Peptide-compound cyclization method

A peptide compound-nucleic acid complex produced by a process comprising the steps of:

• (a) translationally synthesizing a noncyclic peptide compound having 9 to 13 amino acids and amino acid analogs in total to form a noncyclic peptide compound-nucleic acid complex in which the noncyclic peptide compound links to a nucleic acid sequence encoding the noncyclic peptide compound through a linker;
• and
• (b) cyclizing the noncyclic peptide compound of the complex translationally synthesized in Step (a) by an amide bond or a carbon-carbon bond to form a cyclic compound having a cyclic portion with 5 to 12 amino acid and amino acid analog residues in total,
• wherein the nucleic acid sequence has a spacer at the 3′-end,
• wherein the C-terminal of the noncyclic peptide compound forms a complex with the nucleic acid sequence through the spacer.