Arianna Celis

Arianna Celis

Ph.D. candidate in Chemistry & Biochemistry

Arianna Celis studies heme, the complex of iron and the organic molecule protoporphyrin IX that is one of the most ancient and ubiquitous biological molecules. She is working on a recently discovered pathway for heme biosynthesis that is unique to several bacteria, including many important pathogens. This pathway ends in a step catalyzed by an unusual enzyme known as HemQ. Celis is studying the mechanism by which the HemQ in Staphylococcus aureus, a leading cause of bacterial infections of human skin and soft tissues, performs its function at the chemical and cellular levels. Researchers hope this work will result in a molecular-level understanding of HemQ’s role in Staphyloccocus aureus, which may be applicable to a full range of pathogens identified as emerging or relevant to biodefense such as Methicillin-resistant Staphylococcus aureus, Mycobacterium tuberculosis, Bacillus anthracis and others. Read more…

 

Amanda Fuchs

Amanda Fuchs

Ph.D. candidate in Chemistry & Biochemistry

Amanda Fuchs investigates the interactions between bacterial biofilms and human macrophages, a type of immune cell. Bacterial biofilms consist of densely packed communities of microbial cells that grow on living or inert surfaces. Biofilms are more resistant to antibiotic treatment and are known to evade the immune system. Bacteria residing within chronic wounds, such as diabetic foot ulcers, often form biofilms and have been shown to cause a significant delay in the healing time and closure of wounds due to excessive inflammation. A macrophage is a type of white blood cell found in most bodily tissues, where they survey the area for foreign substances, microbes and cellular debris. It is speculated that macrophages are primarily responsible for the resolution of inflammation in wounds. Fuchs is studying the metabolites and metabolic pathways involved in the interactions between Pseudomonas aeruginosa biofilms and human macrophages to gain insights into the cellular mechanisms contributing to persistent inflammation in chronic wounds. Read more…

 

Amanda Byer

Amanda Byer

Ph.D. candidate in Chemistry & Biochemistry

Amanda Byer investigates one of the largest enzyme super families that exists in all domains of life: the radical S-adenosyl-L-methionine (SAM) enzyme superfamily. When human radical SAM enzymes fail, it can lead to diseases such as viral infection, diabetes mellitus, impaired cardiac and respiratory function, congenital heart disease and cofactor deficiency. Through a SAM and iron-sulfur cluster moiety, radical SAM enzymes generate a radical, or unpaired electrons, which can be destructive in biological systems if uncontrolled. Byer's research uses various spectroscopic techniques to examine radical SAM enzyme active-sites and identify how radical chemistry is constrained by the protein environment in these organometallic biochemical systems. Read more…