RNase S complex bearing arginine-rich peptide and anti-HIV activity

Basic peptide‐mediated protein delivery into living cells is becoming recognized as a potent approach for the understanding of cellular mechanisms and drug delivery. We have prepared the conjugates of the S‐peptide (1–15) derived from RNase S with membrane‐permeable basic peptides, octaarginine and the human immunodeficient virus (HIV)‐1 Rev (34–50). The RNase S complexes, formed among these S‐peptide (1–15)–basic peptide conjugates and the S‐protein and having a dissociation constant in the range of 10−5 M, efficiently penetrated into the HeLa cells. These RNase S complexes exerted an anti‐HIV replication activity. The time‐of‐drug‐addition assay suggested that the site of action for these complexes would reside in the stages between the viral entry into the cells and reverse transcription. The present study exemplified the applicability of the arginine‐rich peptides to the intracellular targeting of non‐covalent protein complexes and supramolecular assemblies for the research in chemical and cellular biology. Copyright © 2004 John Wiley & Sons, Ltd.