Abstract

  The prevalence of fungal pathogenicity in the agricultural industry poses enormous hazards toward the world population. Preventative measures have thus far been unsuccessful, underscoring the need for new fungicide research. Cdc14 is a protein tyrosine phosphatase (PTP) that is critical for cell cycle regulation and virulence in a variety of fungal species. In this study, we investigate the enzymatic properties of Cdc14 in Fusarium oxysporum, a soilborne plant pathogen that causes a pernicious vascular wilt disease called Fusarium Wilt. By analyzing the catalytic mechanisms of FoCdc14, we identified optimal characteristics for targeted inhibitor development. Our enzyme underwent multiple stages of biochemical and computational analyses to extract data on its specificity, including inhibitor screenings both In vitro and In silico. I_C50 values and reversibility mechanisms were also tested using para-nitrophenyl phosphate (pNPP) to determine optimal binding properties for multiple peptide substrates. The integration of data from all tested parameters was then used to identify a baseline inhibitor for further optimization. By applying modifications, we were able to create an optimized inhibitor with a binding affinity increase of nearly 150%. These modifications included the addition of functional groups that maximized intermolecular interactions at the FoCdc14 binding site around residues Cys337 and Arg343. Throughout this process, we confirmed the conservation of FoCdc14’s enzyme kinetics and catalytic specificity to other Cdc14 orthologs. Because of such conservation, this novel inhibitor holds great potential to counteract virulence in F. oxysporum and other fungi, possibly paving the path for potent new fungicides. 

Keywords: F. Oxysporum; Cdc14; Inhibition Mechanism; Enzyme Kinetics; Molecular Docking; Substrate Specificity; Protein-Drug Interaction; Comparative Modeling; Ligand Optimization

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Citation

Citation: Sia Cho, Darrell Fan and Harry G. Heiberger. “A Novel Mechanism for the Target-Based Inhibition of Cdc14 Phosphatase Activity in F. Oxysporum Through Analysis of Catalytic Specificity and Enzyme Kinetics". Acta Scientific Medical Sciences 4.2 (2020): 149-164.

Copyright

Copyright: © 2020 Sia Cho, Darrell Fan and Harry G. Heiberger. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.