scholarly journals Binding of urate and caffeine to haemocyanin analysed by isothermal titration calorimetry

2001 ◽  
Vol 204 (5) ◽  
pp. 1033-1038 ◽  
Author(s):  
M. Menze ◽  
N. Hellmann ◽  
H. Decker ◽  
M. Grieshaber
Keyword(s):  
Isothermal Titration Calorimetry ◽  
Equilibrium Dialysis ◽  
Oxygen Carrier ◽  
Titration Calorimetry ◽  
Oxygen Binding ◽  
Binding Properties ◽  
Induced Changes ◽  
Insight Into ◽  
Effector Binding ◽  
Binding Behaviour

Haemocyanin serves as an oxygen carrier in the haemolymph of decapod crustaceans. The oxygen-binding behaviour of the pigment is modulated by the two major anaerobic metabolites, l-lactate and urate. The binding of these two metabolites to haemocyanin has been investigated mainly indirectly by following the effector-induced changes in the oxygen-binding properties of the respiratory pigment. Only a few direct investigations of effector binding, employing ultracentrifugation techniques and equilibrium dialysis, have been carried out. No evidence for cooperative binding for either effector was detected using these methods. However, isothermal titration calorimetry (ITC) offers a useful tool to gain additional insight into the binding of effectors to these highly allosterically regulated macromolecules. By applying the ITC method to the fully oxygenated dodecameric haemocyanin of the lobster Homarus vulgaris, cooperativity in binding has been found for the urate analogue caffeine but not for urate itself: using urate and the urate analogue caffeine as ligands, two conformations of the oxygenated pigment were detected.

scholarly journals Calorimetric techniques applied to the thermodynamic study of interactions between proteins and polysaccharides

2016 ◽  
Vol 46 (8) ◽  
pp. 1491-1497
Author(s):  
Monique Barreto Santos ◽  
Bernardo de Sá Costa ◽  
Edwin Elard Garcia Rojas
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermodynamic Parameters ◽  
Isothermal Titration Calorimetry ◽  
Thermal Energy ◽  
Titration Calorimetry ◽  
Biological Macromolecules ◽  
Valuable Insight ◽  
Scanning Calorimetry ◽  
Temperature Scanning ◽  
Insight Into

ABSTRACT: The interactions between biological macromolecules have been important for biotechnology, but further understanding is needed to maximize the utility of these interactions. Calorimetric techniques provide information regarding these interactions through the thermal energy that is produced or consumed during interactions. Notable techniques include differential scanning calorimetry, which generates a thermodynamic profile from temperature scanning, and isothermal titration calorimetry that provide the thermodynamic parameters directly related to the interaction. This review described how calorimetric techniques can be used to study interactions between proteins and polysaccharides, and provided valuable insight into the thermodynamics of their interaction.

scholarly journals Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

2015 ◽  
Vol 11 ◽  
pp. 147-154 ◽  
Author(s):  
Thorbjørn Terndrup Nielsen ◽  
Catherine Amiel ◽  
Laurent Duroux ◽  
Kim Lambertsen Larsen ◽  
Lars Wagner Städe ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Fluorescence Spectroscopy ◽  
Isothermal Titration Calorimetry ◽  
Degree Of Substitution ◽  
Titration Calorimetry ◽  
Binding Properties ◽  
High Binding ◽  
Cyclodextrin Polymers

Novel (S)-camptothecin–dextran polymers were obtained by “click” grafting of azide-modified (S)-camptothecin and alkyne-modified dextrans. Two series based on 10 kDa and 70 kDa dextrans were prepared with a degree of substitution of (S)-camptothecin between 3.1 and 10.2%. The binding properties with β-cyclodextrin and β-cyclodextrin polymers were measured by isothermal titration calorimetry and fluorescence spectroscopy, showing no binding with β-cyclodextrin but high binding with β-cyclodextrin polymers. In aqueous solution nanoparticles were formed from association between the (S)-camptothecin–dextran polymers and the β-cyclodextrin polymers.

scholarly journals A Comparative Study on Nickel Binding to Hpn-like Polypeptides from Two Helicobacter pylori Strains

2021 ◽  
Vol 22 (24) ◽  
pp. 13210
Author(s):  
Danuta Witkowska ◽  
Agnieszka Szebesczyk ◽  
Joanna Wątły ◽  
Michał Braczkowski ◽  
Magdalena Rowińska-Żyrek
Keyword(s):  
Helicobacter Pylori ◽  
Comparative Study ◽  
Potentiometric Titration ◽  
Isothermal Titration Calorimetry ◽  
Titration Calorimetry ◽  
Binding Properties ◽  
Protein Fragments ◽  
Nickel Binding ◽  
Independent Reaction

Combined potentiometric titration and isothermal titration calorimetry (ITC) methods were used to study the interactions of nickel(II) ions with the N-terminal fragments and histidine-rich fragments of Hpn-like protein from two Helicobacter pylori strains (11637 and 26695). The ITC measurements were performed at various temperatures and buffers in order to extract proton-independent reaction enthalpies of nickel binding to each of the studied protein fragments. We bring up the problem of ITC results of nickel binding to the Hpn-like protein being not always compatible with those from potentiometry and MS regarding the stoichiometry and affinity. The roles of the ATCUN motif and multiple His and Gln residues in Ni(II) binding are discussed. The results provided the possibility to compare the Ni(II) binding properties between N-terminal and histidine-rich part of Hpn-like protein and between N-terminal parts of two Hpn-like strains, which differ mainly in the number of glutamine residues.

scholarly journals Substrate binding properties of potato tuber ADP-glucose pyrophosphorylase as determined by isothermal titration calorimetry

FEBS Letters ◽  
2015 ◽  
Vol 589 (13) ◽  
pp. 1444-1449 ◽  
Author(s):  
Bilal Cakir ◽  
Aytug Tuncel ◽  
Abigail R. Green ◽  
Kaan Koper ◽  
Seon-Kap Hwang ◽  
...  
Keyword(s):  
Potato Tuber ◽  
Isothermal Titration Calorimetry ◽  
Substrate Binding ◽  
Titration Calorimetry ◽  
Binding Properties ◽  
Adp Glucose Pyrophosphorylase

Oxygen binding by single red blood cells from the red-eared turtle Trachemys scripta

2001 ◽  
Vol 90 (5) ◽  
pp. 1679-1684 ◽  
Author(s):  
Sebastian Frische ◽  
Stefano Bruno ◽  
Angela Fago ◽  
Roy E. Weber ◽  
Andrea Mozzarelli
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Oxygen Affinity ◽  
Trachemys Scripta ◽  
Oxygen Binding ◽  
Binding Properties ◽  
Cell Variation ◽  
Insight Into

Oxygen-binding properties of single red blood cells from the red-eared turtle Trachemys scripta were measured by microspectrophotometry to describe the variation in oxygen affinity of red blood cells and to gain insight into the distribution of functionally different hemoglobins among red blood cells. Methodologically, this study represents the first report on the cell-to-cell variation in oxygen-binding properties based on oxygen-binding curves of single vertebrate red blood cells. The cells differed significantly with respect to oxygen affinity. Mean oxygen pressure at half saturation of the cells in a blood sample was found to be 20.1 ± 3.3 (SD) Torr. The distribution of oxygen affinities among red blood cells is unimodal, indicating that the two hemoglobins found in turtle blood are not segregated in distinct cells. Therefore, the functional interaction shown by these hemoglobins in vitro is likely to take place in vivo. The considerable variation in oxygen affinity between individual red blood cells calls for its incorporation in models of tissue oxygenation.

Sign in / Sign up

Export Citation Format

Share Document