Understanding the stereospecific interactions of 3-deoxyphosphatidylinositol derivatives with the PTEN phosphatase
Qin Wang1, Yang Wei, Madhusoodanan Mottamal
1Department of Chemistry, Boston College, Merkert Chemistry Center, Chestnut Hill, MA 02467, USA.
Abstract:
PTEN is an important control element of PI3K/AKT signaling involved in controlling the processes of embryonic development, cell migration and apoptosis. While its dysfunction is implicated in a large fraction of cancers, PTEN activity in the same pathway may also contribute to metabolic syndromes such as diabetes. In those cases, selective inhibitors of PTEN may be useful. A new class of chiral PTEN inhibitors based on the 3-deoxy-phosphatidylinositol derivatives was recently identified (Wang et al. [17]). However, lack of detailed understanding of protein-ligand interactions has hampered efforts to develop effective agonists or antagonists of PTEN. Here, we use computational modeling to characterize the interactions of the diverse 3-deoxyphosphatidylinositol inhibitors with the PTEN protein. We show that, while each of the compounds binds with the inositol headgroup inserting into the proposed active site of the PTEN phosphatase domain, hydrogen bonding restrictions lead to distinct binding geometries for ligand pairs of opposite chirality. We furthermore demonstrate that the binding modes differ primarily in the orientation of acyl tails of the ligands and that the activity of the compounds is primarily controlled by the effectiveness of tail-protein contacts. These findings are confirmed by binding affinity calculations which are in good agreement with experiment. Finally, we show that while more potent d-series ligands bind in a manner similar to that of the native substrate, an alternate hydrophobic pocket suitable for binding the opposite chirality l-series inhibitors exists, offering the possibility of designing highly selective PTEN-targeting compounds.
Insights
Computational modeling reveals distinct binding modes for chiral PTEN inhibitors. Understanding these interactions, particularly tail orientation, is key to designing selective PTEN-targeting drugs for cancer and diabetes.
Area of Science:
- Biochemistry
- Molecular Biology
- Computational Chemistry
Background:
- PTEN is a critical regulator of PI3K/AKT signaling, impacting embryonic development, cell migration, apoptosis, and metabolic syndromes like diabetes.
- PTEN dysfunction is linked to numerous cancers, making it a target for therapeutic intervention.
- Selective PTEN inhibitors are sought after, but a lack of detailed protein-ligand interaction knowledge hinders development.
Purpose of the Study:
- To computationally characterize the interactions between diverse 3-deoxy-phosphatidylinositol inhibitors and the PTEN protein.
- To elucidate how chirality influences PTEN inhibitor binding modes and activity.
- To identify potential strategies for designing highly selective PTEN-targeting compounds.
Main Methods:
- Computational modeling was employed to analyze PTEN-ligand interactions.
- Binding geometries and orientations of acyl tails were investigated.
- Binding affinity calculations were performed and compared with experimental data.
Main Results:
- All compounds bind with their inositol headgroup in the PTEN active site.
- Chirality dictates distinct binding geometries due to hydrogen bonding restrictions.
- Ligand acyl tail orientation and tail-protein contacts are primary determinants of compound activity.
- Potent d-series ligands mimic native substrate binding, while l-series inhibitors utilize an alternate hydrophobic pocket.
Conclusions:
- Computational modeling provides insights into chiral PTEN inhibitor binding modes.
- The orientation and contacts of ligand acyl tails significantly influence inhibitor efficacy.
- The existence of distinct binding pockets for different chiralities offers opportunities for developing highly selective PTEN inhibitors for therapeutic applications.
More Related Videos
Related Concept Videos
01:42Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
01:20The JAK-STAT Signaling Pathway
02:54Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
02:54Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
01:22PI3K/mTOR/AKT Signaling Pathway
01:11IP3/DAG Signaling Pathway