Comparison of the Kinetics and Spectral Properties of AuCl4- Binding by Methanobactins from Methylosinus trichosporium OB3b and Methylocystis Strain SB2: Evidence of Exciton Disruption between Intramolecular Chromophores

<p>Methanobactin (Mb) is the first characterized example of a chalkophore or copper</p> <p>binding protein. Mbs are produced by most aerobic methane oxidizing bacteria for Cu</p> <p>recruitment to the cell and eventually incorporation into the central metabolism. In addition to</p> <p>the biological purpose of Cu binding, mbs bind a number of transition and near transition metals.</p> <p>Within this text, the metal binding properties are explored and compared between two mbs,</p> <p>which represent two distinct groups of mbs, mb from Methylosinus trichosporium OB3b and mb</p> <p>from Methylocystis strain SB2. The Cu binding properties of these mbs have been previously</p> <p>explored, however, herein, the binding and displacement properties of each mb are presented for</p> <p>a number of transition metals.</p> <p>The binding properties of the metals able to displace Cu from Cu bound mb (Cu-mb) are</p> <p>of particular interest due to the extremely high affinity with which mbs bind Cu. Mercury is one</p> <p>such example, and the binding properties of Hg, in the forms Hg2+, Hg(CN)2, and CH3Hg+, are</p> <p>examined for mb from Methylocystis strain SB2. Each form was bound slightly differently by</p> <p>mb-SB2. Chapter 2 presents the characterization of the Hg binding, in each form, for mb-SB2.</p> <p>Au also displaces Cu-mb for both mb-OB3b and SB2. In the final chapter, the Au</p> <p>binding properties of mb-OB3b and mb-SB2 are compared. Previously collected CD spectra of</p> <p>mb-SB2 titrated with Au(III) suggested that an exciton transfer exists between the chromophores</p> <p>of mb-SB2. Herein, stopped flow UV-vis kinetic traces of mb-OB3b titrated with Au(III)</p> <p>demonstrate that an exciton transfer is present between the chromophores of mb-OB3b.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

thesis

Discipline thesis:degree_discipline

Biochemistry

Department dc:contributor.department

Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology (LAS)

Year dc:date.issued

2016

Author dc:creator

• Turpin, Erick

Advisor dc:contributor.advisor

• Alan DiSpirito

Language dc:language.iso

en

DOI

https://doi.org/10.31274/etd-180810-5656

Identifier

archive/lib.dr.iastate.edu/etd/16029/

OAI identifier oai:identifier

oai:dr.lib.iastate.edu:20.500.12876/30212