Investigation of the Interaction Between Cytochrome b(H) and the Q(i)-Site in Rhodobacter Sphaeroides

In characterization of strains generated with mutations at the Q i-site, it was noticed that several paradoxical properties could not be readily explained under current paradigms of mechanism, leading to a reinvestigation of the thermodynamic properties of the main redox partners involved---heme bH and the SQ---and the mechanistic consequences of mutation in key residues. Notable findings of this work are that the pH dependence of the midpoint potential of cytochrome bH differs substantially from what was published previously; a high potential component of bH remains even in the presence of Antimycin, and the thermodynamic properties of bH are substantially modified in strains with mutations at Asparagine 221. There also appears to be substantial redox cooperatively between the hemes of the complex, which is more pronounced in some of the mutants studied. The relationship between b150 and the Qi site SQ was also investigated.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biophysics and Computational Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Holland, J. Todd

Contributors dc:contributor

• Anthony R. Crofts

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI3290248

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85460