In vivo production of cyclic peptides for inhibiting protein-protein interaction
The present invention relates to methods and compositions utilizing inteins to generate libraries of cyclic peptides in vivo. The prevent invention also relates to methods for inhibiting protein-protein interaction.
1. A method comprising:
a) contacting a culture of cells with a nucleic acid library of fusion nucleic acids that each encode a fusion polyeptide comprising:
i) a C-terminal intein motif;
ii) a peptide; and
iii) an N-terminal intein motif,
wherein said fusion polypeptide produces a cyclic peptide when produced in a cell,
b) monitoring said cells for a change in ubiquitination of a molecule within a cell;
c) isolating a fusion nucleic acid that when introduced into said cell caused said change in ubiquitination of said molecule.
2. The method according to claim 1 , wherein said cyclic peptide inhibits ubiquitination of said molecule.
3. The method according to claim 1 , wherein said cyclic peptide increases ubiquitination of said molecule relative to ubiquitination of said molecule in other cells of said culture.
4. The method according to claim 1 , wherein said cells are mammalian cells.
5. The method according to claim 1 , wherein said nucleic acid library comprises a retroviral vector.