Electron spin-lattice relaxation in two heme iron and two blue-copper proteins at liquid helium temperatures

The relaxation rates in frozen aqueous solutions of whale ferri-myoglobin azide, bovine ferri-hemoglobin azide, cupric azurin (P. aeruginosa) and cupric spinach plastocyanin were measured at 9.5 GHz using the pulse-saturation recovery method. Measurements covered a temperature range of 1.4 K to as high as 22 K, with corresponding relaxation rates up to 10$\sp5$/sec. Improvements in the equipment and the methods of analysis have enabled more stringent tests of the temperature dependence of the rates. In particular, several models proposed in the literature to explain the anomalous temperature dependence of the Raman rates in proteins are shown to be insufficient, including two fractal models. In addition, it is shown that any model based exclusively on the protein structure fails due to the diversity of the data under various solvent conditions. A general functional form consistent with a crossover in the vibrational properties is proposed instead, similar to the localization crossover in amorphous materials.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Thayer, Bradley Denton

Contributors dc:contributor

• Stapleton, H.J.

• Chemistry, Biochemistry
• Physics, Condensed Matter
• Biophysics, General

Statement dc:rights

• Copyright 1990 Thayer, Bradley Denton

Language dc:language

eng

Identifier

AAI9114436
(UMI)AAI9114436

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20293