HSV-1 Glycoprotein D Inhibitors

Chemical inhibitors of herpes simplex virus type 1 (HSV-1) Glycoprotein D function by disrupting various stages of the viral entry process into host cells. N-docosanol exhibits its inhibitory action by inserting its aliphatic chain into the viral envelope, which interferes with the structural integrity of Glycoprotein D, essential for the virus's attachment and entry. This disruption hampers the ability of the virus to fuse with cellular membranes, a critical step for the initiation of an infection. Similarly, WAY-150138 targets the fusion step, but it acts more specifically by blocking Glycoprotein D's ability to facilitate the fusion of the viral envelope with the host cell membrane. BILS 45 BS also hampers entry, but rather than acting on the virus directly, it inhibits the interaction between Glycoprotein D and the herpes simplex virus entry mediator, a cellular receptor necessary for the virus to gain entry into the cell.

Furthermore, several inhibitors affect Glycoprotein D indirectly by targeting viral replication, which is essential for the production of Glycoprotein D. Foscarnet binds to the pyrophosphate binding site of the viral DNA polymerase, preventing the replication of viral DNA and, consequently, the synthesis of viral proteins, including Glycoprotein D. Nucleoside analogs such as Idoxuridine, Acyclovir, Valacyclovir, Penciclovir, Famciclovir, Trifluridine, Brivudine, and Sorivudine all function by disrupting viral DNA synthesis. They are incorporated into the growing viral DNA chain during replication, which leads to premature termination. This action significantly decreases the production of new virions, which in turn reduces the availability of Glycoprotein D for mediating the entry of the virus into new host cells. By impairing the ability of HSV-1 to replicate, these compounds indirectly limit the functional presence of Glycoprotein D, thereby inhibiting the initial steps of viral infection.