Toxin

A toxin (Greek τοξίνη, ancient Greek toxins pronounced, " the poisonous [ substance] ") is a toxin that is synthesized by a living creature. The scientific discipline that deals with the study of poisons, their effects and their treatment, the toxicology. It deals with toxic substances, animals, plants and microorganisms, with the physiological mechanisms of toxicity and their quantitative aspects. The toxic effect of a substance on a living organism is called toxicity.

In scientific English-speaking countries, the term has Toxinology, established as a branch of toxicology that deals with toxins. The German translation Toxinology is increasingly finding in the German language area.

History

Plant, fungal and animal poisons known to man for many centuries. The first bacterial toxin, diphtheria toxin, was discovered in 1888 and isolated by Émile Roux and Alexandre Yersin. Various toxins have been reported in connection with the bioterrorism to a wider public.

Chemical composition and effects

Toxins are usually peptides or proteins ( coll: protein compounds ), some are alkaloids ( especially plant toxins). They are made of organisms to their defense and disrupt or damage the basic cellular processes of other organisms. For example, some bacterial toxins block protein synthesis at the ribosomes. Many snake venoms are themselves proteases, ie those proteins that degrade other proteins.

Bacterial toxins are divided into exotoxins and endotoxins.

Exotoxins

Exotoxins are complex composite proteins. They are precipitation poisons permanently released by bacteria. You are thermolabile, which means that they are not resistant to heat and cold. Exotoxins are found on plasmids or core equivalent. You are immunogenic, but do not leave long-lasting immunity. They can be converted by heating or in Formalineinwirkung toxoids.

Endotoxins

Endotoxins are composed of lipopolysaccharides. They are found in the outer envelope of Gram-negative bacteria and are released during the decomposition of the microorganisms. Under certain circumstances, very large amounts of toxins can thereby be released. Endotoxins are also thermolabile. The lipid A is the toxic component. Antibodies react with the Polysaccharidseitenkette. It is very fast in general, which means that very quickly an antidote must be applied.