Title

Mass Spectrometry and Computational Study of Ubiquitin Associated with Different Metal(Ii) Ions: Zinc, Copper, Nickel, Cobalt, Iron and Manganese

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

Fall 2012

Abstract

Mass spectrometry (MS) is an analytical technique that measures the mass-to-charge ratio of charged particles1. Mass spectrometry is an emerging tool used in the study of conformation, structure of protein and protein interactions with metal ions. Electrospray-Ionization (ESI) Mass Spectrometry is a 'soft' ionization technique which can be used in the analysis of large biomolecules like proteins because of its ability to form singly to multiply charged ions. ESI can also be used to study interactions of proteins with metal ions and non covalent interactions in the tertiary structure, because these interactions often change the shape or conformations of proteins. Mass spectrometry has wide spread use in biological analyses, particularly in the areas of proteins, and characterization of large macromolecules. Positive charged metallated-ubiquitin protein ions produced by electrospray ionization are mass selected by a quadrupole mass analyzer and then fragmented by collision-induced dissociation in the ion trap cell and m/z measurement of the fragments are done using a time of flight mass analyzer. The ion mobility allows the separation of ions based on cross sectional area and helps to study the conformation of ubiquitin and metallated-ubiquitin at various charge states from 6+ to 9+. Ubiquitin is a small 76 residue protein with a molecular weight of 8564.47 Da, which plays a key role in regulation of proteins by transferring the target proteins to proteosomes through the ubiquitin proteolysis cycle. The ubiquitin protein can interact with various metal ions. The interaction of ubiquitin with metal ions, the potential binding sites of metal ions, fragmentation of metallated-ubiquitin and conformational study of ubiquitin and metalated ubiquitin can be investigated by ESI-MS.

Advisor

Laurence Angel

Subject Categories

Chemistry | Physical Sciences and Mathematics

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