Calorimetry

This project investigates the use of free radical initiators in the recycling of post consumer recycled high density polyethylene using reactive extrusion. Both molecular and rheological characterisation of recycled and reprocessed materials was carried out and this was followed by tensile testing of the modified materials to satisfy end use applications such as packaging and drainage piping.

154p runthenight07 01-03-2023 6 3   Download

In this paper, the thermal properties of GFRP, CFRP, and Carbon and Glass fibers reinforced epoxy hybrid composite will be studied. The composites using are all unidirectional.

12p lucastanguyen 01-06-2020 16 4   Download

Guanosine triphosphate nucleotide analogues such as GppNHp (also named GMPPNP) or GTPcS are widely used to stabilize rapidly hydrolyzing protein-nucleotide complexes and to investigate biochemical reaction pathways. Here we describe the chemical synthesis of guanosine 5¢-O-(c-amidotriphosphate) (GTPcNH2) and a new synthesis of guanosine 5¢-O-(c-fluorotriphosphate) (GTPcF). The two nucleotides were characterized using NMR spectroscopy and isothermal titration calorimetry. Chemical shift data on 31P, 19F and 1H NMR resonances are tabulated.

9p system191 01-06-2013 32 5   Download

Division of Medicinal and Natural Products Chemistry, Department of Chemistry and Department of Chemical Engineering, University of Iowa, USA; 2Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark Synthetic peptides based on amino-acid residues 27–38 of human serum amyloid P component represent a novel type of heparin binders as they do not contain clusters of basic amino acids or other known features associated with protein or peptide heparin binding.

8p system191 01-06-2013 54 4   Download

Fibritin is a segmented coiled-coil homotrimer of the 486-residue product of phage T4 gene wac. This protein attaches to a phage particle by the N-terminal region and ˚ forms fibrous whiskers of 530 A, which perform a chaperone function during virus assembly. The short C-terminal region has a b-annulus-like structure. We engineered a set of fibritin deletion mutants sequentially truncated from the N-termini, and the mutants were studied by differential scanning calorimetry (DSC) and CD measurements....

9p research12 01-06-2013 42 3   Download

The thermal stabilityofperoxidase fromleavesof theAfrican oil palm treeElaeis guineensis(AOPTP) at pH 3.0 was studied by differential scanning calorimetry (DSC), intrinsic fluorescence, CD and enzymatic assays.The spectral parameters asmonitoredby ellipticity changes in the far-UV CD spectrum of the enzyme as well as the increase in tryp-tophan intensity emission upon heating, together with changes in enzymatic activity with temperature were seen to be good complements to the highly sensitive but integral methodofDSC....

7p research12 29-04-2013 45 3   Download

The thermal denaturation of streptokinase fromStrepto-coccus equisimilis(SK) together with that of a set of frag-ments encompassing each of its three domains has been investigated using differential scanning calorimetry (DSC). Analysis of the effects of pH, sample concentration and heating rates on the DSC thermograms has allowed us to find conditions where thermal unfolding occurs unequivo-callyunder equilibrium.

13p research12 23-04-2013 36 3   Download

The thermal unfoldingofmyosinsubfragment 1 (S1) cleaved by trypsin was studied by differential scanning calorimetry. In the absence of nucleotides, trypsin splits the S1 heavy chain into three fragments (25, 50, and 20 kDa). This cleavage has no appreciable influence on the thermal unfolding of S1 examined in the presence of ADP, in the ternary complexes of S1 with ADP and phosphate analogs, such as orthovanadate (Vi) or berylliumfluoride (BeFx), and in the presence of F-actin.

11p tumor12 22-04-2013 34 3   Download

The structure–activity relations of a series of synthetic phenoxazone drugs with aminoalkyl side chains of variable length and different terminal groups were investigated by examining their biological activity and DNA complexation affinity. Biological activitywas determined fromtheir ability to induce apoptosis and cell cycle perturbations (activation of cell cycle checkpoints) using the human malignant MOLT-3 cell line. The thermodynamic parameters of drug– DNA complexation were determined by differential scan-ning calorimetry....

8p tumor12 20-04-2013 37 4   Download

Heteronuclear high-resolution NMR spectroscopy was employed to determine the solution structure of the excisi-onase protein (Xis)from thek-like bacteriophage HK022 and to study its sequence-specificDNA interaction. Aswild-typeXiswas previously characterizedas a generallyunstable protein, abiologicallyactiveHK022Xismutantwithasingle amino acid substitutionCys28fiSerwas used in this work.

13p fptmusic 12-04-2013 45 3   Download

The heat- and pressure-induced unfolding of the glycosyl-ated and unglycosylated forms of mature carboxypeptidase Y and the precursor procarboxypeptidase Y were analysed by differential scanning calorimetry and/or by their intrinsic fluorescence in the temperature range of 20–75
Corthe pressure range of 0.1–700 MPa. Under all conditions, the precursor form showed a clear two-state transition from a folded to an unfolded state, regardless of the presence of the carbohydrate moiety.

7p fptmusic 12-04-2013 53 2   Download

Tetracycline repressor (TetR), which constitutes the most commonmechanismof bacterial resistance to an antibiotic, is a homodimeric protein composed of two identical sub-units, each of which contains a domain possessing a helix– turn–helix motif and a domain responsible for binding tetra-cycline. Binding of tetracycline in the protein pocket is accompanied by conformational changes in TetR, which abolish the specific interaction between the protein and DNA.

10p fptmusic 12-04-2013 41 1   Download

The N-terminally myristoylated, 19-amino acid peptide, corresponding to the amino terminus of the neuronal protein NAP-22 (NAP-22 peptide) is a naturally occurring peptide that had been shown by fluorescence to cause the sequestering of a Bodipy-labeled PtdIns(4,5)P2 in a cholesterol-depend-ent manner. The present work, using differential scanning calorimetry (DSC), extends the observation that formation of a PtdIns(4,5)P2-rich domain is cholesterol dependent and shows that it also leads to the forma-tion of a cholesterol-depleted domain. ...

12p awards 06-04-2013 28 2   Download

A molecular understanding of volatile anesthetic mechanisms of action will require structural descriptions of anesthetic–protein complexes. Porcine odorant binding protein is a 157 residue member of the lipocalin family that features a large b-barrel internal cavity (515 ± 30 A ˚ 3 ) lined predomin-antly by aromatic and aliphatic residues. Halothane binding to theb-barrel cavity was determined using fluorescence quenching of Trp16, and a com-petitive binding assay with 1-aminoanthracene.

0p awards 05-04-2013 18 2   Download

Thermodynamic parameters describing the conformational stability of the histidine-containing phosphocarrier protein fromStreptomyces coelicolor, scHPr, have been determined by steady-state fluorescence measurements of isothermal urea-denaturations, differential scanning calorimetry at different guanidinium hydrochloride concentrations and, independently, by far-UV circular dichroism measurements of isothermal urea-denaturations, and thermal denatura-tions at fixed urea concentrations.

17p dell39 03-04-2013 38 5   Download

Observations of thioredoxin inhibition by cadmium and of a positive role for thioredoxin in protection from Cd 2+ led us to investigate the thioredoxin–cadmium interaction properties.We used calorimetric and spectroscopicmethods at different pHvalues to explore the relative contribution of putative binding residues (Cys32, Cys35, Trp28, Trp31 and Asp26) within or near the active site. At pH 8 or 7.5 two binding sites were identified by isothermal titration calorimetry with affinity constants of 10·10 6 M )1 and 1·10 6 M )1 . ...

11p dell39 03-04-2013 39 4   Download

We used differential scanning calorimetry (DSC) and circular dichroism (CD) to investigate thermal unfolding of recombinant fibroblast isoforms ofa-tropomyosin (Tm) in comparison with that of smooth muscle Tm. These two nonmuscle Tm isoforms 5a and 5b differ internally only by exons 6b⁄6a, and they both differ from smooth muscle Tm by the N-terminal exon 1b which replaces the muscle-specific exons 1a and 2a.

13p dell39 27-03-2013 40 3   Download

The physiological phenomenon that the antisweet taste effect of gymnemic acid (GA) is diminished by application of c-cyclodextrin (c-CD) to the mouth was evaluated at the molecular level using isothermal titration calorimetry, NMR and dynamic light scattering. These analyses showed that GA specifically binds to c-CD.

7p dell39 27-03-2013 48 4   Download

hSfi1, a human centrosomal protein with homologs in other eukaryotic organisms, includes 23 repeats, each of 23 amino acids, separated by 10 residue linkers. The main molecular partner in the centrosome is a small, calcium-binding EF-hand protein, the human centrin 2. Using isothermal titration calorimetry experiments, we characterized the centrin-binding capacity of three isolated hSfi1 repeats, two exhibiting the general consen-sus motif and the third being the unique Pro-containing human repeat....

12p inspiron33 25-03-2013 36 5   Download

We show that human stefin B, a protease inhibitor from the family of cystatins, is a copper binding protein, unlike stefin A. We have used isothermal titration calorimetry to directly monitor the binding event at pH 7 and pH 5. At pH 7 stefin B shows a picomolar affinity for copper but at pH 5 the affinity is in the nanomolar range.

14p inspiron33 25-03-2013 39 5   Download