title: Modifications that stabilize human immunodeficiency virus envelope glycoprotein trimers in solution.
abstract: The functional unit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins is a trimer composed of three gp120 exterior glycoproteins and three gp41 transmembrane glycoproteins. The lability of intersubunit interactions has hindered the production and characterization of soluble, homogeneous envelope glycoprotein trimers. Here we report three modifications that stabilize soluble forms of HIV-1 envelope glycoprotein trimers: disruption of the proteolytic cleavage site between gp120 and gp41, introduction of cysteines that form intersubunit disulfide bonds, and addition of GCN4 trimeric helices. Characterization of these secreted glycoproteins by immunologic and biophysical methods indicates that these stable trimers retain structural integrity. The efficacy of the GCN4 sequences in stabilizing the trimers, the formation of intersubunit disulfide bonds between appropriately placed cysteines, and the ability of the trimers to interact with a helical, C-terminal gp41 peptide (DP178) support a model in which the N-terminal gp41 coiled coil exists in the envelope glycoprotein precursor and contributes to intersubunit interactions within the trimer. The availability of stable, soluble HIV-1 envelope glycoprotein trimers should expedite progress in understanding the structure and function of the virion envelope glycoprotein spikes.
authors.affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.forename: L
authors.initials: L
authors.lastname: Florin
authors.forename: M
authors.initials: M
authors.lastname: Farzan
authors.forename: P
authors.initials: P
authors.lastname: Kolchinsky
authors.forename: P D
authors.initials: PD
authors.lastname: Kwong
authors.forename: J
authors.initials: J
authors.lastname: Sodroski
authors.forename: R
authors.initials: R
authors.lastname: Wyatt
mesh_terms: D000595:Amino Acid Sequence; D001704:Biopolymers; D002499:Centrifugation, Density Gradient; D002845:Chromatography / Q000379:methods; D000077560:Enfuvirtide; D015686:Gene Products, env / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D015483:HIV Antibodies / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011233:Precipitin Tests; D019713:Receptors, CCR5 / Q000378:metabolism; D012995:Solubility
chemical_list: D001704:Biopolymers; D015686:Gene Products, env; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D010446:Peptide Fragments; D019713:Receptors, CCR5; D000077560:Enfuvirtide