Speakers

Student presenting at Senior Symposium, text reads: Sciences

Student Abstracts: Cleveland L2 - Panel D

Sciences

Elizabeth Kuehne, Chemistry
Paper to Plastics: Developing Novel Cellulose-Based Material
Project Advisor: Kyle Broaders

Cellulose is the most abundant renewable organic polymer. Moreover, it possesses qualities which make it ideal for modifications into a variety of materials, many of which are currently commercially available as alternatives for petroleum-based plastics. Global demand is increasing for renewable and biodegradable alternatives to petroleum-based plastics, and new cellulose-based materials have potential to meet these needs. The Broaders Lab has used acetalation as a means of modifying cellulose to alter its hydrophilicity and increase solution processability. Acetalated cellulose (AcCell), is soluble in polar organic solvents like THF, dioxane, and DMSO, allowing it to be solution-processed and molded into films. The acid-sensitivity of the acetal-modified groups also allow for cellulose to be readily regenerated from AcCell. This feature of the material has been explored in the contexts of templatable materials and fiber-making. Furthermore, the extrusion of AcCell dissolved in DMSO into acidic water has demonstrated that AcCell can produce regenerated cellulose fibers. Films of AcCell have been etched by acid to create hydrophilic channels. Hydrolysis of AcCell produces only acetone and methanol as byproducts, showing promise as a more environmentally friendly regeneration technique. This material proves promising as a plastics alternative in an array of applications.
 

Maria Monterroso, Chemistry
Screening for Protein-Macromolecule Interactions using Fluorogenic Dyes
Project advisor: Jonathan Ashby

Biological interactions in the human body are essential for biological processes; however, some biological processes lead to the aggregation and/or misfolding of proteins that may cause the development of neurobiological diseases.1 It’s important to understand protein-macromolecule interactions in order to develop complementary methods that help determine how these interactions develop, as well as a way to inhibit them.

In this project, fluorescamine-based tagging of protein surfaces was used to identify protein-macromolecule interactions. Fluorescamine is a chemical dye that is non-fluorescent on its own but becomes fluorescent when it reacts with primary amines.2 Of the natural amino acids, fluorescamine will selectively react with lysine. However, if two proteins interact, fluorescamine can no longer react at the interface where the interaction is occurring. This will lead to a decrease in fluorescence signal which can be used to determine whether a protein-macromolecule interaction has occurred. In order to enhance the sensitivity of the assay, incubation parameters were tested such as the pH of the solution. To test the hypothesis, two well-characterized biomolecular complexes were evaluated. The first complex was between immunoglobulin G and immunoglobulin-binding protein A. The second complex tested was between thrombin and two nucleic acid aptamers that bind to different sites on the protein. In both of these cases, the expected reduction in fluorescence was observed. Findings suggest that fluorescamine can be used to identify protein-macromolecule interactions. Further research can be done to determine whether other fluorogenic dyes with higher sensitivities and selectivity to proteins can be used to identify protein-macromolecule interactions, as well as whether the binding of fluorescamine can be used to determine the location of the protein-macromolecule interaction.
1 Jokar, S., Khazaei, S., Gameshgoli, X. E., Khafaji, M., Yarani, B., Sharifzadeh, M., Beiki, D., & Bavi,
O. (2020). Amyloid β-Targeted Inhibitory Peptides for Alzheimer’s Disease: Current State and Future
Perspectives. In X. Huang (Ed.), Alzheimer’s Disease: Drug Discovery. Exon Publications.
2 Signa Aldrich. Fluorescamine (2022). https://www.sigmaaldrich.com/US/en/product/sigma (Accessed
March 23, 2022)
 

Katie Benway, Biochemistry
A Novel Immunoassay for Multiplex Detection of Heat Shock Proteins using XMap Technology
Project Advisor: Kathryn McMenimen

Protein chaperones are key molecules that maintain proteostasis in the body. Heat shock proteins (HSP) specifically are a class of stress-response chaperone proteins which prevent misfolding, aggregation, and degradation of proteins. Detecting the presence and quantity of these proteins in organisms under stress can tell us about the effect of stress conditions on proteostasis and the organism overall.

To study the implications of various stress responses on HSP response, we are developing a method for constructing heat shock-protein-specific fluorescent microbeads (with xMAP microbead technology) for use in robust multiplex immunoassays, which can be used to identify multiple HSPs in brain tissue samples from mice. The immunoassays are developed via antibody conjugation to fluorescent and magnetic microbeads, which are used to quantify Hsps in multiplexed conditions.

Currently, we have constructed several different Hsp-labeled microbeads and successfully run several antibody-microbead confirmation protocols on a Luminex MagPix. Method development will ensure specific coupling of antibodies (HSP27 and HSP70) to the microbeads via a fluorescent-marked dilution series of secondary antibodies and titration assays. Project aims are to optimize the coupling and confirmation techniques and run protein-spiked assays to confirm successful conjugation including: cross-reactivity assays to evaluate the coupled beads, and the evaluation of targeted capture of heat shock proteins in mice brain tissue. These methods will enable both high-throughput screening of tissue samples and contribute to the understanding of the complex proteostasis network that responds to stress and prevents protein aggregation disease.