Calorimetry, as a technique for thermal analysis, has a wide range of applications which are not only limited to studying the thermal characterisation (e.g. melting temperature, denaturation temperature and enthalpy change) of small and large drug molecules, but are also extended to characterisation of fuel, metals and oils.
A rigorous understanding of any biological system that undergoes some
change requires quantiﬁcation of its thermodynamic and kinetic properties.
Combined with structural detail, these data can be assimilated to enable a
picture of the mechanism of the change (for example, going from the free to
bound state in a biomolecular interaction, or from the folded to the unfolded
state of a biomolecule). Isothermal titration calorimetry (ITC) and diﬀerential
scanning calorimetry (DSC) provide the thermodynamic data required for
developing this understanding.
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.
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....
Although allostery plays a central role in driving protein–DNA interac-tions, the physical basis of such cooperative behavior remains poorly
understood. In the present study, using isothermal titration calorimetry in
conjunction with site-directed mutagenesis, we provide evidence that an
intricate network of energetically-coupled residues within the basic regions
of the Jun-Fos heterodimeric transcription factor accounts for its allosteric
binding to DNA.
This study examines the characteristics of binding of berberine to the
human telomeric d[AG3(T2AG3
)3] quadruplex. By employing UV-visible
spectroscopy, fluorescence spectroscopy and isothermal titration calorime-try, we found that the binding affinity of berberine to the human telomeric
quadruplex is 10
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.
Observations of thioredoxin inhibition by cadmium and
of a positive role for thioredoxin in protection from Cd
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
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.
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.
Substrate binding of a family GH19 chitinase from a moss species,
Bryum coronatum(BcChi-A, 22 kDa), which is smaller than the 26 kDa
family GH19 barley chitinase due to the lack of several loop regions (‘loop-less’), was investigated by oligosaccharide digestion, thermal unfolding
experiments and isothermal titration calorimetry (ITC).
The E3 ubiquitin ligase CHIP (C-terminus of Hsc70-interacting protein) is
believed to be a central player in the cellular triage decision, as it links the
molecular chaperones Hsp70⁄Hsc70 and Hsp90 to the ubiquitin proteaso-mal degradation pathway. To better understand the decision process, we
determined the affinity of CHIP for Hsp70 and Hsp90 using isothermal
The enzymes pyruvate decarboxylase (E1) and dihydro-lipoyl dehydrogenase (E3) bind tightly but in a mutually
exclusive manner to the peripheral subunit-binding domain
(PSBD) of dihydrolipoyl acetyltransferase in the pyruvate
dehydrogenase multienzyme complex of Bacillus stearo-thermophilus.