Protein Under Pressure: Molecular Dynamics Simulation of the Arc Repressor
Experimental nuclear magnetic resonance results for the Arc Repressor have shown that this dimeric protein dissociates into a molten globule at high pressure. This structural change is accompanied by a modification of the hydrogenbonding pattern of the intermolecular -sheet: it changes its character from intermolecular to intramolecular with respect to the two monomers. Molecular dynamics simulations of the Arc Repressor, as a monomer and a dimer, at elevated pressure have been performed with the aim to study this hypothesis and to identify the major structural and dynamical changes of the protein under such conditions. The monomer appears less stable than the dimer. However, the complete dissociation has not been seen because of the long timescale needed to observe this phenomenon. In fact, the protein structure altered very little when increasing the pressure. It became slightly compressed and the dynamics of the side-chains and the unfolding process slowed down. Increasing both, temperature and pressure, a tendency of conversion of intermolecular into intramolecular hydrogen bonds in the -sheet region has been detected, supporting the mentioned hypothesis. Also, the onset of denaturation of the separated chains was observed.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 920552
- Report Number(s):
- PNNL-SA-51875; TRN: US200818%%702
- Journal Information:
- Proteins. Structure, Function, and Bioinformatics, 65(1):136-144, Vol. 65, Issue 1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geometry of the antitumor drug ditercalinium bisintercalated into d(CpGpCpG)/sub 2/ by /sup 1/H NMR
Transition between protein-like and polymer-like dynamic behavior: Internal friction in unfolded apomyoglobin depends on denaturing conditions