title: A recombinant allosteric lectin antagonist of HIV-1 envelope gp120 interactions.
abstract: The first, critical stage of HIV-1 infection is fusion of viral and host cellular membranes initiated by a viral envelope glycoprotein gp120. We evaluated the potential to form a chimeric protein entry inhibitor that combines the action of two gp120-targeting molecules, an allosteric peptide inhibitor 12p1 and a higher affinity carbohydrate-binding protein cyanovirin (CVN). In initial mixing experiments, we demonstrated that the inhibitors do not interfere with each other and instead show functional synergy in inhibiting viral cell infection. Based on this, we created a chimera, termed L5, with 12p1 fused to the C-terminal domain of CVN through a linker of five penta-peptide repeats. L5 revealed the same broad specificity as CVN for gp120 from a variety of clades and tropisms. By comparison to CVN, the L5 chimera exhibited substantially increased inhibition of gp120 binding to receptor CD4, coreceptor surrogate mAb 17b and gp120 antibody F105. These binding inhibition effects by the chimera reflected both the high affinity of the CVN domain and the allosteric action of the 12p1 domain. The results open up the possibility to form high potency chimeras, as well as noncovalent mixtures, as leads for HIV-1 envelope antagonism that can overcome potency limits and potential virus mutational resistance for either 12p1 or CVN alone.
authors.affiliation: Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA.
authors.forename: Karyn
authors.initials: K
authors.lastname: McFadden
authors.forename: Simon
authors.initials: S
authors.lastname: Cocklin
authors.forename: Hosahudya
authors.initials: H
authors.lastname: Gopi
authors.forename: Sabine
authors.initials: S
authors.lastname: Baxter
authors.forename: Sandya
authors.initials: S
authors.lastname: Ajith
authors.forename: Naheed
authors.initials: N
authors.lastname: Mahmood
authors.forename: Robin
authors.initials: R
authors.lastname: Shattock
authors.forename: Irwin
authors.initials: I
authors.lastname: Chaiken
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D016466:CHO Cells; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism; D037102:Lectins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D015704:CD4 Antigens; D002352:Carrier Proteins; D015699:HIV Envelope Protein gp120; D037102:Lectins; D010455:Peptides; D011993:Recombinant Fusion Proteins; C107733:cyanovirin N