Protein structure and function, structural biology, magnetic resonance, metalloproteins.
More than 30% of all proteins in the cell exploit one or more metals to perform their specific functions, and over 40% of all enzymes contain metals. Metals are commonly found as natural constituents of proteins; however, many metal ions can be toxic when free in biological fluids. Hence, the human bodies as well as microorganisms have evolved considerable regulatory machinery to acquire, utilize, traffic, detoxify, and otherwise manage the intracellular and extracellular concentrations and types of metal ions. Despite the high regulation of metal ions in the human body, diseases such as Menkes, Wilson, Alzheimer’s, Parkinson’s and Prion’s have been linked with metal binding to proteins.
Dr. Ruthstein’s lab will look into some of the significant and least understood biological processes that are related to metal ion transportation and intracellular distribution, as well as unwanted processes due to high metal concentration or protein mutations. The aims are:
- To obtain structural information on intrinsically disordered N-terminal domain in metal transporters (such as Ctr1), in order to understand metal ion transportation to the cells.
- To understand the metal binding mechanism of metal sensors in bacterial cells, in order to shed light on the metal regulatory machinery of the bacteria (CueR, CsoR).
- To explore the copper transport and distribution mechanisms in human cells (from Ctr1 through Atox1 to Atp7b), in order to get to the core of the copper homeostasis mechanism.
- To characterize the role of copper and mutations on the aggregation,folding of proteins, and protein-protein interactions in bacteria and human cells.
To comprehend such processes it is necessary to be sensitive to the structural changes that occur in the protein upon metal binding. The main biophysical tool that is used in the lab of Dr. Ruthstein’s lab is pulsed EPR spectroscopy. The power of EPR lies in the sensitivity to both atomic level changes and nanoscale fluctuations. EPR can characterize properties such as redox state and ligand geometry for different functional states of the protein. In addition, EPR can measure distances between paramagnetic probes up to 80 Å
Part 1 I obtained my B.Sc in chemical engineering from the Technion, Haifa, Israel with summa cum laude honors. I then continued my graduate studies in the chemistry department at Weizmann Institute, Rehovot, Israel. I achieved my PhD with high honors under the supervision of Prof. Daniella Goldfarb. My research involved the use of Electron Paramagnetic Resonance (EPR) and cryo-TEM to resolve the formation mechanism of silica mesoporous materials. I published 9 papers and one review during my PhD. Two of my papers have been cited more than 100 times. After graduating from the Weizmann Institute in March 2008, I began my postdoctoral work, under the supervision of Prof. Sunil Saxena at the University of Pittsburgh, PA. Part 2 At this time, I noticed that many proteins contain metal ions natively, suggesting the use of paramagnetic metal ions as spin-labels to explore biological questions. One of my project was to resolve the coordination site of Cu(II) in the human Glycine receptor 240 kDa membrane protein. This was the first time that magnetic resonance experiments were carried out on such a large membrane protein. This work was published in the Biophysical journal. During my postdoctoral research, I also developed new methodologies to measure nanometre distances with high sensitivity between copper centres in proteins. One of the works was published in JPC B, and another in JMR. Part 3 I Joined the Department of Chemistry at BIU in October 2011. In my lab I aim to shed light on biological pathways that involve metal ion transportation. My main tool is EPR. With the aid of grants from the ISF, the Department of Chemistry has been able, in the last two years, to purchase two state-of-the-art EPR spectrometers, operating at two mw frequencies (X- and Q-bands). My main field is structural biology, in which I am exploring the traffic mechanism of copper ions in bacterial and human cells. This is an extremely novel and exciting field, since the molecular level pathways of copper ions in prokaryotic and eukaryotic cells is unknown. Copper ions are essential to the cells, however they can be toxic in elevated concentration. Part 4 Our vision is that by obtaining the full picture at the molecular level of the copper cycle, we will be able to control it according to specific needs, as well as to develop new therapeutic and diagnostic approaches.