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|Title:||Long-lived states induced by extended illumination of carbonmonoxy-myoglobin|
|Author(s):||Sauke, Todd Bennet|
|Doctoral Committee Chair(s):||Frauenfelder, Hans|
|Department / Program:||Physics|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Myoglobin is a heme-protein that binds small ligands, such as O$\sb2$ and CO. A photon of visible light absorbed by the protein can break the protein ligand bond. At low temperatures ($>$160K) the kinetics of recombination of photodissociated carbonmonoxy-myoglobin are non-exponential, having amplitude components that extend over many orders of magnitude in time. The bound and unbound states of the system have different spectroscopic signatures and the kinetics of recombination can be measured by monitoring the time dependence of the absorption spectrum of the sample after photodissociation.
After a period of intense illumination with light, the recombination kinetics slow down. The proteins are "pumped" to longer lived states. After waiting, the system resets, such that a photodissociation initiates regular, non-pumped, kinetics. I have measured the kinetics of the "pumped" states and the time course of the resetting, at various temperatures. Physical models, including connections to glass theories, are considered, and thermodynamic parameters for the various processes involved have been determined.
|Rights Information:||Copyright 1989 Sauke, Todd Bennet|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI8924937|