Publication Date

Spring 2023

Degree Type


Degree Name

Master of Science (MS)




Ningkun Wang

Subject Areas



The N-terminal of protein SIRT1 contains an intrinsically disordered region named motif A. Motif A’s lack of structure does not equate to a lack of function, the region can still participate in binding to and regulating the activity of SIRT1. This research aims to elucidate the mechanisms behind motif A’s ability to regulate SIRT1 activity, likely through a binding interaction. Motif A may potentially contain a molecular recognition feature (MoRF) which is natively unstructured but becomes structured after interaction with a binding partner. In regards to the goals of the research, the hypothesis of the project is: when certain amino acids within motif A become phosphorylated, its binding affinity to SIRT1 becomes stronger, and the activity of the protein increases. Qualitative information on binding activity of motif A on SIRT1 is available, but quantitative values have not been determined, thus hampering the ability to compare binding properties of wild-type and phosphorylated motif A. This project uses mutated serine amino acids S27 and S47 into aspartate to mimic phosphorylated serine properties such as electrostatics and sterics. The project utilized fluorescence polarization to observe binding interactions of different motif A constructs with the rest of SIRT1, and comparing the binding interactions under different scenarios, such as the addition of substrates or using different lengths of SIRT1.

Available for download on Wednesday, August 30, 2028