Advisor(s)

Zhaohui S. Zhou

Contributor(s)

Michael P. Pollastri, George A. O'Doherty

Date of Award

2012

Date Accepted

4-2012

Degree Grantor

Northeastern University

Degree Level

M.S.

Degree Name

Master of Science

Department or Academic Unit

College of Science. Department of Chemistry and Chemical Biology.

Keywords

chemistry, adomet, analogue, methyltransferase, specificity, substrate

Subject Categories

Methionine, Enzymes - Synthesis

Disciplines

Analytical Chemistry

Abstract

Determining enzyme-substrate specificity is tantamount to understanding biology on a molecular level. In medicinal chemistry, for example, this is often the crucial starting point from which a drug discovery project emanates. Understanding specificity can be a markedly difficult task, however, especially in the case of S-adenosyl-methionine (AdoMet or SAM)-dependent methyltransferases. Functional analysis of these enzymes is complicated by the fact that the methyl group is only 15 Daltons and unreactive, which, especially in the case of more complex systems, necessitates the use of creative solutions.

The development of AdoMet analogues is one such solution, allowing for substrate labeling with larger and more reactive groups or enzyme-mediated adduct formation. As presented herein, an AdoMet analog that contains an electrophilic "hook" forms a covalent adduct with the nucleophilic methyltransferase substrate. In the case of S-adenosyl-vinthionine (AdoVin), the electrophilic group is a vinyl sulfonium, which forms a bi-substrate adduct with its substrate, making detection of substrates facile. I describe herein the enzymatic synthesis of S-adenosyl-vinthionine and the chemical synthesis of vinthionine, its corresponding methionine analogue. Furthermore, the method is validated with thiopurine methyltransferase (TPMT).

Document Type

Master's Thesis

Rights Holder

Nathaniel Thomas Kenton


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