Honors Program


Date of this Version

Spring 3-10-2022

Document Type



Jensen, Kailynn. Organic Synthesis of Tyrosine Derivatives for Analysis of Intracellular Phosphorylation. Honors Undergraduate Thesis. University of Nebraska-Lincoln. 2022.


Copyright Kailynn Jensen 2022.


Tyrosine phosphorylation is an important protein modification within cells, influencing processes ranging from homeostatic maintenance to the development of various diseases. However, it is often challenging to study, as the effects of a single phosphorylation event can mask or alter one another, making it highly desirable to phosphorylate and observe individual tyrosine residues. Furthermore, dynamic interconversion of phosphorylated and dephosphorylated isoforms can complicate biological investigations. Synthesis of non-canonical and non-hydrolyzable phosphorylated tyrosine derivatives, e.g., 4-(phosphonomethyl)-D,L-phenylalanine (PMP), followed by site-specific incorporation into proteins provides a path towards deciphering the roles of individual phosphorylation sites. For successful incorporation to occur, sufficient concentrations of PMP must be synthesized and taken into the cell. In this thesis, we report a successful synthetic procedure for PMP based on work by Baczko et al., which has previously been incorporated into bacterial proteins, and we propose a synthetic scheme to produce a PMP derivative with methyl pivalate groups that would allow more efficient passage into mammalian cells. We also illustrate successful synthesis of 4-(carboxymethyl)-D,L-phenylalanine (CMF) using procedures from Xie et al., which has already been incorporated into bacterial proteins. Significantly, we recently reported the incorporation of CMF as synthesized in this thesis into mammalian proteins.