Spectroscopic Investigation of Helicobacter pylori Catalase Compound Ii
Open Access
Author:
Langston, Matthew Carroll
Graduate Program:
Chemistry
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
May 04, 2012
Committee Members:
Michael Thomas Green, Thesis Advisor/Co-Advisor
Keywords:
catalase compound II Mossbauer EXAFS
Abstract:
Cytochome P450 plays an active role in many essential physiological oxygen activation processes such as xenobiotic metabolism and steroid hormone synthesis. These thiolate-ligated heme proteins function in two-electron oxidations by proceeding through an iron(IV) intermediate. This transitional species is similar to those of histidine- and tyrosine-ligated heme proteins. Thiolate-ligated proteins, however, are believed to possess a unique ferryl-hydroxo intermediate that facilitates their reactivity through a strong distal ‘push’. In an effort to understand what role this thiolate ligation plays in C-H bond activation, we have undertaken an investigation of catalase, a tyrosine-bound heme peroxidase, to determine the existence of other ferryl hydroxides in heme proteins. Spectroscopic studies have reported unexpected bond lengths for catalase compound II, indicating protonation. In this study, UV/Vis, Mössbauer, and x-ray absorption spectroscopies (XAS) will be used to clarify the protonation status of Helicobacter pylori catalase.
