title: Using protein-based motifs to stabilize peptides.
abstract: While the use of synthetically derived novel inhibitor peptides as a source of new therapeutics for medicine remains incredibly promising, there is a major problem with implementing this technology, as many synthetic peptides have proven to be unstable and are degraded by peptidases in the host cell. In this study, we have investigated methods by which peptides can be stabilized using protein-based motifs in order to prevent the action of peptidases. Using an in vivo approach our laboratory developed to screen for synthetic peptides which can inhibit the growth of Escherichia coli, we found that protecting the amino or carboxyl terminus of the peptides via fusion to the very stable Rop protein, or the incorporation of two proline residues, increased the frequency at which potent inhibitor peptides could be isolated. Using an in vitro degradation assay in which extracts from several different cell types were tested, we demonstrated that peptides stabilized with multiple proline residues were more resistant to degradation than peptides stabilized by amidation or acetylation, two approaches that are routinely utilized to improve the stability of peptide drugs.
authors.affiliation: Department of Biological and Agricultural Engineering, Center for Molecular BioEngineering, University of Georgia, Athens, GA 30602, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Walker
authors.forename: R K
authors.initials: RK
authors.lastname: Altman
authors.forename: J W
authors.initials: JW
authors.lastname: Warren
authors.forename: E
authors.initials: E
authors.lastname: Altman
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000138:chemical synthesis* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D002457:Cell Extracts; D004355:Drug Stability; D010450:Endopeptidases; D006207:Half-Life; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases; D019151:Peptide Library; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D011392:Proline / Q000737:chemistry*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002457:Cell Extracts; D019151:Peptide Library; D010455:Peptides; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C054243:Rop protein, ColE1 plasmid; D011392:Proline; D010450:Endopeptidases; D010447:Peptide Hydrolases