Alpha Toxin or alpha-toxin refers to several different protein toxins produced by bacteria.

Like other bacteriocins, vibriocins are protein toxins.

Tetanolysin belongs to a family of protein toxins known as cytolysins which bind to cholesterol.

The protein toxin in a type II system is inhibited post-translationally by the binding of another protein antitoxin.

Insect toxins are various protein toxins produced by insect species.

It consists of a stable protein toxin and an antitoxin that reversibly binds to and neutralizes it.

Many pathogens have Type III secretion systems which can directly inject protein toxins into the host cells.

An example is ricin, an extremely potent protein toxin found in castor oil beans.

The venom of widow spiders (Latrodectus) contains several protein toxins, called latrotoxins, which selectively target against either vertebrates, insects or crustaceans.

Cry3Bb1 is a protein toxin from Bacillus thuringiensis.