Chemistry Commons^™

Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman

Honors Theses

The continued burning of fossil fuels is not only a cause of increasing deterioration of the environment but also a financially unsustainable source of energy. Advances in energy production must be investigated to avoid the long-term effects of this current main source of energy. One of the avenues being explored is the use of metalloenzymes to catalyze hydrogen evolution via water splitting that occurs during the reductive half of artificial photosynthesis. Metalloenzyme catalysts with a single Ni(Cys)₄ active site have been previously studied, and this study explores the possibility of increasing hydrogen production by using metalloenzyme catalysts with multiple …

Bismuth Binding In Human Metallothionein, Emily M. Toswell

Undergraduate Student Research Internships Conference

Bismuth metal is one of the least toxic heavy metals for humans. It is used in a wide variety of applications including organic synthesis, cosmetics and pharmaceutical applications. In biomedicine, bismuth is a therapeutic metal used in metallodrugs such as Pepto Bismol for its antimicrobial and antibacterial properties. Metallothionein (MT) is a cysteine rich protein found in the liver, kidneys, brain and central nervous system. MT can bind a variety of metals including essential metals such as zinc and copper. This research investigates the binding pathway of Bi[EDTA]- with fully metallated Zn₇MT by using mass-spectrometry and UV-vis absorption.

Cysteine Metallochemistry And Metal Binding: Quantification Of The Thermodynamic Foundations Of Cellular Homeostasis, Matthew R. Mehlenbacher

Dartmouth College Ph.D Dissertations

Metals are required for life. Many metalloproteins contain cysteine in their metal-binding site (MBS) and cysteines are unique in that they are reactive, and strongly bind certain metals, which aid in metal selectivity and specificity. Using isothermal titration calorimetry (ITC), the thermodynamic foundation for metal binding, cellular protection, and transcriptional regulation, which all utilize cysteines in their MBS, are quantified.

In bacteria there are metalloprotein pathways that actively uptake mercury, which are regulated by the metalloregulatory protein MerR. MerR de-represses the transcription of these mer proteins in a metal-dependent manner. Using ITC, the thermodynamic foundation of the negative allosteric coupling …

Non-Traditional Metallation Of Metallothioneins With Xenobiotic Therapeutic Metals, Daisy L. Wong

Electronic Thesis and Dissertation Repository

The rise of the Anthropocene has seen more global pollution than before in history. With the explosion of consumer electronics in the last half century, the rise of metal pollution from their extraction and disposal results in the unnatural introduction of heavy and rare metals into the ecosystem. Organisms have a metal defense protein, metallothionein, which has multiple roles in essential metal regulation and protection against minimal toxic metal exposure. However, these modern heavy metals prominent in electronics are not found biologically and their interactions in the body are generally unknown. Some of these metals are employed as therapeutic agents …

Metalation And Structural Properties Of Apo-Metallothioneins, Gordon W. Irvine

Electronic Thesis and Dissertation Repository

Metals are required by a quarter of all proteins to achieve their biological function, whether in an active site involved in catalytic chemistry or in a structural capacity. Metals are tightly regulated at the cellular level due to their propensity to cause unwanted side reactions and to be scavenged for use by pathogens. One of the proteins involved in this regulation of metal homeostasis is metallothionein (MT) which is a small, cysteine rich protein primarily involved in the regulation of zinc and copper homeostasis and heavy metal detoxification. MT is unique in its high cysteine content (~30% of the residues), …

Reactions Between Zinc Metallothionein And Carbonic Anhydrase, Tyler B. J. Pinter

Electronic Thesis and Dissertation Repository

More than 25% of proteins require metal ion cofactors for structure or function. The interactions between metalloproteins have largely been overlooked, though these interactions ultimately govern metal localization and control metal ion homeostasis. Mammalian metallothionein (MT) is a small, cysteine-rich metalloprotein that binds numerous metal ions per protein strand. Up to seven divalent metals, such as zinc or cadmium, are wrapped into a clustered two-domain structure. This unusually high metal content places MT as an attractive candidate for studying interactions with other metal-binding proteins. This present study investigates the metal transfer reactions between MTs and other metalloproteins, using carbonic anhydrase …

Structural Motifs Of Novel Metallothionein Proteins, Duncan E K Sutherland

Electronic Thesis and Dissertation Repository

Metallothioneins (MT) are a family of small cysteine rich proteins, which have been implicated in toxic metal detoxification, protection against oxidative stress, and as a metallochaperone. The most well studied member of the family is the mammalian MT, which consists of two domains: a β-domain with 9 cysteine residues, which sequesters 3 Cd²⁺/Zn²⁺, and an α-domain with 11 cysteine residues, which sequesters 4 Cd²⁺/Zn²⁺. The exact functions of MT are unknown but must relate to its metalation status. Several areas that could lead to the assignment of function include 1) the determination …