I have a question about cloning short peptides into plasmid/phagemid.

I want to modify the pCom8 vector (Addgene). pCom8 contains two cloning sites - for cloning heavy (between the restriction sites XhoI and SpeI) and light chain (between the restriction sites SacI and XbaI) of antibodies.

In my experiment, I would like to insert a short immunogenic peptide (9 AK) between restriction sites XhoI and SpeI so that it will be fused to pVIII. I do not need the second cloning cassette.

I read on Addgene site about pCom8: both cloning cassettes have a pelB leader sequence, the light chain and heavy chain-geneVIII fusion product assemble in the periplasm to form the Fab fragment.

-> The second cloning cassette codes for two amino acids (valine in serine). In the case of fusion of the two cloning cassettes, could these two amino acids disturb the immunogenicity of the peptide??

I decided to remove the second cloning cassette (restriction enzymes EcoICRI and Eco0109I). However also in this case after the pelB leader sequence there are three remaining nucleotides (AK glu).

-> Will these AK also combine with immunogenic peptide-geneVIII fusion product??

What actually happens to restriction enzyme sites during phage dispay - do they interfere with the fusion of the coat protein with the foreign protein or do they have no effect??