Protein-Based Molecular Sensors for Hyperpolarized Xenon NMR / Zhuangyu Zhao.

Format:

Book

Thesis/Dissertation

Author/Creator:

Zhao, Zhuangyu, author.

Contributor:

University of Pennsylvania. Chemistry, degree granting institution.

Language:

English

Subjects (All):

Chemistry.

Biochemistry.

Medical imaging.

Chemistry--Penn dissertations.

Penn dissertations--Chemistry.

Local Subjects:

Chemistry.

Biochemistry.

Medical imaging.

Chemistry--Penn dissertations.

Penn dissertations--Chemistry.

Physical Description:

1 online resource (164 pages)

Distribution:

Ann Arbor : ProQuest Dissertations & Theses, 2023

Contained In:

Dissertations Abstracts International 85-08B.

Place of Publication:

[Philadelphia, Pennsylvania] : University of Pennsylvania, 2022.

Language Note:

English

Summary:

To elucidate important biological processes, it is essential to employ molecular imaging techniques that provide excellent sensitivity, selectivity, and spatiotemporal resolution. Magnetic resonance imaging (MRI) is a non-invasive imaging technique with virtually unlimited penetration depth due to the radiofrequencies employed. However, conventional 1H MRI techniques have intrinsic limitations, such as low sensitivity and lack of molecular details. To address these limitations, hyperpolarized (HP) 129Xe NMR and MRI have been developed as complementary methods owing to the significant signal enhancement afforded by hyperpolarization and also xenon's biocompatibility. HP 129Xe in combination with chemical exchange saturation transfer (hyper-CEST) NMR improves the limit of detection to sub-picomolar range, in comparison to the hundreds of micromolar contrast agents typically required for 1H-based NMR detection. Furthermore, protein-based contrast agents offer many advantages over synthetic contrast agents, including molecular targeting specificity, genetic programmability, and low toxicity. Previously, our laboratory developed genetically encoded 129Xe NMR contrast agents based on TEM-1 β-lactamase, maltose binding protein (MBP), and ribose binding protein (RBP).First, we employed molecular dynamics (MD) simulations and hyper-CEST NMR technique to elucidate the interaction of Xe with MBP. The 129Xe hyper-CEST signal is highly programmable using an interdomain salt bridge K15-E111 in MBP. Next, we converted this salt bridge into a zinc binding site via rational design, which enabled sensitive and selective detection of cellular Zn2+ by 129Xe hyper-CEST. The same site can also be reconstructed using a s-tetrazine-based photocleavable linker, thus enabling optical control of magnetic resonancecontrast. Finally, the split TEM-1 β-lactamasecan be used to monitor proteinprotein interactions in bacterial cells with NMR signal readouts. In conclusion, these results highlight the potential to develop proteins, especially the family of periplasmic binding proteins, as molecular sensors for NMR spectroscopy and MRI.

Notes:

Source: Dissertations Abstracts International, Volume: 85-08, Section: B.

Advisors: Dmochowski, Ivan J.; Rhoades, Elizabeth; Committee members: Berry, Donald H.; Matthews, Megan L.

Department: Chemistry.

Ph.D. University of Pennsylvania 2023.

Local Notes:

School code: 0175

ISBN:

9798381509960

Access Restriction:

Restricted for use by site license.