TY  - JOUR
A1  - Lilie, Hauke
A1  - Bär, Dorit
A1  - Kettner, Karina
A1  - Weininger, Ulrich
A1  - Balbach, Jochen
A1  - Naumann, Manfred
A1  - Müller, Eva-Christina
A1  - Otto, Albrecht
A1  - Gast, Klaus
A1  - Golbik, Ralph
T1  - Yeast hexokinase isoenzyme ScHxk2 : stability of a two-domain protein with discontinuous domains
N2  - The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional 1H NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about ;G = ;22 kJ mol;1.
Y1  - 2011
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/32299
UR  - http://peds.oxfordjournals.org/content/24/1-2/79.long
SN  - 0269-2139
ER  -