Title

Investigation of Metal Binding Properties of Methanobactin and Alternative Methanobactin (amb7) Peptides by Fluorescence Spectroscopy and Ion-mobility Mass Spectrometry

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

Spring 2017

Abstract

Methanobactin (mb-OB3b) is a copper-binding oligopeptide produced by Methylosinus trichosporium OB3b, a class of low molecular weight chalkophore, similar to iron-binding siderophores, and are believed to mediate copper acquisition from the external environment of the methanotrophs. The redox activity and metal binding of methanobactin and three alternative metal binding peptides (amb7-0, amb7-1 and amb7-2), all the three with the same amino acid sequence CH3CO-Leu1-His2-Cys3-Gly4-Ser5-Cys6-Tyr7-Pro8-His9-Cys10-Ser11-Cys12-Met13 but differing by having either zero, one or two disulfide bridges between Cys3 and Cys10, and Cys6 and Cys12 are studied as a function of their metal binding ability. The metal ions investigated include Cu(II), Zn(II), Mn(II), Ni(II), Pb(II), Co(II), Ag(I), and Fe(III). By preparing solutions of 1:1.5 molar equivalents of the amb7: metal ion at pH 5, 7, 9 and 11, metal binding studies will be investigated using ion mobility - mass spectrometry (IM-MS). Similarly, the metal ions are also studied with the same 1:1.5 molar equivalents of the Mb: metal ion using fluorescence spectroscopy. The research is focused on comparing metal binding properties of methanobactin from Methylosinus trichosporium OB3b with alternative methanobactin (amb7) peptide.

Advisor

Laurence Ambrose Angel

Subject Categories

Chemistry | Physical Sciences and Mathematics

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