A novel cell-penetrating carrier similar to cholera toxin chimeric protein was purified and characterized.

The protein complex was successfully obtained using an in vitro recombination method.

It bound more strongly to monosialoganglioside (GM1) than (CTB)5 at low concentrations.

The transmembrane function of TAT in this protein complex was also maintained.

The expression vector provides a feasible expression frame for constructing several new macromolecular protein drugs.