Articolo in rivista, 2002, ENG, 10.1016/j.bpc.2011.07.008

Effect of heavy water on protein flexibility

Cioni, P; Strambini, GB

Istituto di Biofisica-CNR

The effects of heavy water (D2O) on internal dynamics of proteins were assessed by both the intrinsic phosphorescence lifetime of deeply buried Trp residues, which reports on the local structure about the triplet probe, and the bimolecular acrylamide phosphorescence quenching rate constant that is a measure of the average acrylamide diffusion coefficient through the macromolecule. The results obtained with several protein systems (ribonuclease T1, superoxide dismutase, beta-lactoglobulin, liver alcohol dehydrogenase, alkaline phosphatase, and apo- and Cd-azurin) demonstrate that in most cases D2O does significantly increase the rigidity the native structure. With the exception of alkaline phosphatase, the kinetics of the structure tightening effect of deuteration are rapid compared with the rate of H/D exchange of internal protons, which would then assign the dampening of structural fluctuations in D2O to a solvent effect, rather than to stronger intramolecular D bonding. Structure tightening by heavy water is generally amplified at higher temperatures, supporting a mostly hydrophobic nature of the underlying interaction, and under conditions that destabilize the globular fold.

Biophysical journal (Print) 82 (6), pp. 3246–3253

Keywords

p53-tumor suppressor protein, Protein flexibility, Tryptophan phosphorescence, Acrylamide quenching, MDM2

CNR authors

Strambini Giovanni Battista, Cioni Patrizia

CNR institutes

ID: 349590

Year: 2002

Type: Articolo in rivista

Creation: 2016-03-04 11:41:56.000

Last update: 2016-03-04 11:41:56.000

External links

OAI-PMH: Dublin Core

OAI-PMH: Mods

OAI-PMH: RDF

DOI: 10.1016/j.bpc.2011.07.008

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:349590

DOI: 10.1016/j.bpc.2011.07.008

ISI Web of Science (WOS): 000295953100007

ISI Web of Science (WOS): 000175802700042