Insights into the selective mechanism of PDE2/9a inhibitors from silico aspects.

The selective design of competitive enzyme inhibitors is an extremely difficult task but necessary work for certain types of systems, such as the phosphodiesterase (PDE) system addressed in this article. In the PDE family, PDE2A and PDE9 respectively target the central nervous system and heart failure, and share many conserved amino acids at their binding sites. Therefore, gaining a deep understanding of the selective mechanisms of PDE2A/9A is crucial for designing highly selective drugs. In this study, various computer-aided drug design (CADD) methods, including molecular docking, molecular dynamics simulations (MD), and binding free energy calculations, are employed to explore the selective mechanisms of PDE2A/9A. Overall, our research results indicate a selective design strategy for PDE2A, which involves incorporating hydrophobic or aromatic moieties into the molecular structure to better accommodate the hydrophobic pocket of PDE2A. Additionally, it is recommended to introduce functional groups capable of forming connections with selective residues, such as Phe830 and Gln812 for PDE2A, or Ala452 and Tyr424 for PDE9A, to enhance the selectivity of inhibitors targeting PDE2A/9A. This achievement is anticipated to pave the way for the development of innovative and selective small molecules targeting PDE2A/9A.Communicated by Ramaswamy H. Sarma.

Insights into ß3-adrenoceptor agonism through comprehensive in silico investigation.

Research onß3-AR, the new member of the adrenoceptor family, is in its infancy and few ß3-AR agonists have been approved for marketing to date. Meanwhile, ß3-AR exhibited obvious species differences in pharmacological properties, such as between human and animals, however, the 3D structure of human ß3-AR has not been published, which makes it difficult to understand the interaction between human ß3-AR and its agonists. Herein, binding patterns of ß3-AR agonists are explored starting from the Alphafold predicted structural model, and the obtained model was optimized by using molecular dynamics simulations. Moreover, the human ß3-AR and its agonists were subjected to molecular docking, dynamics simulations, binding free energy calculations and pharmacophore modeling to elucidate the characteristics of human ß3-AR activity pockets and agonist conformational relationships, including a hydrophobic group, a positively charged group as well as two hydrogen-bonded donors, which provide comprehensive insights into the interactions between human ß3-AR and its agonists.

Selectivity mechanism of BCL-XL/2 inhibition through in silico investigation.

The BCL-XL protein is among the most important members of the anti-apoptotic subfamily of the BCL-2 protein family, and is currently a promising new target for anti-tumor drug research. However, the BCL-XL/2 proteins have similar structures and functions, which could lead to undesirable side effects because of inhibitors that can bind to both BCL-XL and BCL-2. Therefore, it is crucial to expound on the structural basis of the selective mechanism towards BCL-XL/2 inhibition. In the current study, we employed hybrid computational methods including molecular docking and dynamics simulation, MM/GBSA energy calculation, alanine scanning mutagenesis and Hirshfeld surface analysis to comprehensively reveal the selectivity mechanism towards BCL-XL/2 from multiple perspectives, revealing the significant effects of the BCL-XL residues SER106 and LEU108 as well as the BCL-2 residue ASP103 on the inhibitory selectivity. Overall, our findings provide useful references for the rational design of BCL-XL/2 selective inhibitors with better affinity.