Polyethylene glycol (PEG) is a flexible, non-toxic polymer. It is considered biologically inert and has numerous applications in medicine and industry. PEG is often attached to drug molecules in a process called PEGylation to enhance their stability and solubility, decrease the immune response, and increase circulation time throughout the body. Recently, PEGylated lipids have been included as an ingredient in COVID-19 vaccines. Additionally, PEG molecules of variable sizes are commonly used for studying the effects of molecular crowding and confinement on the conformation and function of proteins and nucleic acids. Despite being considered biologically inert, recent studies have shown that PEG interacts with biomolecules such as proteins. To gain a deeper understanding of PEG-protein interactions, we are using Raman Spectroscopy to investigate the effect of PEG of variable sizes on the vibrational modes of amino acids and proteins. This vibrational spectroscopic technique identifies unique fingerprints of molecules based on the inelastic scattering of monochromatic light. We will present the preliminary results of our study.
