Inhibition of prophage induction by synthetic pentapeptide

Six peptide chains different in length and number of sequences were synthesized by the continuous-flow solid-phase method. Their effects on prophage induction were tested. It was found that pentapeptide 1 H-Val-Val-Asn-Asp-Leu-OH, at a concentration of 25 micrograms/mL inhibited the spontaneous induction of prophage Lambda in E. coli strain W 3110(lambda) and phi RLZLS in R. leguminosarum (lysogenic local isolate) by 99.5% and 65.7%, respectively. Moreover, this concentration was also able to inhibit the replication of the developed phages in the indicator strains. It was suggested that this peptide may block the attachment site of the induced phages or inhibit Rec A Protease.