Bacterial production of psilocybin and 13 related compounds was achieved by adding the enzyme PsiH to the existing biosynthesis pathway. Testing 49 different indole derivatives revealed that the pathway enzymes accept many substrates, enabling the creation of a library of new drug candidates for mental health treatment.
N-methylated tryptamines like psilocybin and DMT show promise as treatments for mental health disorders, driving interest in biosynthetic production. This work characterized two enzymes from tryptamine biosynthesis: TrpM, a tryptophan N-methyltransferase from Psilocybe serbica, and PsiD, a decarboxylase from the psilocybin pathway. TrpM was able to N-methylate 4-hydroxytryptophan, a non-native amino acid. However, incorporating TrpM into a functional psilocybin pathway was blocked because PsiD could not use N,N-dimethyl-4-hydroxytryptophan as a substrate under the tested conditions, despite acting on N-methylated and 4-hydroxylated tryptophan derivatives separately. These findings expand the known substrates for TrpM and PsiD, increasing the diversity of tryptamine biosynthetic products.