Premium
Temperature‐dependent structural and functional features of a hyperthermostable enzyme using elastic neutron scattering
Author(s) -
Koutsopoulos Sotirios,
van der Oost John,
Norde Willem
Publication year - 2005
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.20606
Subject(s) - pyrococcus furiosus , chemistry , anharmonicity , intramolecular force , neutron scattering , crystallography , denaturation (fissile materials) , molecular dynamics , scattering , computational chemistry , stereochemistry , biochemistry , condensed matter physics , physics , nuclear chemistry , optics , archaea , gene
The dynamic behavior of an endoglucanase from the hyperthermophilic microorganism Pyrococcus furiosus was investigated using elastic neutron scattering. The temperature dependence of the atomic motions was correlated with conformational and functional characteristics of the enzyme. The onset of biological function at temperatures higher than approximately 25°C (the hyperthermostable enzyme is essentially inactive at room temperature) was associated with a dynamical transition in the anharmonic motions domain. This transition from the nonactive to the enzymatically active conformation involved structurally similar conformational substates in the energy landscape. From the mean‐square displacement of the protein atoms, the molecular flexibility and the effective force constants were calculated at different temperature zones. The results showed that the activity increases at higher temperatures where the intramolecular bonds are weakened and the overall rigidity of the protein is decreased. Further temperature increase resulted in significantly increased atomic fluctuations featuring heat denaturation of the protein. Proteins 2005. © 2005 Wiley‐Liss, Inc.