An Improved Comparative Docking Approach for Developing Specific Glycogen Phosphorylase Inhibitors Using Pentacyclic...

Area of Science:

• Computational chemistry and drug discovery
• Biochemistry and molecular biology

Background:

• Off-target effects in drug discovery are a major concern due to protein sequence and structural homology.
• Similar binding pockets across protein families lead to ligand cross-reactivity, necessitating early identification of off-targets.
• Glycogen phosphorylase inhibitors (GPi) face isoform specificity challenges between hepatic (hGP) and muscle (mGP) forms, impacting safety.

Purpose of the Study:

• To design and identify isoform-specific ligands for glycogen phosphorylase (GP).
• To address the cross-reactivity issue of GP inhibitors (GPi) between hepatic (hGP) and muscle (mGP) forms.
• To optimize drug leads for enhanced specificity and reduced side effects in early drug discovery.

Main Methods:

• A comparative molecular docking approach was employed.
• Ligands were designed based on chemical descriptors of the lig18 binding site in both hGP and mGP.
• Virtual docking was performed to evaluate ligand-target interactions and affinities.

Main Results:

• The optimized compound, lig18_7, demonstrated improved affinity for both hGP and mGP.
• Lig18_7 exhibited specificity by interacting with unique residues (Arg171, Asn172) in hGP.
• The comparative docking approach proved effective for developing isoform-specific ligands.

Conclusions:

• Comparative docking is a valuable strategy for designing isoform-specific drug candidates.
• This method can effectively mitigate cross-reactivity issues in drug discovery.
• Development of specific ligands for targets like glycogen phosphorylase (GP) can be significantly improved.