Title

Study of Methanobactin and Methanobactin Analog Peptides for Selective Binding of Cu(Ii) and Zn(Ii) Ions

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

Summer 2013

Abstract

Methanobactins are low molecular mass chromopeptides that play an important role in metabolism of methanotrophic bacteria by acting as an extracellular copper acquisition system. The methanobactin obtained from Methylosinus trichosporium OB3b (mb-OB3b) has a molecular mass of 1154 Da and is composed of 7 amino acid residues with two oxazolone rings placed in vicinity of enethiols, which take part in binding to copper ions. Methanobactin analog peptides are synthetic, simplified structural forms of mb-OB3b designed to discover which features of mb-OB3b are important for its copper ion selectivity. The mb-OB3b analog peptides which will be studied, replace the oxazolone and enethiol groups with histidine and cysteine groups, respectively, which are the binding groups of a class of peptides called zinc fingers. The study will determine whether the mb-OB3b analog peptides exhibit methanobactin or zinc finger like behavior. In this study, we will use the method of continuous variation to determine the binding stoichiometry and affinity constants of mb-OB3b and mb-OB3b analog peptides for Cu(II) or Zn(II) ions.

Advisor

Laurence Angel

Subject Categories

Chemistry | Physical Sciences and Mathematics

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