Unravelling phosphorylation-induced impacts on inhibitor-CDK2 through multiple independent molecular dynamics simulations and deep learning

Phosphorylation plays an important role in the activity of CDK2 and inhibitor binding, but the corresponding molecular mechanism is still insufficiently known. To address this gap, the current study innovatively integrates molecular dynamics (MD) simulations, deep learning (DL) techniques, and free energy landscape (FEL) analysis to systematically explore the action mechanisms of two inhibitors (SCH and CYC) when CDK2 is in a phosphorylated state and bound state of CyclinE. With the help of MD trajectory-based DL, key functional domains such as the loops L3 loop and L7 are successfully identified. The results of FEL analysis show that the binding of CyclinE significantly enhances conformational stability of key functional regions of CDK2 (such as the L3 loop, L7 loop, and αC helix), while phosphorylation modification increases conformational diversity of the CDK2-related system. Further verification by quantum mechanics/molecular mechanics-generalized Born surface area (QM/MM-GBSA) calculations shows that binding of CyclinE can enhance the binding ability of inhibitors, while phosphorylation weakens this binding effect. Residue-based free energy estimation reveals the hot spot regions of inhibitor-CDK2 binding, providing crucial target information for structure-based drug design. This study provides theoretical foundations for the development of highly selective CDK2 inhibitors and might be of great significance for cancer targeted therapy.