Journal: Biology
Article Title: Kukoamine B Inhibits EMT in Lung Adenocarcinoma Cells by Regulating Intracellular PD-L1-Mediated p65 Nuclear Translocation
doi: 10.3390/biology15050435
Figure Lengend Snippet: Binding Free Energy and Interface Analysis Unveils the Strong Binding Affinity of the PD-L1/p65 Complex. ( A , B ) A 3D visualization showing the interaction residues of PD-L1 (green) and p65 (cyan), with hydrogen bonds represented as solid magenta lines—the electrostatic surfaces of residues involved in hydrophobic interactions are also depicted; ( C ) LigPlot+ analysis illustrating the interactions between PD-L1 (chain A) and p65 (chain B), where hydrogen bonds are shown as green dashed lines, labeled with distances, and hydrophobic contacts are indicated by red arcs pointing toward the interacting residues; ( D ) bar chart displaying the contributions of various energetic components to the binding free energy of the PD-L1–p65 complex, as calculated using the MM/GBSA method, including components such as VDWAALS (van der Waals interactions), EEL (electrostatic interactions), EGB (polar solvent interactions), ESURF (non-polar solvation energy), GGAS (gas-phase energy: VDWAALS + EEL), and GSOLV (solvation energy: EGB + ESURF); ( E ) per-residue energy contributions for individual residues in the PD-L1–p65 complex, with the bar chart indicating the stabilization contributions (negative values) of each residue to the binding free energy (kcal/mol); ( F ) heat map illustrating per-residue energy contributions throughout the MD simulation, with residues from PD-L1 (chain A) and p65 (chain B) displayed, and a color scale ranging from blue (stabilizing contributions) to red (destabilizing contributions) providing insights into the interaction strength and stability across simulation frames; ( G ) Gibbs free energy landscape of the PD-L1–p65 complex, represented as a heat map of RMSD versus the radius of gyration (GYRATE), where blue regions correspond to low-energy, stable states and red regions indicate higher energy states; ( H ) Gibbs energy landscape focusing on specific residues within the PD-L1 (19F-132A) and p65 (296H-314K) domains, highlighting regions of significant stability; ( I ) detailed structural view of the binding interface between PD-L1 and Kukoamine B, with the Kukoamine B-binding residues on PD-L1 shown as electrostatic potential surfaces.
Article Snippet: In this study, the antibodies utilized were as follows: Normal Rabbit IgG (2729S) and p65 (8242S) rabbit monoclonal antibodies from CST; PD-L1/CD274 (28076-1-AP), E-cadherin (20874-1-AP), N-cadherin (22018-1-AP), Vimentin (10366-1-AP), Lamin B1 (12987-1-AP), GAPDH (10494-1-AP), and HRP Mouse Anti-Rabbit IgG Light Chain Specific (SA00001-7L) from Proteintech; Phospho-p65 (AF2006) from Affinity; and secondary antibody HRP Goat Anti-Rabbit IgG from Abclonal (AS014).
Techniques: Binding Assay, Labeling, Solvent, Residue