PR39 propeptide

A proline-arginine-rich peptide antibiotic. PR39 inhibits DNA and protein synthesis and the degradation of HIF-1α. It has been reported to bind to the α7 subunit of the 26S proteasome, blocking degradation of the NK-κB inhibitor, IκBα by the ubiquitin-proteasome pathway without affecting overall proteasome activity. More recent studies have demonstrated it to be an efficient inhibitor of all activities of the 20S proteasome.