Oligopeptides inhibit the ribonucleotide reductase of herpes simplex virus by causing subunit separation

It has recently been reported that a nonapeptide (H-Tyr-Ala-Gly-Ala-Val-Val-Asn-Asp-Leu-OH) identical in sequence to the last nine amino acid residues of RR2, the small subunit of herpes simplex virus (HSV) ribonucleotide reductase (E.C. 1.17.4.1; RR), can inhibit HSV RR activity in vitro. It has been postulated that this peptide acts by interfering with the interaction of the large subunit, RR1, and RR2, but direct demonstration of its mechanism of action has not been reported. We present data which show that the inhibition of HSV RR by this oligopeptide is due to induced subunit dissociation.