Graduate Program
Chemistry
Degree Name
Master of Science (MS)
Semester of Degree Completion
2007
Thesis Director
Doug Klarup
Thesis Committee Member
Mark McGuire
Thesis Committee Member
Gopal Periyannan
Thesis Committee Member
Scott Tremain
Abstract
Metalloproteins have the capacity to bind various metal ions. In spite of this seemingly diverse choice of cofactors, metalloproteins generally bind only their cognate metal in vivo. Cytochrome c (cyt c) binds Fe porphyrin in vivo. The main objective of this thesis is to investigate why nature selects Fe porphyrin as the prosthetic group in heme proteins and how removal of the native Fe in cyt c and substitution by different metal ions affects the local coordination environment, overall structural stability, and biological function. Our goal is to prepare and characterize metal-free cytochrome c, socalled porphyrin cytochrome c (H2cyt), and its various metal-substituted derivatives, specifically Mn-substituted cytochrome c (Mncyt). We have studied the rates of incorporation of Mn(II) into H2cyt to better understand metal ion's optimal incorporation conditions and its mechanism, under different denaturating conditions like urea and temperature. Compared to H2cyt, metal-substituted cytochromes have significantly different absorbance spectra, so we monitor over time the change in absorbance upon addition of Mn(II) chloride. Moreover, in order to compare the structural stability of native Fe cytochrome c (Fecyt) with H2cyt, zinc cytochrome c (Zncyt) and Mncyt, guanidine hydrochloride(GdnHCI) denaturation curves are obtained using absorbance and fluorescence spectroscopy. The relative structural stabilities of H₂cyt, Fecyt, Zncyt and Mncyt will be presented.
Recommended Citation
Gundala, Vineela, "Metal-substituted cytochrome c: Manganese (II) incorporation kinetics and structural stability studies of native iron cytochrome c, porphyrin cytochrome c, zinc cytochrome c and manganese cytochrome c" (2007). Masters Theses. 74.
https://thekeep.eiu.edu/theses/74
