Cry4Ba

Cry4Ba is a protein produced by the bacterium Bacillus thuringiensis. Bacillus thuringiensis, often abbreviated as Bt, is a gram-positive, soil-dwelling bacterium that is known for its ability to produce insecticidal proteins. These proteins are often referred to as Bt toxins. Cry4Ba is one such protein, belonging to the Cry4 family of Bt toxins.

These toxins are synthesized by the bacterium during its sporulation phase and are stored within crystalline inclusions called parasporal bodies. When an insect ingests these spores and crystals, the alkaline environment of the insect's midgut causes the crystals to dissolve. This releases the protoxin, which is then activated by proteases into a toxic form.

Cry4Ba specifically targets larvae of certain dipteran insects, such as mosquitoes and black flies. Upon activation, the Cry4Ba toxin binds to specific receptors on the insect midgut epithelial cells. This binding leads to the formation of pores in the cell membranes, causing cell lysis and ultimately leading to the death of the insect. Due to its specificity, Cry4Ba has been explored for use in biological control strategies against insect vectors of diseases. Its use is considered environmentally friendly as it exhibits low toxicity to non-target organisms, including mammals and beneficial insects. Research continues to explore the precise mechanisms of action and potential applications of Cry4Ba and other Bt toxins.