Analysis of the disulfide bond arrangement of the HIV-1 envelope protein CON-S gp140 ΔCFI shows variability in the V1 and V2 regions.
Disulfide bonding of cysteines is one of the most important protein modifications, and it plays a key role in establishing/maintaining protein structures in biologically active forms. Therefore, the determination of disulfide bond arrangement is one important aspect to understanding the chemical structure of a protein and defining its functional domains. Herein, aiming to understand how the HIV-1 envelope protein's structure influences its immunogenicity, we used an MS-based approach, liquid chromatography electrospray ionization Fourier transform ion cyclotron resonance (LC/ESI-FTICR) mass spectrometry, to determine the disulfide linkages on an oligomeric form of the group M consensus HIV-1 envelope protein (Env), CON-S gp140 ΔCFI. This protein has marked improvement in its immunogenicity compared to monomeric gp120 and wild-type forms of gp140 Envs. Our results demonstrate that the disulfide connectivity in the N-terminal region of CON-S gp140 ΔCFI is different from the disulfide bonding previously reported in the monomeric form of gp120 HIV-1 Env. Additionally, heterogeneity of the disulfide bonding was detected in this region. These data suggest that the V1/V2 region does not have a single, conserved disulfide bonding pattern and that variability could impact immunogenicity of expressed Envs.
Department of Chemistry, University of Kansas, Lawrence, Kansas 66047, USA.
Eden P
EP
Go
Ying
Y
Zhang
Sushma
S
Menon
Heather
H
Desaire
D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D016384:Consensus Sequence; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D010449:Peptide Mapping; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000378:metabolism; D054299:env Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000378:metabolism
D004220:Disulfides; D010446:Peptide Fragments; D054299:env Gene Products, Human Immunodeficiency Virus; C097729:gp140 envelope protein, Human immunodeficiency virus 1; D012710:Serum Albumin, Bovine; D014357:Trypsin