Amazing stuff! Reconstructing extinct enzymes could have wide ranging applications in the future.
"... Researchers ... have experimentally demonstrated for the first time how cannabis acquired the ability to produce these cannabinoids. In the process, they also developed enzymes that show promise for the biotechnological production of cannabinoids for medicinal applications. ...
the researchers reconstructed extinct enzymes that were active millions of years ago in ancestors of the cannabis plant. In cannabis, enzymes play a key role in the production of cannabinoids—bioactive compounds with, among other things, medicinal potential. ..."
"... The researchers used a technique known as ancestral sequence reconstruction. Based on DNA from modern plants, this method makes it possible to infer what enzymes looked like millions of years ago. These ‘ancestral enzymes’ were then resurrected in the laboratory and experimentally tested. The study provides the first experimental evidence that the biosynthesis of cannabinoids such as THC originated within a relatively recent ancestor of cannabis and subsequently became increasingly refined. ..."
From the abstract:
"Cannabinoids, such as tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA), are bioactive and medicinally relevant compounds found in the cannabis plant (Cannabis sativa L.).
These three compounds are synthesised from a single precursor, cannabigerolic acid (CBGA), through regioselective reactions catalysed by different cannabinoid oxidocyclase enzymes. Despite the importance of cannabinoid oxidocyclases for determining cannabis chemotype and properties, the functional evolution and molecular mechanism of this enzyme family remain poorly understood.
To address this gap, we combined ancestral sequence reconstruction and heterologous expression to resurrect and functionally characterise three ancestral cannabinoid oxidocyclases.
Results showed that the ability to metabolise CBGA originated in a recent ancestor of cannabis and that early cannabinoid oxidocyclases were promiscuous enzymes producing all three THCA, CBDA and CBCA.
Gene duplication and diversification later facilitated enzyme sub functionalisation, leading to extant, highly-specialised THCA and CBDA synthases.
Through rational engineering of these ancestors, we designed hybrid enzymes which allowed identifying key amino acid mutations underlying the functional evolution of cannabinoid oxidocyclases.
Ancestral and hybrid enzymes also displayed unique activities and proved to be easier to produce heterologously than their extant counterparts.
Overall, this study contributes to understanding the origin, evolution and molecular mechanism of cannabinoid oxidocyclases, which opens new perspectives for breeding, biotechnological and medicinal applications."
Origins of THC, CBD and CBC in cannabis revealed
Origins of THC, CBD and CBC in cannabis revealed (original news release) "Where do the well-known cannabis compounds THC, CBD and CBC come from? Researchers ... have experimentally demonstrated for the first time how cannabis acquired the ability to produce these cannabinoids. In the process, they also developed enzymes that show promise for the biotechnological production of cannabinoids for medicinal applications."
Fig. 5 Major modifications in the substrate binding region of ancestral and hybrid cannabinoid oxidocyclases.
