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.
3-Phosphoglycerate kinase (PGK) is a typical two-domain hinge-bending
enzyme with a well-structured interdomain region. The mechanism of
domain–domain interaction and its regulation by substrate binding is not
yet fully understood. Here the existence of strong cooperativity between
the two domains was demonstrated by following heat transitions of pig
muscle and yeast PGKs using differential scanning microcalorimetry and
Microcalorimetry and UV-vis spectroscopy were used to conduct thermodynamic and kinetic investigations of the scission of calf thymus DNA catalyzed by bleomycin A5 (BLM-A5) in the presence of ferrous ion and oxygen. The molar reaction enthalpy for the cleavage, the Michaelis– Menten constant for calf thymus DNA and the turnover number of BLM-A5 were calculated by a novel thermokinetic method for an enzyme-catalyzed reaction to be )577 ± 19 kJÆmol)1, 20.4 ± 3.8 lM and 2.28 ± 0.49 · 10)2 s)1, respectively, at 37.0 °C. This DNA cleavage was a largely exothermic reaction....
Staphylococcalnuclease is a single domain protein with 149 amino acids. It
has no disulfide bonds, which makes it a simple model for the study of pro-tein folding. In this study, 20 mutants of this protein were generated each
with a single base substitution of glycine for negatively charged glutamic
acid or aspartic acid. Using differential scanning microcalorimetry in ther-mal denaturation experiments, we identified two mutants, E75G and
E129G, having approximately 43% and 44%, respectively, lowerDHcal
values than the wild-type protein....
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.