Structural Modification Of Antitumor Peptides And The Preliminary Evaluation Of Their Stability And Cytotoxicity

Objects:To design and synthesize a series of antitumor pro-peptides，which target on fibroblastactivated protein α. On one hand, it is expected that the modified antitumor pro-peptides willshow enhanced targeting ability in the purpose of increasing their therapy index; while on theother hand, the stability of all the designed polypeptides in serum will be improved，resulted inlonger half-life in serum. To make the modified antitumor polypeptides more drug-like.Methods:1. To synthesize YSL、YSV、LDV and YIGSR parent peptides by solid phase peptide synthesis(spps) based on Fmoc/t-Bu strategy. The parent peptides were modified in two ways: one isto change C-terminal carboxyl into amide; the other is to block N-terminal of the parentpeptides by a fragment, namely Z-GP, which is recognized specifically by FAP-. All theprepared peptide were purified by RP-HPLC.2. The stability of both parent peptides and modified antitumor oligopeptides were evaluated bymonitoring their changing concentration at scheduled time points using RP-HPLC method, inwhich each sample was dissolved in PBS、DMEM and serum and bathed at the temperatureof37℃respectively.3. Cytotoxicity of both parent peptides and modified antitumor oligopeptides were determinedby MTT assay respectively to evaluate their antitumor activity, and to evaluate whether ifZ-GP fragment blocks the anti-tumor activity of the parent peptides.Results:Successfully synthesized12oligopeptide. The Structure were Confirm by1H-NMR、13C-NMRand ESI-MS. Stability test show that modified antitumor oligopeptides were more stable thanParent peptides. MTT test indicated that modified YSL had stronger cytotoxicity than parentpeptide.