Question

Many proteins are secreted in their inactive form. This is also true of many toxic proteins produced by microorganisms.Explain how the mechanism is useful for the organism producing the toxin?

Answer 1

Protoxin
A toxin produced in the inactive form is called protoxin. It gets activated at a certain pH, temperature or specific environmental conditions.



Advantages of producing inactive toxin for the host:

• A toxin produced as protoxin will remain inactive in the host organism.
• Being inactive, a toxin will not kill the host producing it. In this way, toxin is advantageous to the organism as it is not harming itself but other organisms.

Example: The Bacillus thuringiensis secretes a toxin against insects called delta endotoxin. This toxin is secreted in the form of inactive protoxin.Therefore the microorganism is protected from the harmful effects of thetoxin. They are converted into active toxins under the alkaline pH in the insect gut.