Heparin and its derivatives bind to HIV-1 recombinant envelope glycoproteins, rather than to recombinant HIV-1 receptor, CD4.

We have employed a direct radiolabel binding assay to investigate the interaction between3H-heparin and recombinant envelope glycoproteins, rgp120s, derived from several different isolates of HIV-1. Comparable dose-dependent binding is exhibited by rgp120s from isolates IIIB, GB8, MN and SF-2. Under identical experimental conditions the binding of3H-heparin to a recombinant soluble form of the cellular receptor for gp120, CD4, is negligible.

Can microorganisms convert antimony trioxide or potassium antimonyl tartrate to methylated stibines?

No evidence could be found for the production, in culture, of methylated antimony compounds from water-insoluble or soluble antimony derivatives by the aerobes, Scopulariopsis brevicaulis or Bacillus sp. or by anaerobes associated with cot mattress materials. The study does not support the hypothesis that volatile organoantimony compounds are a cause of cot deaths.

Low anticoagulant heparin retains anti-HIV type 1 activity in vitro.

Heparin is a potent inhibitor of HIV-1 replication, in addition to being a well-established inhibitor of blood coagulation. The major anticoagulant activity of heparin results from binding to the plasma protein antithrombin (AT). The high-affinity binding site for AT is a specific pentasaccharide sequence that is of low abundance and completely absent from the majority of heparin chains.

Anti-HIV-1 activity of chemically modified heparins: correlation between binding to the V3 loop of gp120 and inhibition of cellular HIV-1 infection in vitro.

Chemically modified heparins were tested for their activities in (i) inhibiting HIV-1 replication in vitro and (ii) inhibiting the binding to recombinant HIV-1 gp120 of monoclonal antibodies specific for the V3 loop. The results reveal that N-desulfation reduces activity, although this is largely restored on N-acetylation. Selective O-desulfation also markedly reduces activity, whereas carboxyl reduction has little effect.

Heparin specifically inhibits binding of V3 loop antibodies to HIV-1 gp120, an effect potentiated by CD4 binding.

Objective: To investigate the binding of the sulphated polysaccharides, dextran sulphate and heparin, to CD4 and gp120 in order to examine the anti-HIV mechanisms of these compounds.

Design: In order to study the molecular mechanisms involved, the binding of sulphated polysaccharides to recombinant (r) sCD4 and gp120 was investigated in solid-phase binding studies that employed various monoclonal antibodies directed against known epitopes on these proteins, including the V3 loop of gp120.

Methods: The ability of sulphated polysaccharides to inhibit both the binding of gp120 to CD4 and the binding of the monoclonal antibodies was investigated by enzyme-linked immunosorbent assays.