Interactions

     Coprinopsis atramentaria is detritivorous, meaning it lives off of dead organic material.  This provides great ecological benefits, like reducing the amount of decaying organic material, and recycling the nutrients trapped in dead debris, eventually reintroducing the nutrients back to the food-web.

     Edible: Being saprobic (detritivorous), means it is not parasitic and does not form any mutualistic or commensal symbiotic relationships with other organisms.  However, they do interact with other organisms, for example they compete with other fungi and plants for the nutrients and water in the soil.  They also commonly serve as a habitat for many organisms like bacteria and protists.  Many mushrooms even serve as a food source for other organisms like insects, bacteria, smaller mammals, like pigs, squirrels, chipmunks, and last but not least, humans.  They are actually very nutritious and contain copper, iron, vitamin c, and more potassium per gram than bananas! They are also a low calorie/low cholesterol food that contains a significant amount of fiber.

 Toxicity:  But there is a catch, Coprinopsis atramentaria is known for being poisonous when consumed with alcohol!  This mushroom isn’t a directly toxic organism, it actually metabolizes the chemical coprine (illustrated to the left) into a chemical that interferes with the breakdown of ethanol, causes a build up of aldehydes in your bloodstream, thus making the alcohol poisonous.  The effects of this are similar to that of the drug disulfiram (antabuse).  This drug is used to treat people with an alcohol dependence because it causes symptoms like severe nausea, vomiting, and headaches upon alcohol consumption.  Similar to this drug, after drinking alcohol before, with, or after the mushroom Coprinosis atramentaria, the onset of symptoms will occur anytime from 5 minutes, to two hours after consumption, and last anywhere from 45 minutes to a couple of hours.  These symptoms include an elevated heart rate, flushing of the skin on the upper half of the body, headache, rapid breathing, weakness, dizziness, nausea and vomiting.  Keep in mind that the coprine can keep your body susceptible to this poisonous interaction for up to a few days, and in rare cases, up to a week. 

     The True Culprit:  The novelty of the chemical coprine, is in the fact that it is the first example of an enzyme inhibitor that contains a cyclopropyl ring at the oxidation state of cycloproanone.  So first off, the side effects of this sensitivity to alcohol are actually caused by the inhibition of aldehyde dehydrogenase, which a vital enzyme responsible for the metabolism of ethanol.  In essence, coprine isn’t toxic, however it does modify and amplify alcohol’s toxicity.  Coprine produces a metabolic product of cyclopropanone hemiaminal, that ultimately becomes the true culprit, cyclopropanone hydrate (illustrated to the right).  This acts as a substrate analogue and is indeed ultimately the chemical responsible for the inhibition of aldehyde dehydrogenase.  This is the interaction that causes aldehyde poisoning.

     Coprine for Dummies:  So essentially, the break down of coprine in your body results in a chemical that is similar in structure to a different chemical that is vital in the breakdown of ethanol,  which ultimately distracts the enzymes that break down alcohol by causing a diversion.  This leads to aldehyde poisoning (build up of alhedydes in your blood).

     The Dirty Details:  Here are some dirty details of the chemical interactions.  An enzyme catalyzes the dehydration of cyclopropanone hydrate into cycloproanone.  Cycloproanone binds to the active-site thiol on the enzyme aldehyde dehydrogenase, and creates a kinetically stable thiohemiketal.   Thiohemiketals are analogous (similar to) thiohemiacetals, which are obligatory intermediates in the enzyme-catalyzed oxidation of aldehydes.  Thus Cyclopropanone hydrate ultimately lessens the amount of enzymes available to act on thio reagents, which causes a build up of aldehyde levels in the blood and impedes the metabolism of ethanol.  This is what causes the "poisionous" reaction that results in aldehyde poisoning.

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