An Oxyprenylated Phenylpropanoid Pharmacologic Scaffold for SelU Inhibition

Area of Science:

• Biochemistry
• Enzymology
• Drug Discovery

Background:

• TRNA 2-selenouridine synthase (SelU) is a bacterial enzyme essential for modifying uridine at the wobble position, maintaining base pair fidelity.
• SelU is a promising drug target due to its essential role and bacterial exclusivity.
• Existing knowledge of SelU's catalytic mechanism aids in rational drug design, despite the lack of a determined molecular structure.

Purpose of the Study:

• To screen oxyprenylated phenylpropanoids for their potential as SelU ligands.
• To investigate the binding mode and interactions of these compounds with SelU.
• To establish a pharmacologic scaffold for developing novel antibiotics targeting SelU.

Main Methods:

• Selection of natural and semisynthetic oxyprenylated phenylpropanoids based on structural similarity to known SelU ligands.
• Fluorescence quenching assays using an N-terminal SelU construct and tryptophan W83.
• Calculation of bimolecular quenching constants to infer enzyme-substrate binding dynamics.

Main Results:

• Screening identified specific oxyprenylated phenylpropanoids with affinity for SelU.
• Analysis of quenching constants suggests conformational flexibility around W83 and a single binding site.
• The study reveals a blend of interaction types at the SelU active site.

Conclusions:

• Oxyprenylated phenylpropanoids, particularly those with geranyl groups and a cinnamic acid moiety, represent a viable pharmacologic scaffold.
• This scaffold can be optimized for the development of novel antibiotics targeting SelU.
• The findings provide insights into SelU-ligand interactions, guiding future drug development efforts.