“Synthetic and genetically encoded biosensors and contrast agents for ultrasensitive 129Xe NMR” *
Serge Zemerov
Ph.D. Student and TCNJ Alumni
Department of Chemistry
University of Pennsylvania
Date: Wednesday, March 28th
Time: 11:00 AM
Room: Chemistry C121
ABSTRACT
Proton-based magnetic resonance imaging (1H MRI) is a widely used technique for the detection and diagnosis of human disease states. However, it is poorly suited for imaging void spaces, due to its reliance on the proton signal from endogenous water and fat. Additionally, 1H MRI experiments require high sample concentrations and/or long acquisition times due to the low sensitivity inherent in the technique, limiting its use in imaging low-abundance biomarkers. To overcome these issues, hyperpolarized 129Xe NMR and MRI have been investigated as complements to 1H-based techniques. In this talk, I will summarize our laboratory’s efforts to develop 129Xe-based imaging as a complement to traditional 1H MRI. Specifically, I will focus on the synthesis and characterization of the small organic Xe host molecules known as cryptophanes, as well as on our studies of genetically encoded (GE) 129Xe NMR contrast agents. The chemical shift of 129Xe is highly sensitive to its chemical environment due to its large and polarizable electron cloud, which allows for the use of 129Xe NMR to detect the binding of a functionalized cryptophane cage to various biomedically relevant proteins. Additionally, we have recently identified two proteins, TEM-1 β-lactamase and maltose binding protein, as potential GE xenon biosensors, which have the advantages of being expressed directly in the tissue of interest and tailored to bind specific analytes. These synthetic and GE biosensors offer exciting possibilities for advancing ultrasensitive detection of ions, small molecules, and proteins via 129Xe NMR/MRI.
*PI: Dr. Ivan J. Dmochowski