Synthesis of novel, multivalent glycodendrimers as ligands for HIV-1 gp120.
Multivalent neoglycoconjugates are valuable tools for studying carbohydrate-protein interactions. To study the interaction of HIV-1 gp120 with its reported alternate glycolipid receptors, galactosyl ceramide (GalCer) and sulfatide, galactose- and sulfated galactose-derivatized dendrimers were synthesized, analyzed as ligands for rgp120 by surface plasmon resonance, and tested for their ability to inhibit HIV-1 infection of CXCR4- and CCR5-expressing indicator cells. Four different series of glycodendrimers were made by amine coupling spacer-arm derivatized galactose residues, either sulfated or nonsulfated, to poly(propylenimine) dendrimers, generations 1-5. One series of glycodendrimers was prepared from the ceramide saccharide derivative of purified natural GalCer, and another was from chemically synthesized 3-(beta-D-galactopyranosylthio)propionic acid. Synthesis of 3-sulfogalactopyranosyl-derivatized dendrimers was accomplished using the novel compound, 3-(beta-D-3-sulfogalactopyranosylthio)propionic acid. The fourth series was made by random sulfation of the 3-(beta-D-galactopyranosylthio)propionic acid functionalized dendrimers. Structures of the carbohydrate moieties were confirmed by NMR, and the average molecular weights and polydispersities of the different glycodendrimers were determined using MALDI-TOF MS. Surface plasmon resonance studies found that rgp120 IIIB bound to the derivatized dendrimers tested with nanomolar affinity, and to dextran sulfate with picomolar affinity. In vitro studies of the effectiveness of these compounds at inhibiting infection of U373-MAGI-CCR5 cells by HIV-1 Ba-L indicated that the sulfated glycodendrimers were better inhibitors than the nonsulfated glycodendrimers, but not as effective as dextran sulfate.
Kensinger
Richard D
RD
Department of Biochemistry and Molecular Biology H171, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, USA.
Yowler
Brian C
BC
Benesi
Alan J
AJ
Schengrund
Cara-Lynne
CL
D000818:Animals; D002417:Cattle; D016264:Dextran Sulfate / Q000138:chemical synthesis / Q000378:metabolism; D005690:Galactose / Q000138:chemical synthesis / Q000378:metabolism; D006001:Glycoconjugates / Q000138:chemical synthesis* / Q000378:metabolism*; D015699:HIV Envelope Protein gp120 / Q000378:metabolism*; D008024:Ligands; D011956:Receptors, Cell Surface / Q000378:metabolism*
D006001:Glycoconjugates; D015699:HIV Envelope Protein gp120; D008024:Ligands; D011956:Receptors, Cell Surface; C033639:glycolipid receptor; D016264:Dextran Sulfate; D005690:Galactose