font size

Definition of Toxin, anthrax

Toxin, anthrax: The toxic substance secreted by the bacterium Bacillus anthracis, the causative agent of the disease anthrax.

Anthrax toxin is made up of three proteins. One is protective antigen and two are enzymes that are called edema factor and lethal factor. The protective antigen binds to surface receptors on the host's cell membranes. After being cleaved by a protease, protective antigen binds to the two toxic enzymes -- edema factor and lethal factor -- and mediates their transportation into the cytosol (the soluble portion of the cytoplasm) where they exert their pathogenic (disease-causing) effects. Lethal factor is the crucial pathogenic enzyme. It is the killer in the toxin.

Anthrax toxin is not yet fully fathomed. The receptor for protective antigen, named anthrax toxin receptor, has been discovered to be a type I membrane protein with an extracellular Von Willebrand factor A domain that binds directly to protective antigen. And lethal factor has been found to cleave members of what is called the MAPKK (mitogen-activated protein kinase kinase) family and to disrupt cellular signalling.

Source: MedTerms™ Medical Dictionary
http://www.medicinenet.com/script/main/art.asp?articlekey=18852
Last Editorial Review: 6/14/2012

Drug Medical Dictionary of Terms by Letter

Top RxList Drug News

Allergies & Asthma

Improve treatments & prevent attacks.

advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations