Analysis of Compounds That Interfere with Herpes Simplex Virus–Host Receptor Interactions Using Surface Plasmon Resonance

Abstract

The entry of herpes simplex virus into host cells involves a complex series of events that require concerted inputs from multiple HSV glycoproteins. Among these glycoproteins, the gD protein of HSV-1 and HSV-2 plays an important role for host receptor binding and membrane fusion. In the present study, we evaluated the ability of different sulfated saccharides to interfere with gD-host receptor (HVEM) interactions using our recently reported molecular assay (Gopinath, S. C. B.; Hayashi, K.; Kumar, P. K. R. J. Virol. 2012, 86, 6732-6744). Initially, we tested the ability of heparan sulfate to interfere with the HVEM-HSV-1 gD interaction and found that heparan sulfate is able to interfere efficiently, with an apparent EC50 of 2.1 μM. In addition, we tested different synthetic sulfated polysaccharides and natural sulfated polysaccharides from an edible alga, Sargassum horneri , after fractionation into different sizes and sulfate and uronic acid contents. Six polysaccharides isolated from S. horneri were found to efficiently interfere with the HVEM-gD interaction. Three others caused moderate interference, and five caused weak interference. These results were confirmed with plaque assays, and good agreement was found with the results of the SPR assay for the identification of compounds that interfere with HVEM-HSV-1 gD binding. These studies suggest that our molecular assay based on surface plasmon resonance is not only useful for the analysis of viral-host protein interactions but is also applicable for the routine screening of compounds to identify those that interfere with the first step of viral entry, thus facilitating the rapid development of novel antiviral compounds that target HSV.

Sargassum horneri methanol extract rescues C2C12 murine skeletal muscle cells from oxidative stress-induced cytotoxicity through Nrf2-mediated upregulation of heme oxygenase-1

“…Among them, Sargassum horneri (Turner) C. Agardh, an edible brown alga, is usually found in the coastal seas of Korea and Japan. Generally, S. horneri demonstrates antivirus [ 14 - 16 ], antioxidant [ 17 , 18 ], and anticoagulant activities [ 19 ], and preventative effects on bone loss by stimulating osteoblastic bone formation [ 20 ]. The protective actions of S. horneri against ultra violet (UV) A-induced damage have been reported; in particular, the chromene compound isolated from S. horneri shields human dermal fibroblasts from UV A-induced oxidative stress [ 21 , 22 ].…”

Systematic screening of viral entry inhibitors using surface plasmon resonance

“…weakly. 45 The polysaccharides that efficiently interfered with the gD-HVEM interaction were also found to be efficient inhibitors of HSV-1 replication in plaque assays. 45 These analyses show that sulfated polysaccharides isolated from an edible alga, S. horneri, efficiently inhibit the HSV-1 gD-HVEM interaction, most likely by binding to the gD of HSV-1.…”

“…45 The polysaccharides that efficiently interfered with the gD-HVEM interaction were also found to be efficient inhibitors of HSV-1 replication in plaque assays. 45 These analyses show that sulfated polysaccharides isolated from an edible alga, S. horneri, efficiently inhibit the HSV-1 gD-HVEM interaction, most likely by binding to the gD of HSV-1. Molecular assays based on SPR are suitable for the screening of a wide range of compounds, including sulfated glycans and other specific inhibitors such as aptamers, to identify inhibitors that target the initial phase of HSV infection and the interaction of viral glycoproteins with host cell receptors.…”

“…A total of 14 natural polysaccharides were isolated, fractionated, and tested for their ability to interfere with gD‐HVEM interactions using both our molecular assay and the plaque assay. Among the evaluated polysaccharides, 6 were found to interfere efficiently, 3 moderately, and 5 weakly . The polysaccharides that efficiently interfered with the gD‐HVEM interaction were also found to be efficient inhibitors of HSV‐1 replication in plaque assays .…”

“…The ligand surface can be regenerated by removing both analyte or analyte‐competitor complex step 3 in Figure C. A number of inhibitors have been analyzed using indirect assays, including small molecules and macromolecules …”