Elucidating the structure-function attributes of a trypanosomal arginyl-tRNA synthetase.

Area of Science:

• Biochemistry
• Molecular Biology
• Parasitology

Background:

• Aminoacyl-tRNA synthetases (aaRSs) are essential for protein synthesis and are explored as antimicrobial targets.
• Arginyl-tRNA synthetase from Trypanosoma cruzi (TcArgRS) possesses a unique insertion absent in human counterparts, making it a potential drug target.

Purpose of the Study:

• To perform a preliminary characterization of TcArgRS using biophysical, biochemical, and bioinformatics approaches.
• To investigate the structural features and substrate specificity of TcArgRS.

Main Methods:

• Protein expression in E. coli and validation of in-vitro enzymatic activity.
• Analysis of DTNB kinetics, Circular Dichroism (CD) spectra, and ligand-binding studies using intrinsic tryptophan fluorescence.
• In silico methods for determining substrate binding.

Main Results:

• TcArgRS exhibits in-vitro enzymatic activity and can discriminate between L-arginine and its analogues.
• L-canavanine and L-thioarginine showed notable activation, indicating specific substrate interactions.
• Structural features were elucidated using biophysical techniques in the absence of crystal structures.

Conclusions:

• TcArgRS possesses unique characteristics that differentiate it from its human homolog.
• The study provides a foundation for developing targeted small compounds against TcArgRS for Chagas disease treatment.