Study On Molecular Docking Between The Extracellular Portion Of Hab18G/Cd147 And Peptide Antagonist

Our country is a high prevalent area for hepatitis B, which causes liver cirrhosis and hepatocellular carcinoma. And it has been a severe social problem. Hepatocellular carcinoma-associated antigen HAb18G/CD147 can stimulate human fibroblasts to secrete matrix metalloproteinase (MMPs), which can excessively degrade basement membrane and cell stroma, conducive to tumor cell invasiveness and metastasis. It is a novel anti-tumor metastasis method to find out the effective HAb18G/CD147 antagonistic peptides which inhibit effector cell from secreting MMPs, by blocking HAb18G/CD147 in the upstream.At present, the researches regarding HAb18G/CD147 as the target, design, screening and synthesis of its peptide antagonists by biotechnology and biomedical experimental means to inhibit metastasis of liver cancer cell are common. While simulating and calculating the specific site information of protein-protein interaction through bioinformatics methodology combined with computer algorithms is relatively rare.Following this theme, we simulated the three-dimensional crystal structure of the receptor by using Molecular Dynamics (MD), and then make the receptor (the extracellular portion of HAb18G/CD147) dock with the ligand (12 peptide that owns the function of antagonizing the invasion and metastasis of liver cancer cells) by the System for Molecular Docking and Energy Analysis (SMDEA1.0) software developed by our researching group. Ultimately, the optimal docking structure was gained through the three stages below:pre-scoring, empirical binding free energy function scoring and results clustering for the preliminary docking results. After calculation and analysis on the optimal docking structure by SMDEA1.0, the binding region and specific active interaction sites of the Receptor-Ligand complex were found.The results of the research indicate that, amino acid residues on receptor interacted with ligand were I120-D122, D125, G159, Q160,1175, T177; while amino acid residues on ligand interacted with receptor were Y1, F3, H4, W8, Pll. Information of Interface Residue Pairing Preferences (RP) and specific energy items between residue-residue on the binding region were also calculated in this artical, in order to provide theoretical guidance and reference to drug design of peptide antagonists against hepatocellular carcinoma based on the three-dimensional crystal structure of the extracellular portion of HAb18G/CD147.