Chilean miners trapped underground for 69 days between August and October 2010) can be observed through the communication occurred inside Twitter, the largest microblogging platform. The article proposes a data-driven methodology that, starting from a large data acquisition procedure, is used to investigate: a) what communication patterns emerged within the microblogging sites; and b) how relevant information is propagated through the microblogging network of users
Chloroplast glyceraldehyde-3-phosphate dehydrogenase (NADP+). Reactivity of essential cysteine residues in holo- and apoenzyme.
No full textNo abstract availabl
Protein networks in induced sputum from smokers and COPD patients.
No full textRATIONALE:
Subtypes of cigarette smoke-induced disease affect different lung structures and may have distinct pathophysiological mechanisms.
OBJECTIVE:
To determine if proteomic classification of the cellular and vascular origins of sputum proteins can characterize these mechanisms and phenotypes.
SUBJECTS AND METHODS:
Individual sputum specimens from lifelong nonsmokers (n=7) and smokers with normal lung function (n=13), mucous hypersecretion with normal lung function (n=11), obstructed airflow without emphysema (n=15), and obstruction plus emphysema (n=10) were assessed with mass spectrometry. Data reduction, logarithmic transformation of spectral counts, and Cytoscape network-interaction analysis were performed. The original 203 proteins were reduced to the most informative 50. Sources were secretory dimeric IgA, submucosal gland serous and mucous cells, goblet and other epithelial cells, and vascular permeability.
RESULTS:
Epithelial proteins discriminated nonsmokers from smokers. Mucin 5AC was elevated in healthy smokers and chronic bronchitis, suggesting a continuum with the severity of hypersecretion determined by mechanisms of goblet-cell hyperplasia. Obstructed airflow was correlated with glandular proteins and lower levels of Ig joining chain compared to other groups. Emphysema subjects' sputum was unique, with high plasma proteins and components of neutrophil extracellular traps, such as histones and defensins. In contrast, defensins were correlated with epithelial proteins in all other groups. Protein-network interactions were unique to each group.
CONCLUSION:
The proteomes were interpreted as complex "biosignatures" that suggest distinct pathophysiological mechanisms for mucin 5AC hypersecretion, airflow obstruction, and inflammatory emphysema phenotypes. Proteomic phenotyping may improve genotyping studies by selecting more homogeneous study groups. Each phenotype may require its own mechanistically based diagnostic, risk-assessment, drug- and other treatment algorithms
Effects of MR889, a cyclic thiolic neutrophil elastase inhibitor, on rheologic properties of mucus.
No full textMR889 is a synthetic inhibitor of human neutrophil elastase with potential in clinical conditions characterized by a high load of this proteolytic enzyme, mainly chronic obstructive pulmonary disease. On the basis of its mechanism of inhibition, it has been suggested that MR889, upon reaction with elastase, would generate new free thiol groups. The aim of this study was to investigate whether MR889, upon reaction with elastase, may modify rheologic properties, i.e. apparent viscosity and elasticity, of both human sputum and porcine stomach mucus, in ex-vivo and in vitro experiments. MR889 10(-4) M alone had no effect on rheologic properties of samples, whereas an agent with free thiol group, n-acetylcysteine 10(-4) M reduced both viscosity and elasticity. MR889 10(-4) M upon reaction with elastase 0.03 nMol (giving 83\% of elastase inhibition) had no effect on rheologic properties of samples, whereas upon reaction with elastase 0.15 nMol (49\% inhibition) yielded a marked decrease in viscosity. This result would suggest that MR889, in the presence of a high load of elastase, may acquire direct mucus modifying capacity, likely because of its greater utilization upon reaction with the enzyme
Methods of Purification and Application Procedures of Alpha1 Antitrypsin: A Long-Lasting History.
No full textThe aim of the present report is to review the literature addressing the methods developed for the purification of alpha1-antitrypsin (AAT) from the 1950s to the present. AAT is a glycoprotein whose main function is to protect tissues from human neutrophil elastase (HNE) and other proteases released by neutrophils during an inflammatory state. The lack of this inhibitor in human serum is responsible for the onset of alpha1-antitrypsin deficiency (AATD), which is a severe genetic disorder that affects lungs in adults and for which there is currently no cure. Being used, under special circumstances, as a medical treatment of AATD in the so-called "replacement" therapy (consisting in the intravenous infusion of the missing protein), AAT is a molecule with a lot of therapeutic importance. For this reason, interest in AAT purification from human plasma or its production in a recombinant version has grown considerably in recent years. This article retraces all technological advances that allowed the manufacturers to move from a few micrograms of partially purified AAT to several grams of highly purified protein. Moreover, the chronic augmentation and maintenance therapy in individuals with emphysema due to congenital AAT deficiency (current applications in the clinical setting) is also presented
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