Research Interests
My research interests are in the general area of iron-protein biochemistry and part of a major international effort to understand the role of iron in health and disease. The goal is to elucidate structure-function relationships of different iron-binding, iron-transport, and iron-storage proteins and better understand their roles in the regulation of cellular iron homeostasis. Our hope is to generate new knowledge that is essential for the rational development of new treatments for iron overload diseases and other defects in iron metabolism.
The importance of this research stems from the fact that iron is an element where you “Can’t live without it but you can’t live with too much of it”. Excess free iron has been implicated in neurodegenerative diseases, apoptosis (or cell death), and in the generation of harmful free radicals that cause damage to membranes, proteins and nucleic acids. The low solubility of iron at physiological conditions (~ 10-18 M) has compelled living organisms to adapt efficient iron transport and storage mechanisms. Of interest to our research program are two major iron-proteins including transferrin, a plasma iron transport protein, and ferritin, a ubiquitous and multi-subunit iron storage protein, both of which playing central roles in minimizing iron toxicity and controlling intracellular iron homeostasis. The two proteins have been used as nanotemplates in nanochemistry, nanobiology, and nanomedicine and have been the subject of intense investigation particularly because the uptake, storage, and release of iron are key cellular processes occurring during the normal course of iron metabolism. Current research efforts in our laboratory, supported by several grant agencies, including the National Institute of Health (NIH), the National Science Foundation (NSF), Research Corporation for the Advancement of Sciences, Dreyfus Foundation, and others (please see Grants and Awards), are aimed at understanding the effect of ferritin H and L subunit composition on iron core formation, morphology, iron mobilization and the physiological relevance of these processes. We believe that our research will provide fundamental insights into the role of the ferritin shell in controlling the morphology of the iron mineral and the biochemical processes responsible for iron-related disorders, such as Alzheimer, Parkinson, beta-thalassemia, hemochromatosis, and neuroferritinopathy. We collaborate with several national and international research groups including Profs, Paolo Arosio and Sonia Levi in Italy, Prof. Artem Melman at Clarkson University, NY, Prof. Georgia Papaefthymiou at Villanova University and Prof. Eric Stach at UPENN, among a few others.
Another important research project involves investigating the molecular basis of malaria and age-related macular degeneration. The World Health Organization estimated that malaria accounts for more than 200 million clinical cases worldwide and more than half-a-million deaths, mostly of children in sub-Saharan Africa. Although the disease is both preventable and curable, undesirable side effects from common drugs may lead to serious diseases. On the other hand, age related macular degeneration is the leading cause of blindness in individuals over 50 and is believed to be caused by a buildup of lipofuscin (yellow pigment granules formed as byproducts of lysosomal digestion), with A2E (a vitamin A-based bisretinoid) being a major component of that pigment. Our efforts in this area of research aim at investigating (A) the molecular mechanisms of two of the most prescribed anti-malaria drugs, Chloroquine and Atovaquone, and their interaction with a human lysosomal protein called saposin B (SapB), and (B) the role of SapB in binding A2E and in preventing age-related macular degeneration. To this end, we collaborate with Prof. Robert Doyle at Syracuse University, and Prof. Chloe Zubieta at the University of Grenoble, France.
Finally, we are working on a project aimed at developing a colorimetric sensor based on gold nanoparticles for the detection of toxic metals such as lead and hexavalent chromium in drinking water. Our goal is to achieve detection limits of 5-10 ppb for Pb2+ ions and 20-30 ppb for Cr6+, both of which are below the EPA recommendation of 15 ppb and 50 ppb, respectively. Additionally, we are trying to design a new method based on non-modified gold nanoparticles to detect and quantify proteins in aqueous solutions. Such method could complement or even outperform traditional protein detection and quantification assays such as Bradford or bicinchoninic acid assays, Lowry and Biuret protein assays which are prone to interference from metal ions that are typically associated with proteins, and thus lack accuracy and reproducibility, requiring multiple trials and tedious sample purification and preparations. Our goal is to design a new and more sensitive methodology to streamline this process and save time and resources.
Our research is supported by several federal agencies and private foundations resulting in over 3.0 million dollars in research funding (see Grants and Awards) and over 60 peer-reviewed publications (see Publications).
Interested students should contact Dr. Bou-Abdallah at bouabdf@potsdam.edu
Last Updated: 5/30/2024
Examples of Recently Completed Research Projects:
Iron Mobilization from Ferritin in Yeast Cell Lysate and Physiological Implications. We have conducted a series of iron release experiments from ferritin using fresh yeast cell lysates and compared the rates of iron mobilization to those in buffer. Our results indicate that in addition to ferritin proteolysis, there exist an auxiliary iron reductive mechanism that involves long-range electron transfer reactions. This paper has been published in the International Journal of Molecular Sciences, Int. J. Mol. Sci. 2022, 23, 6100. https://doi.org/10.3390/
Effect of Phosphate and Ferritin Subunit Composition on the Kinetics, Structure, and Reactivity of the Iron Core in Human Homo and Heteropolymer Ferritins. We have completed our investigation of the oxidative and reductive studies of iron deposition and iron mobilization in heteropolymer ferritins of different H to L subunit ratios, and the effect of phosphate and ferritin subunit composition on these processes. A paper on that topic has been published in Biochemistry. https://doi.org/10.1021/acs.biochem.2c00354
Micromagnetic and Morphological Characterization of Heteropolymer Human Ferritin Cores. We have completed performed Mossbauer and Scanning Transmission Electron Microscopy (sTEM) measurements on several isoferritin iron cores. The results of these studies have been accepted for publication in Nanoscale Advances (2022). https://doi.org/10.1002/pro.4543
Heteropolymer Hyperthermostable Recombinant Human Heteropolymer Ferritin Derived from a Novel Plasmid Design. This is the first report of recombinant human homo- and hetero-polymer ferritins that exhibit surprisingly high dissociation temperatures, the highest among all known ferritin species, including many known hyperthermophilic proteins and enzymes. This extreme thermostability of our L and L-rich ferritins may have great potential for biotechnological applications. A paper has just been accepted for publication in Protein Science (2022). https://doi.org/10.1002/pro.4543
Current Research Projects:
Investigation of the Roles of PCBP1 and NCOA4 in Determining the Fate of Intracellular Ferritin
Effect of ATP and NADH(P) on Iron Oxidation in Ferritin
CryoEM Structures of Human Heteropolymer Ferritins
Iron Core Structures and Morphologies in Human Recombinant Heteropolymer Ferritins
Detection of Lead in Drinking Water Using Gold Nanoparticles
Quantification of Proteins Interaction with Gold Nanoparticles
Ferritin Microheterogeneity: Subunit Composition, Function and Physiological Implications