Terpene synthases screening in agarwood tree <i>Aquilaria yunnanensis</i> leads to the discovery of agarospirol.
This study identifies AyTPS1 as the enzyme responsible for producing agarospirol, which is significant for the industrial production of this valuable compound.
Where it sits
this study against the rest of the epitalon (epithalon) corpusSummary and findings
This study screened terpene synthase genes from the agarwood tree Aquilaria yunnanensis to identify those involved in the biosynthesis of agarospirol. A total of 26 TPS genes were characterized, leading to the identification of AyTPS1 as the enzyme responsible for producing agarospirol. The structure of agarospirol was confirmed using NMR spectroscopy.
Abstract
Agarwood, renowned as one of the most valuable natural materials in the world of fragrance, is notoriously difficult and time-consuming to obtain, creating a critical bottleneck for its utilization and conservation. Sesquiterpenes are the key constituents of agarwood, with agarospirol recognized as one of its characteristic compounds. Nevertheless, the biosynthesis of agarospirol remains unreported. Here, we conducted a functional screening of terpene synthase (TPS) genes from the agarwood-producing tree <i>Aquilaria yunnanensis.</i> Using a heterologous expression system in <i>Saccharomyces cerevisiae</i>, we characterized 26 TPS genes, identifying 30 structurally diverse sesquiterpene products. Among them, AyTPS1 was identified as an agarospirol-producing sesquiterpene synthase, and the structure of the enzymatically produced agarospirol was unequivocally confirmed by NMR spectroscopy. Furthermore, model-guided mutagenesis of AyTPS1 revealed that residues L283 and G435 markedly influence the distribution of agarospirol and related eudesmane-type sesquiterpenes, suggesting their involvement in shaping the active-site environment for spiro-ring formation and hydroxylated product formation. The elucidation of the AyTPS1 and its catalytic mechanism lays a crucial foundation for the industrial-scale biotechnological production of this valuable sesquiterpene.
Background
The study addresses the challenge of agarwood production, which is valuable in fragrance but difficult to obtain. Sesquiterpenes are key components of agarwood, with agarospirol being a significant compound. Understanding the biosynthesis of agarospirol is essential for its conservation and potential industrial use.
Methods
The study utilized a functional screening approach to analyze terpene synthase genes from Aquilaria yunnanensis. A heterologous expression system in Saccharomyces cerevisiae was employed to characterize the genes. The primary outcome was the identification of sesquiterpene products, specifically focusing on agarospirol production.
Results
The functional screening led to the identification of 30 sesquiterpene products, with AyTPS1 being recognized as the synthase for agarospirol. The study confirmed the structure of agarospirol through NMR spectroscopy. Specific residues in AyTPS1 were found to influence product distribution.
Interpretation
This research adds to the understanding of sesquiterpene biosynthesis, particularly for agarospirol. While the findings are statistically significant in identifying the enzyme, the clinical relevance is limited as the study does not involve human subjects or clinical outcomes. Confounding factors include the use of a heterologous expression system and the lack of in vivo data.
Key findings
- Identified 30 structurally diverse sesquiterpene products from 26 TPS genes.
- AyTPS1 was confirmed as an agarospirol-producing sesquiterpene synthase.
- Residues L283 and G435 of AyTPS1 influence the distribution of agarospirol and related compounds.
Limitations
- Not conducted in human subjects.
- Utilized a heterologous expression system.
- No clinical outcomes reported.
- Focus on enzymatic characterization rather than practical applications.