Investigation of the Selected Transition Metal Binding Characteristics of Methanobactin from methylosinus Trichosporium Ob3b
Master of Science (MS)
Date of Award
The methanobactin (Mb) from Methylosinus trichosporium OB3b (1154.26 Da) is a member of a class of metal binding peptides identified in methanotrophic bacteria. Mb will selectively bind and reduce Cu(II) to Cu(I), and they are thought to mediate the acquisition of the copper cofactor for the enzyme methane monooxygenase. Mb will also bind other metal ions and mediate their solubilization and transportation in situ. The structure of Mb consists of nine amino acids and two modified regions containing enethiol-oxazolone rings which are the bidentate binding sites for Cu(I). However, the binding characteristics for Ag(I), Pb(II), Co(II), Fe(III), Mn(II), Ni(II), and Zn(II) have not been determined and the goal of this study is to compare the binding of these metals to the [Mb+Cu(I)- nH](n-1)− complex using traveling wave ion mobility mass spectrometry (TWIMS). The arrival time distribution (ATD) for each metal complex and free Mb was used to quantify the apparent binding affinity and measure their collision cross section at various pH points. In addition, collision-induced dissociation of the disulfide reduced [Mb+M], was used to locate the binding sites of the individual metal(I or II) ions (M), and the normalized collision energy, breakdown curve was measured to determine the relative stability of the [red-Mb+M] complexes. Selected mass spectrometry titration studies were repeated using fluorescence spectroscopy to compare gas-phase and solution-phase techniques.
Laurence A Angel
Chemistry | Physical Sciences and Mathematics
McCabe, Jacob Watson, "Investigation of the Selected Transition Metal Binding Characteristics of Methanobactin from methylosinus Trichosporium Ob3b" (2017). Electronic Theses & Dissertations. 811.