Polypeptide sequences for inducing recombinant protein bodies are described. The sequences comprise a polyproline II (PPII) structure and/or a proline-rich sequence between two cysteine residues on either end. Recombinant protein bodies are useful for protein production because they allow for simple and efficient purification of high quantities of recombinant protein. In addition, other methods of using recombinant protein bodies, for example, in vaccination and food products, are also described.