Selectivity Mechanism of ATP-Competitive Inhibitors for PKB and PKA
Ke Wu1, Jingzhi Pang1, Dong Song1
1State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai, 200240, China.
Abstract:
Protein kinase B (PKB) acts as a central node on the PI3K kinase pathway. Constitutive activation and overexpression of PKB have been identified to involve in various cancers. However, protein kinase A (PKA) sharing high homology with PKB is essential for metabolic regulation. Therefore, specific targeting on PKB is crucial strategy in drug design and development for antitumor. Here, we had revealed the selectivity mechanism for PKB inhibitors with molecular dynamics simulation and 3D-QSAR methods. Selective inhibitors of PKB could form more hydrogen bonds and hydrophobic contacts with PKB than those with PKA. This could explain that selective inhibitor M128 is more potent to PKB than to PKA. Then, 3D-QSAR models were constructed for these selective inhibitors and evaluated by test set compounds. 3D-QSAR model comparison of PKB inhibitors and PKA inhibitors reveals possible methods to improve the selectivity of inhibitors. These models can be used to design new chemical entities and make quantitative prediction of the specific selective inhibitors before resorting to in vitro and in vivo experiment.
Insights
Selective PKB inhibitors show higher binding affinity to PKB than PKA due to distinct interactions. This research aids in designing targeted cancer therapies by understanding inhibitor selectivity mechanisms.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Protein kinase B (PKB) is a key regulator in the PI3K pathway, often dysregulated in cancers.
- Protein kinase A (PKA), highly homologous to PKB, plays a vital role in metabolic regulation.
- Targeting PKB specifically is crucial for developing effective antitumor drugs.
Purpose of the Study:
- To elucidate the selectivity mechanism of PKB inhibitors against PKA using computational methods.
- To develop 3D-QSAR models for predicting the potency and selectivity of PKB inhibitors.
- To guide the design of novel, selective PKB inhibitors for cancer therapy.
Main Methods:
- Molecular dynamics simulations were employed to analyze inhibitor-protein interactions.
- 3D-Quantitative Structure-Activity Relationship (3D-QSAR) models were constructed and validated.
- Comparative analysis of inhibitor interactions with PKB and PKA was performed.
Main Results:
- Selective PKB inhibitors form more hydrogen bonds and hydrophobic contacts with PKB than with PKA.
- The inhibitor M128 demonstrated higher potency against PKB compared to PKA, consistent with simulation findings.
- Validated 3D-QSAR models provide a quantitative basis for predicting inhibitor selectivity.
Conclusions:
- Understanding the specific binding interactions is key to designing selective PKB inhibitors.
- 3D-QSAR models can accelerate the discovery of potent and selective antitumor agents.
- This study provides a framework for rational drug design targeting PKB.
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