Fluorescence and computational studies of thymidine phosphorylase affinity toward lipidated 5-FU derivatives

Area of Science:

• Biochemistry and Molecular Biology
• Enzyme Kinetics and Inhibition
• Drug Delivery Systems

Background:

• Thymidine phosphorylase (TP) is upregulated in various solid tumors, contributing to cancer growth and metastasis.
• TP plays a dual role in cancer: a target for inhibition and a facilitator for activating the chemotherapy drug 5-fluorouracil (5-FU).

Purpose of the Study:

• To investigate the intrinsic fluorescence of thymidine phosphorylase (TP) for the first time.
• To evaluate the binding affinity of 5-FU and its liposomal derivatives to TP.
• To explore the potential of designed supramolecular lipid structures for TP targeting.

Main Methods:

• Utilized intrinsic TP fluorescence to study binding interactions.
• Synthesized and tested two 5-FU derivatives functionalized with glycol chains and an alkyl moiety.
• Employed molecular dynamics simulations and docking calculations to support experimental findings.

Main Results:

• 5-FU derivatives (1 and 2) demonstrated a micromolar binding affinity for TP, approximately 10 times higher than unsubstituted 5-FU.
• High affinity was retained when derivatives were incorporated into liposomal membranes.
• Computational methods corroborated the experimental observations.

Conclusions:

• Designed liposomal 5-FU derivatives exhibit significantly enhanced binding affinity for TP.
• These findings support the potential application of these supramolecular lipid structures as selective TP-targeting agents.
• The developed system could be utilized as a drug delivery system or a sensor device for cancer therapy.