[Neutralising properties for HIV virus of hybrid protein MalE-CD4 expressed in E. coli and purified in 1 step].

Genetic fusions allowing the expression in E. coli of hybrid proteins between a bacterial periplasmic maltose binding protein (MalE) and the CD4 molecule (the receptor of the HIV virus) have been constructed. One of them has kept most of the properties of each constituent: it is exported, can be purified in one step on an affinity column, interacts with anti-MalE and anti-CD4 antibodies, binds HIV gp 120 protein and inactivates HIV virus in an in vitro test.