"Plasmids and methods for peptide display and affinity selection in rna bacteriophage virus-like particles". The present invention relates to a system and methods for controlling the display valence of peptides in virus-like particles (vlps), especially including vlps ms2. In this method, large amounts of wild-type coated proteins and low amounts of single chain dimer coated proteins may be produced from a single RNA. Valence is controlled in the production of immunogen (vaccine) by providing a system that allows the production of large amounts of wild-type coated proteins and low amounts of single-chain dimer-coated proteins can be produced from a single rna allowing adjustment Easy to display valence levels in vlps, especially vlps ms2 over a wide range from one, up to as much as 90 per particle. This facilitates the production of immunogens and vaccines, including vlps exhibiting low valence. nucleic acid constructs useful in expressing virus-like particles are disclosed comprising an ms2-coated polypeptide modified by the insertion of a heterologous peptide, wherein the heterologous peptide is displayed on the virus-like particle and encapsulates nirna ms2. nucleic acid constructs are also shown which are useful in expressing virus-like particles comprising a pp7-coated polypeptide modified by the insertion of a heterologous peptide, wherein the heterologous peptide is displayed on the virus-like particle and encapsulates the pp7 from mrna.patente de invenção: "plasmídeos e métodos para exibição de peptídeo e seleção de afinidade em partículas semelhantes a vírus de bacteriófagos de rna". a presente invenção refere-se a um sistema e a métodos para controlar a valência de exibição de pepídeos em particulas semelhantes a vírus (vlps), especialmente incluindo vlps ms2. neste método, grandes quantidades de proteínas revestidas do tipo selvagem e baixas quantidades de proteínas revestidas de dímero de cadeia única podem ser produzidas de um único rna. a valência é co
