Nkl71–100 peptide

Nkl71–100 is the peptide from aa residue 71 to 100 that comprises the membrane-lytic region of the turbot NK-lysin. Nkl71–100 exerts strong antiviral activity against spring viremia of carp virus (SVCV) by inhibiting not only the binding of viral particles to host cells, but also the fusion of virus and cell membranes, which requires a low pH context. Nkl71–100 could interfere in the replicative cycle of viruses whose entry into the host cell implies a process of receptor-mediated endocytosis, followed by another fusion step to the lysosome membrane at acidic pH. Nkl71–100 was able to induce the release of the vesicle content, which was significantly higher at pH 3, in a concentration-dependent manner. Nkl71–100 is at least (since potential inhibitory effects at late steps of infection cannot be discarded yet) affecting viral replication at an early stage in which virus-cell interactions are implicated, most probably at membrane levels. Nkl71–100 might still be playing an inhibitory role in other subsequent related mechanisms involving the same actors, such as the virus-cell membrane fusion.