695 research outputs found
Giusti L, Baldini C, Bazzichi L, Ciregia F, Tonazzini I, Mascia G, Giannaccini G, Bombardieri S, Lucacchini A
No full textAdenosine deaminase.
No full textAdenosine deaminase plays a key role in adenosine metabolism. This nueleoside has some important pharmacological and toxic effects. An adenosine deaminase deficiency observed in some cases of severe congenital immunodeficiency represents the first link between an immunological and enzymic defect. Adenosine deaminase from calf intestinal mucosa, the most widely studied enzyme, hydrolytically deaminates, in addition to adenosine, some other natural and synthetic nucleosides and also dehalogenates 6-halopurine ribosides. Many studies have been carried out to define the contribution of purine and ribose moieties in the binding of substrate and to help prepare effective inhibitors of the enzyme. This chapter examines the synthesis of 9-(p-Bromoacetamidobenzyl) adenine, inactivation of enzyme and stoichiometry of reaction, identification of alkylated amino acid residues, and kinetics of the reaction
AFFINITY LABELING OF ADENOSINE-A1 BINDING-SITES
No full textAbstract
The adenosine A1 receptors of sheep brain membranes have been identified by the specific binding of radiolabeled cyclohexyl[3H]adenosine ([3H]CHA). Pretreatment of membranes with periodate-oxidized CHA causes a dose- and time-dependent decrease in the number of binding sites. No decrease occurs when membranes are pretreated with CHA. Binding of [3H]CHA to the remaining sites occurs with the same characteristics as binding to the untreated receptor population
137Caesium in samples of wild-grown Boletus edulis Bull. from Lucca province (Tuscany, Italy) and other Italian and European geographical areas
No full textSamples of the edible mushroom Boletus edulis Bull. were studied to assess the risk for human health related to their content of the artificial radionuclide 137Cs. Fresh B. edulis carpophores were collected in four undeveloped microhabitats of Lucca province (Tuscany, North-Central Italy). Dried non-cultivated samples coming from this same district and 11 other Italian provinces or European countries were instead purchased fromcommercial sources. Contents of 137Cs, reported as Bq kg‒1 dry weight (dw), were measured by γ-spectrometry. The radionuclide concentration varied depending on the gathering site in fresh samples, with 41.8 ± 5.2 Bq kg‒1 dw at site 1 (Tosco-Emiliani Apennine) and four-fold less, 12.8 ± 1.3 Bq kg‒1 dw, at site 2 (Apuan Alps). Moreover, fresh or dried carpophores from Lucca province displayed among the lowest 137Cs contents in Europe. Average 137Cs levels in all analysed samples were substantially below the legal threshold for edible mushrooms, 600 Bq kg‒1 dw. Conclusively, we report that 137Cs amounts in B. edulis depend on both the distance from the Chernobyl accident and multifactorial features of collection sites. We also show that the consumption of European B. edulis does not represent a major health risk with respect to 137Cs radio contamination
Stabilization of the T-state of ferrous human adult haemoglobin by chlorpromazine and trifluoperazine
No full textEVIDENCE FOR THE EXISTENCE OF A SPECIFIC BINDING-SITE FOR INDOMETHACIN ON BOVINE VESICULAR GLAND MICROSOMES
No full textUsing bovine vesicular gland microsomes and [14C]indomethacin we demonstrated the presence of a specific binding site for nonsteroidal anti-inflammatory drugs. Specific binding of [14C]indomethacin to microsomes was rapid, with most of the ligand bound by 2 min at 4 degrees C. In routine binding assays the incubation temperature was maintained at 4 degrees C, because the maximal specific binding was obtained. Specific [14C]indomethacin binding appeared to increase linearly with increasing protein concentration over the range of 0.1-1.0 mg of microsomal protein. Specific binding was saturable and Scatchard analysis of binding data showed a single class of binding sites with a dissociation constant (Kd) of 3.8 microM and a maximal number of binding sites (Bmax) of about 1272 pmol/mg of protein. When these binding data were plotted according to the Hill equation, a straight line was obtained with a Hill coefficient of 1.0. Structural specificity of the nonsteroidal anti-inflammatory drug site was studied with diclofenac, arylpropionic acids (ketoprofen and indoprofen), and aspirin. Diclofenac and arylpropionic derivatives were able to compete with [14C]indomethacin for binding to microsomes, while aspirin was a weak inhibitor
Proteomic studies of formalin-fixed paraffin-embedded tissues
No full textFormalin-fixed paraffin-embedded (FFPE) tissue specimens represent a valuable informational resource of histologically characterized specimens for proteomic studies. In this article, the authors review the advancement performed in the field of FFPE proteomics focusing on formaldehyde treatment and on strategies addressed to obtain the best recovery in the protein/peptide extraction. A variety of approaches have been used to characterize protein tissue extracts, and many efforts have been performed demonstrating the comparability between fresh/frozen and FFPE proteomes. Finally, the authors report and discuss the large numbers of works aimed at developing new strategies and sophisticated platforms in the analysis of FFPE samples to validate known potential biomarkers and to discover new ones
BIOCHEMICAL AND PHARMACOLOGICAL CHARACTERIZATION OF PERIODATE-OXIDIZED ADENOSINE-ANALOGS AT ADENOSINE A(1) RECEPTORS
No full textPeriodate oxidation of eight N-6-substituted adenosine derivatives was performed with the aim of oxidizing the vicinal 2' and 3' hydroxyl groups of the ribose moiety. A thermodynamical and pharmacological characterization of the products of this transformation allowed us to verify that oxidized adenosine analogues act as agonists at adenosine A(1) receptors. The dependence of their association constants on temperature indicates that their binding is entropy driven, a feature typical of adenosine A1( )receptor agonists; moreover all synthesized compounds were able to fully inhibit the forskolin induced c-AMP accumulation in rat isolated adipocytes. This is the first report suggesting that the presence of an intact ribose moiety is not necessary for agonistic activity at adenosine A(1) receptor. In fact periodate oxidation of the ribose moiety yields a dialdehyde and it is recognized that nucleoside dialdehydes are complex equilibrium mixtures of cyclic and acyclic hydrates and hemiacetals
Proteomics insight into psychiatric disorders: an update on biological fluid biomarkers
No full textIntroduction: Psychiatric disorders are severe, debilitating and heterogeneous diseases with a high impact on public health. In this review we address state of the art clinical approaches to diagnose psychiatric disorders and underline the necessity to found new tools to help clinicians. Areas covered: We provide an update on proteomic studies and suggest potential biomarkers focusing on schizophrenia (SCZ), bipolar disorder (BD), and major depression (MD). In particular, we direct our attention to proteomic results obtained from studies on biological fluids. We also show an interaction analysis of differentially expressed proteins found in SCZ, BD and MD. Expert commentary: To date, there is a need to find molecular biomarkers for psychiatric disorders. The use of a proteomic approach allows protein fingerprints to be defined in normal and pathological states. We believe that saliva is an intriguing biological fluid, whose proteomic study in psychiatric disorders is still in its early stages
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