Ledipasvir is a direct-acting antiviral agent used to treat specific hepatitis C virus (HCV) infections in combination with other antiviral agents. Hepatitis C virus lipoviroparticles enter target hepatocytes via receptor-mediated endocytosis. The lipoviroparticles attach to LDL-R and SR-B1, and then the virus binds to CD81 and subsequently claudin-1 and occludin, which mediate the late steps of viral entry. The virus is internalized by clathrin-dependent endocytosis. RNA is released from the mature Hepatitis C virion and translated at the rough endoplasmic reticulum into a single Genome polyprotein. The genome polyprotein is cleaved by host and viral proteases into 10 viral proteins. The nucleocapsid protein core and the two envelope proteins E1 and E2 form the N terminus of the polyprotein and are the structural components of HCV virions. The precursor also gives rise to the viroporin p7 and six non-structural (NS) proteins. Ledipasvir is an inhibitor of the Hepatitis C Virus (HCV) Nonstructural protein 5A required for viral RNA replication and assembly of HCV virions. The exact mechanism of this protein is unknown. Although its exact mechanism of action is unknown, it is postulated to prevent hyperphosphorylation of NS5A which is required for viral production. Viral RNA replication complexes localize to lipid raft-containing, detergent-resistant membranes created by the viral protein NS4B. For full viral replication and maturation, replication complexes need to be in close proximity to lipid droplets, which requires the protein nonstructural protein 5A. Without the Lipid Droplet due to inhibition of nonstructural protein 5A, full viral RNA replication is unable to occur. Envelope glycoproteins are acquired through budding into the endoplasmic reticulum lumen. The immature, non-infective virions are released via the cellular golgi apparatus.

Ledipasvir Pathway References