Abstract: Objective To isolate sequences from a phage display 7-mer peptide library, synthesize keratinocyte growth factor（KGF） bioactive peptide from the isolated sequences and to evaluate the effects of KGF bioactive peptide on epidermal cell proliferation. Methods Using monoclonal anti-human KGF antibody as the target, a phage display 7-mer peptide library was screened and target sequences were isolated. The sequences were then modified to generate KGF bioactive peptides. Immunofluorescence assay was performed to evaluate the binding activity of KGF peptides on epidermal cells.CCK-8 was used to detect the effects of KGF bioactive peptide on epidermal cell proliferation. RT-PCT and Western-blot were used to detect the expression of KGF receptor of epithelial cells. Results Two peptides similar to KGF was isolated from a phage display 7-mer peptide library and then modified to generate two KGF bioactive peptides. KGF bioactive peptides were then purified to reach a purity of 98%. The C terminal of KGF bioactive peptides was closed, and the N terminal was labeled with rhodamine dye laser. KGF bioactive peptides were able to combine with the epidermal cells showed by Immunofluorescence assay. CCK-8 test results showed that compared with the control group, the two KGF bioactive peptides promoted epidermal cell proliferation in a dose-dependent manner. RT-PCR and Western-blot test results showed two KGF bioactive peptidegroup enhanced the expression of KGFR on epidermal cells. Conclusion KGF bioactive peptides can be synthesized based on sequences screened from phage display peptide library. KGF bioactive peptides are capable of combining with KFGR, enhancing the expression KGFR, and thereby promoting the proliferation of epidermal cells. The results are expected to help promoting wound healing.

Key words: Phage display 7-mer peptide library, Keratinocyte growth factor, Bioactive peptide, Epidermis cell, Wound healing