Zinc binding in HDAC inhibitors: a DFT study.

Area of Science:

• Medicinal Chemistry
• Computational Chemistry
• Biochemistry

Background:

• Histone deacetylases (HDACs) are crucial drug targets for cancer and other diseases.
• Current HDAC inhibitors often utilize hydroxamic acids, posing developmental challenges.
• Exploring alternative chemical functionalities is essential for practical drug design.

Purpose of the Study:

• To investigate the binding modes and affinities of various functionalities in a model HDAC active site using DFT.
• To understand the role of hydroxamic acid protonation and zinc binding in HDAC inhibition.
• To guide the development of novel, non-hydroxamic acid HDAC inhibitors.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of binding modes and free energies of binding for diverse chemical groups.
• Investigation of protonation states and pKa values relevant to zinc binding.

Main Results:

• DFT calculations elucidated binding interactions of non-hydroxamic acid functionalities.
• The protonation state of hydroxamic acids significantly influences binding affinity.
• The pKa of zinc-binding groups is critical for effective HDAC inhibition.

Conclusions:

• Hydroxamic acids present limitations for practical drug development.
• Optimizing the pKa for zinc binding is paramount for designing potent HDAC inhibitors.
• This study provides a framework for developing novel, non-hydroxamic acid HDAC inhibitors.