title: Characterization of a heparan sulfate octasaccharide that binds to herpes simplex virus type 1 glycoprotein D.
abstract: Herpes simplex virus type 1 utilizes cell surface heparan sulfate as receptors to infect target cells. The unique heparan sulfate saccharide sequence offers the binding site for viral envelope proteins and plays critical roles in assisting viral infections. A specific 3-O-sulfated heparan sulfate is known to facilitate the entry of herpes simplex virus 1 into cells. The 3-O-sulfated heparan sulfate is generated by the heparan sulfate d-glucosaminyl-3-O-sulfotransferase isoform 3 (3-OST-3), and it provides binding sites for viral glycoprotein D (gD). Here, we report the purification and structural characterization of an oligosaccharide that binds to gD. The isolated gD-binding site is an octasaccharide, and has a binding affinity to gD around 18 microm, as determined by affinity coelectrophoresis. The octasaccharide was prepared and purified from a heparan sulfate oligosaccharide library that was modified by purified 3-OST-3 enzyme. The molecular mass of the isolated octasaccharide was determined using both nanoelectrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. The results from the sequence analysis suggest that the structure of the octasaccharide is a heptasulfated octasaccharide. The proposed structure of the octasaccharide is DeltaUA-GlcNS-IdoUA2S-GlcNAc-UA2S-GlcNS-IdoUA2S-GlcNH(2)3S6S. Given that the binding of 3-O-sulfated heparan sulfate to gD can mediate viral entry, our results provide structural information about heparan sulfate-assisted viral entry.
authors.affiliation: Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, USA. jian_liu@unc.edu
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Zach
authors.initials: Z
authors.lastname: Shriver
authors.forename: R Marshall
authors.initials: RM
authors.lastname: Pope
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Thorp
authors.forename: Michael B
authors.initials: MB
authors.lastname: Duncan
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Copeland
authors.forename: Christina S
authors.initials: CS
authors.lastname: Raska
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Roselyn J
authors.initials: RJ
authors.lastname: Eisenberg
authors.forename: Gary
authors.initials: G
authors.lastname: Cohen
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Linhardt
authors.forename: Ram
authors.initials: R
authors.lastname: Sasisekharan
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004187:Disaccharides / Q000737:chemistry; D019075:Electrophoresis, Capillary; D007313:Insecta; D007700:Kinetics; D008956:Models, Chemical; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D014466:Ultraviolet Rays; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004187:Disaccharides; D011134:Polysaccharides; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; C039447:glycoprotein D, Human herpesvirus 1