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 ◽  
...  
2015 ◽  
Vol 11 ◽  
pp. 147-154 ◽  
Author(s):  
Thorbjørn Terndrup Nielsen ◽  
Catherine Amiel ◽  
Laurent Duroux ◽  
Kim Lambertsen Larsen ◽  
Lars Wagner Städe ◽  
...  

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.


2021 ◽  
Vol 22 (24) ◽  
pp. 13210
Author(s):  
Danuta Witkowska ◽  
Agnieszka Szebesczyk ◽  
Joanna Wątły ◽  
Michał Braczkowski ◽  
Magdalena Rowińska-Żyrek

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.


Biochemistry ◽  
2013 ◽  
Vol 52 (15) ◽  
pp. 2505-2507 ◽  
Author(s):  
Kathrin Schröder-Tittmann ◽  
Danilo Meyer ◽  
Johannes Arens ◽  
Cindy Wechsler ◽  
Michael Tietzel ◽  
...  

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241912
Author(s):  
Masaki Kohno ◽  
Takatoshi Arakawa ◽  
Naoki Sunagawa ◽  
Tetsuya Mori ◽  
Kiyohiko Igarashi ◽  
...  

Cyclic α-maltosyl-(1→6)-maltose (CMM) is a cyclic glucotetrasaccharide with alternating α-1,4 and α-1,6 linkages. Here, we report functional and structural analyses on CMM-binding protein (CMMBP), which is a substrate-binding protein (SBP) of an ABC importer system of the bacteria Arthrobacter globiformis. Isothermal titration calorimetry analysis revealed that CMMBP specifically bound to CMM with a Kd value of 9.6 nM. The crystal structure of CMMBP was determined at a resolution of 1.47 Å, and a panose molecule was bound in a cleft between two domains. To delineate its structural features, the crystal structure of CMMBP was compared with other SBPs specific for carbohydrates, such as cyclic α-nigerosyl-(1→6)-nigerose and cyclodextrins. These results indicate that A. globiformis has a unique metabolic pathway specialized for CMM.


2001 ◽  
Vol 204 (5) ◽  
pp. 1033-1038 ◽  
Author(s):  
M. Menze ◽  
N. Hellmann ◽  
H. Decker ◽  
M. Grieshaber

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.


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