Degree Type

Thesis

Date of Award

2007

Degree Name

Master of Science

Department

Biochemistry, Biophysics and Molecular Biology

First Advisor

Mark Hargrove

Abstract

Hexacoordinate hemoglobins (HxHbs) have recently been discovered and have been found in nearly all living organisms. In humans, hxHbs are represented by neuroglobin (Ngb) and cytoglobin (Cgb). While Ngb is principally found in the brain, Cgb is ubiquitously expressed in all tissues. Ligand binding in hexacoordinate hemoglobins is complex due to the reversible coordination of the heme iron by the distal histidine. Hexacoordination regulates ligand binding and is regulated by specific residues in the heme pocket including the B10 position. Therefore, we investigated the influence of LeuB10 on hexacoordination and ligand binding in Cgb. Ligand binding was analyzed for recombinant proteins, Cgb B10A Cgb B10F. The results obtained showed that LeuB10 plays a crucial in hexacoordination. Interestingly, due to the mutants' low CO affinity it was possible to measure the CO affinity equilibrium constant (Ka) by equilibrium titration similar to the Ka calculated from individual rate constants extracted from kinetics.

DOI

https://doi.org/10.31274/rtd-180813-15739

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Jordan Richard Witmer

Language

en

Proquest ID

AAI1443087

OCLC Number

163570997

ISBN

9781109818048

File Format

application/pdf

File Size

41 pages

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