Targeted Protein Interactions Driven by Hybrid Vanadium-Oxo Clusters in Solution

Area of Science:

• Bioinorganic Chemistry
• Supramolecular Chemistry
• Biocatalysis

Background:

• Polyoxometalates (POMs) are versatile metal-oxo clusters with catalytic potential.
• Hybrid POMs offer unique properties for interacting with biological systems.
• Modulating protein function with inorganic catalysts is an emerging field.

Purpose of the Study:

• To investigate the binding interactions between a specific hybrid vanadium-oxo cluster (V₆-OH) and hen egg white lysozyme (HEWL).
• To elucidate the structural and energetic aspects of this protein-cluster interaction.
• To explore the implications for biocatalysis and therapeutic applications.

Main Methods:

• Solution-based studies using ⁵¹V NMR spectroscopy, cyclic voltammetry (CV), fluorescence spectroscopy, circular dichroism (CD) spectroscopy, UV-vis spectroscopy, and isothermal titration calorimetry (ITC).

Main Results:

• Confirmed spontaneous and specific binding of V₆-OH to HEWL with high affinity (negative Gibbs free energy).
• Observed significant changes in ⁵¹V NMR line widths and electrochemical potential upon binding.
• Demonstrated minimal perturbation of HEWL secondary structure by CD spectroscopy, indicating structural integrity.

Conclusions:

• Hybrid hexavanadates exhibit strong and selective binding to proteins like HEWL.
• The observed interactions facilitate localized redox activities, crucial for targeted biocatalysis.
• These findings support the potential of V₆-OH for therapeutic applications.