Hi Cuixia, I am old fashion. In silico, everything might work out great on a computer screen, but you will never know how peptides affect cells until you try them.

The "wet work" required of examining how peptides interact with cells is a quantum leap from what they do in computer models.    

You can initially do in silico studies on peptides to identify already reported bioactivity using   Peptide ranker and BIOPEP database and then perform molecular docking for followed by in vitro validation assays for the lead peptides.