Situating the phosphonated calixarene-cytochrome C association by molecular dynamics simulations.

Area of Science:

• Biochemistry
• Computational Chemistry
• Structural Biology

Background:

• Protein-calixarene interactions are crucial for molecular recognition, drug delivery, and protein inhibition.
• Bio-supramolecular chemistry governs these interactions, often requiring computational analysis.
• Molecular dynamics (MD) simulations offer insights into these complex binding mechanisms.

Purpose of the Study:

• To investigate the electrostatically driven association between a phosphonated calix-[4]-arene and cytochrome-C using MD simulations.
• To identify binding sites and analyze the impact of binding on protein dynamics.
• To compare the binding of phosphonated calixarenes with analogous sulfonato calixarenes.

Main Methods:

• All-atom, explicit-solvent molecular dynamics simulations were employed.
• The simulations focused on the interaction between a phosphonated calix-[4]-arene and cytochrome-C.
• Comparative analysis with sulfonato calixarenes was performed.

Main Results:

• Two binding sites for the phosphonated calix-[4]-arene on cytochrome-C were identified, consistent with X-ray crystallography data.
• The binding significantly influenced the overall dynamics of the protein.
• The study provided a basis for comparing different calixarene derivatives as potential 'molecular glues'.

Conclusions:

• The research demonstrates the utility of MD simulations in understanding protein-calixarene binding.
• The findings support the development of in silico tools for predicting binding sites and guiding crystallization.
• The orientation of calixarenes (endo/exo) is a key factor in their binding specificity to proteins.