肺鳞癌靶点蛋白基质金属蛋白酶9靶向多肽的合成及验证OA

Objective To synthesize and verify a matrix metalloproteinase-9(MMP9)-targeting peptide for lung squamous cell carcinoma,aiming to develop a novel MMP9-targeting peptide.Methods The crystal structures of MMP9 and its ligand were obtained from the Protein Data Bank(PDB)and optimized using Molecular Operating Environment soft-ware.Molecular docking was performed to identify interaction sites between MMP9 and its ligand.Key residues(Tyr49,Ser50,and Asn55)were confirmed using the London dG scoring function(S score).A template peptide was selected and mutated,followed by protein-protein docking to screen six candidate peptides with the lowest S scores.After synthetic fea-sibility assessment,three candidate peptides were selected for synthesis along with the template peptide.The purity and structure of the four synthesized peptides were characterized by high-performance liquid chromatography(HPLC).Human lung squamous cell carcinoma cells(NCI-H226)were divided into five groups:SP-template peptide group,SP-1 peptide group,SP-2 peptide group,SP-3 peptide group,and control group(treated with MMP9 antibody and fluorescent pep-tide).Fluorescence images were acquired,and fluorescence intensity was analyzed using ImageJ software to evaluate the affinity of the candidate peptides for NCI-H226 cells.Results Four target peptides were successfully synthesized,with their structures validated by mass spectrometry and purity levels exceeding 95%.The fluorescence intensities of the SP-template peptide group,SP-1 peptide group,SP-2 peptide group,SP-3 peptide group,and control group were 1.48±0.15,1.14±0.12,1.85±0.07,0.68±0.20,and 1.00±0.13,respectively,with the SP-2 peptide group exhibiting significantly higher fluorescence intensity than all other groups(all P<0.05).Conclusions The novel MMP9-targeting peptide SP-2 was successfully synthesized.The synthesized peptide was verified to have the correct structure and high puri-ty,and it demonstrated high binding affinity toward human lung squamous cell carcinoma cells.