Investigation of Protein Conformation With Novel Labeling Techniques Using Electron Paramagnetic Resonance Spectroscopy

Access Restricted

Access to this document is restricted. Some items have been embargoed at the request of the author, but will be made publicly available after the "No Access Until" date.

During the embargo period, you may request access to the item by clicking the link to the restricted file(s) and completing the request form. If we have contact information for a Cornell author, we will contact the author and request permission to provide access. If we do not have contact information for a Cornell author, or the author denies or does not respond to our inquiry, we will not be able to provide access. For more information, review our policies for restricted content.

No Access Until

Permanent Link(s)

Other Titles


At the molecular level, proteins form the basis for numerous functions across biology, ranging from immune responses to metabolism. A detailed knowledge of protein structure and conformational dynamics is crucial for understanding function and mechanism. As such, numerous biophysical techniques have been used to investigate protein structure and dynamics. One such technique, Electron Paramagnetic Resonance (EPR) spectroscopy, is particularly valuable for investigating protein conformational changes across a diverse range of proteins, including intrinsically disordered proteins and large macromolecular complexes. In this thesis, EPR spectroscopy is used to investigate a range of biological systems, including the Drosophila circadian clock and the E. coli aerotaxis response. In order to enable a greater range of proteins to be studied using EPR, enzymatic spin labeling strategies are developed to overcome the disadvantages associated with traditional labeling methods. Enzymatic labeling techniques using various peptide ligating enzymes allows specific attachment of EPR active probes to the N and C-termini of various proteins, enabling a general method for study of proteins using EPR. Furthermore, enzymatic labeling is used to investigate the conformational dynamics of the protein Period, a key component of the Drosophila circadian clock. Phosphorylation of Period has been previously shown to be a key regulator of Period stability and function. Using various EPR techniques, phosphorylation of Period is shown to heavily influence the local dynamics of Period, which likely affects the interaction of Period with other binding partners in vivo. Additionally, other complexes in the Drosophila circadian clock are investigated. Lastly, EPR is used to investigate the conformations of Aer, a transmembrane receptor responsible for the movement towards oxygen in E. coli. A combination of isotope labeling and co-expression with binding partners enables the in vivo study of Aer in its native signaling environment, revealing formation of cooperative signaling arrays. Overall, these labeling strategies along with complimentary biophysical methods provide avenues for investigation of various biological systems that are difficult to study with traditional methods.

Journal / Series

Volume & Issue


169 pages


Date Issued




Circadian Clock; DEER; EPR; Spin-Labeling


Effective Date

Expiration Date




Union Local


Number of Workers

Committee Chair

DeLisa, Matthew

Committee Co-Chair

Committee Member

Crane, Brian
Lin, Hening

Degree Discipline

Chemical Engineering

Degree Name

Ph. D., Chemical Engineering

Degree Level

Doctor of Philosophy

Related Version

Related DOI

Related To

Related Part

Based on Related Item

Has Other Format(s)

Part of Related Item

Related To

Related Publication(s)

Link(s) to Related Publication(s)


Link(s) to Reference(s)

Previously Published As

Government Document




Other Identifiers


Rights URI


dissertation or thesis

Accessibility Feature

Accessibility Hazard

Accessibility Summary

Link(s) to Catalog Record