OPEN Foundation

F. Blei

Iterative l-Tryptophan Methylation in Psilocybe Evolved by Subdomain Duplication

Abstract

Psilocybe mushrooms are best known for their l-tryptophan-derived psychotropic alkaloid psilocybin. Dimethylation of norbaeocystin, the precursor of psilocybin, by the enzyme PsiM is a critical step during the biosynthesis of psilocybin. However, the “magic” mushroom Psilocybe serbica also mono- and dimethylates l-tryptophan, which is incompatible with the specificity of PsiM. Here, a second methyltransferase, TrpM, was identified and functionally characterized. Mono- and dimethylation activity on l-tryptophan was reconstituted in vitro, whereas tryptamine was rejected as a substrate. Therefore, we describe a second l-tryptophan-dependent pathway in Psilocybe that is not part of the biosynthesis of psilocybin. TrpM is unrelated to PsiM but originates from a retained ancient duplication event of a portion of the egtDB gene that encodes an ergothioneine biosynthesis enzyme. During mushroom evolution, this duplicated gene was widely lost but re-evolved sporadically and independently in various genera. We propose a new secondary metabolism evolvability mechanism, in which weakly selected genes are retained through preservation in a widely distributed, conserved pathway.

Blei, F., Fricke, J., Wick, J., Slot, J. C., & Hoffmeister, D. (2018). Iterative l‐Tryptophan Methylation in Psilocybe Evolved by Subdomain Duplication. ChemBioChem19(20), 2160-2166., 10.1002/cbic.201800336.
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Production Options for Psilocybin: Making of the Magic

Abstract

The fungal genus Psilocybe and other genera comprise numerous mushroom species that biosynthesize psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine). It represents the prodrug to its dephosphorylated psychotropic analogue, psilocin. The colloquial term “magic mushrooms” for these fungi alludes to their hallucinogenic effects and to their use as recreational drugs. However, clinical trials have recognized psilocybin as a valuable candidate to be developed into a medication against depression and anxiety. We here highlight its recently elucidated biosynthesis, the concurrently developed concept of enzymatic in vitro and heterologous in vivo production, along with previous synthetic routes. The prospect of psilocybin as a promising therapeutic may entail an increased demand, which can be met by biotechnological production. Therefore, we also briefly touch on psilocybin’s therapeutic relevance and pharmacology.

Fricke, J., Lenz, C., Wick, J., Blei, F., & Hoffmeister, D. (2018). Production Options for Psilocybin: Making of the Magic. Chemistry–A European Journal., 10.1002/chem.201802758

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Biocatalytic production of psilocybin and derivatives in tryptophan synthase-enhanced reactions

Abstract

Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is the main alkaloid of the fungal genus Psilocybe, the so-called “magic mushrooms.” The pharmaceutical interest in this psychotropic natural product as a future medication to treat depression and anxiety is strongly re-emerging. Here, we present an enhanced enzymatic route of psilocybin production by adding TrpB, the tryptophan synthase of the mushroom Psilocybe cubensis, to the reaction. We capitalized on its substrate flexibility and show psilocybin formation from 4-hydroxyindole and l-serine, which are less cost-intensive substrates, compared to the previous method. Furthermore, we show enzymatic production of 7-phosphoryloxytryptamine (isonorbaeocystin), a non-natural congener of the Psilocybe alkaloid norbaeocystin (4-phosphoryloxytryptamine), and of serotonin (5-hydroxytryptamine) by means of the same in vitro approach.

Blei, F., Baldeweg, F., Fricke, J., & Hoffmeister, D. (2018). Biocatalytic Production of Psilocybin and Derivatives in Tryptophan Synthase‐Enhanced Reactions. Chemistry–A European Journal24(40), 10028-10031., 10.1002/chem.201801047.
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30 April - Q&A with Rick Strassman

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