Terbium luminescence-lifetime heterogeneity and protein equilibrium conformational dynamics.
Year: 1987
Type: article
Abstract: The fluorescence decay of the rare earth terbium when bound to the protein calmodulin changes from a simple exponential decay to a complex nonexponential decay as the temperature is lowered below 200 K. We have fit the observed decay curves by assuming that the terbium emission is a forced electric dipole transition and proteins have a distribution of continuous conformational states. Quantitative fits to the data indicate that the root-mean-square configurational deviation of the atoms surrounding the terbium ion is 0.2 A, in good agreement with other measurements. We further point out that because the protein seems to undergo a glass transition yet retains configurational order at room temperature, the proper name for the physical state of a protein at room temperature is the rubber-like state.
Authors: R H Austin, D L Stein, J Wang
Institution: Princeton University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2043996824