Search results for "HIV Envelope Protein gp41"
showing 5 items of 5 documents
Hexapeptides that interfere with HIV-1 fusion peptide activity in liposomes block GP41-mediated membrane fusion
2006
AbstractUpon receptor-mediated activation, the gp41 hydrophobic, conserved fusion peptide inserts into the target membrane and promotes the kind of perturbations required for the progression of the HIV-cell fusion reaction. Using a synthetic combinatorial library we have identified all d-amino acid hexapeptide sequences that inhibited the fusion peptide capacity of perturbing model membranes. Two hexapeptides that effectively inhibited the fusion peptide in these systems were subsequently shown to inhibit cell–cell fusion promoted by gp41 expressed at cell surfaces. These observations might be of importance for understanding the mechanisms underlying fusion peptide activity and suggest new …
Free and antibody-complexed antigen and antibody profile in apparently healthy HIV seropositive individuals and in AIDS patients.
1990
The pattern of free and antibody-complexed HIV antigen and the antibody profile were investigated retrospectively in 305 serum samples taken from 22 AIDS patients before and during the development of AIDS and from 40 apparently healthy seropositive individuals. Most AIDS patients were found positive for both free and complexed antigen and had high gp41 antibody titres but low or undetectable p24 antibody. Four different patterns of HIV antigenaemia were observed: 1) positive for both free and complexed antigen; 2) negative for free HIV antigen at first, but always positive for complexed antigen; 3) positive for free antigen without complexed antigen; and 4) negative for both free and comple…
Membrane topology of gp41 and amyloid precursor protein: Interfering transmembrane interactions as potential targets for HIV and Alzheimer treatment
2009
AbstractThe amyloid precursor protein (APP), that plays a critical role in the development of senile plaques in Alzheimer disease (AD), and the gp41 envelope protein of the human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome (AIDS), are single-spanning type-1 transmembrane (TM) glycoproteins with the ability to form homo-oligomers. In this review we describe similarities, both in structural terms and sequence determinants of their TM and juxtamembrane regions. The TM domains are essential not only for anchoring the proteins in membranes but also have functional roles. Both TM segments contain GxxxG motifs that drive TM associations within the li…
Demonstration of antibodies to the surface (anti-p41) and core proteins (anti-p24) of the human immunodeficiency virus (HIV) in individuals positive …
1987
Diagnosis of infection with the human immunodeficiency virus (HIV) relies on the demonstration of antibody to this virus. Occasionally, the combined analysis of sera using ELISA and western blot reveals false-positive results. We have compared a newly developed test to detect antibodies to the core (anti-p24) and surface (anti-p41) proteins of HIV with the established tests described above. Anti-p24 and anti-p41 were negative in three individuals positive for anti-HIV by ELISA and immunoblot; they had a low risk to acquire HIV infection and were clinically and immunologically normal and suspected false positive previously. In 62 individuals at risk, anti-p41 was always positive while anti-p…
Trimeric HIV Env provides epitope occlusion mediated by hypervariable loops
2014
AbstractHypervariable loops of HIV-1 Env protein gp120 are speculated to play roles in the conformational transition of Env to the receptor binding-induced metastable state. Structural analysis of full-length Env-based immunogens, containing the entire V2 loop, displayed tighter association between gp120 subunits, resulting in a smaller trimeric diameter than constructs lacking V2. A prominent basal quaternary location of V2 and V3′ that challenges previous reports would facilitate gp41-independent gp120-gp120 interactions and suggests a quaternary mechanism of epitope occlusion facilitated by hypervariable loops. Deletion of V2 resulted in dramatic exposure of basal, membrane-proximal gp41…