A Computational Framework for Naloxone Biosynthetic Pathway Design using Deep Learning
No Access Until
Permanent Link(s)
Collections
Other Titles
Author(s)
Abstract
Opioids are a class of drugs highly valued for their potent analgesic properties; however, they are also highly addictive and cause severe side effects, including death because of respiratory depression. The Centers for Disease Control and Prevention estimate that 130 Americans die daily from opioid overdoses and that the number of opioid overdose deaths in 2017 represents a six-fold increase compared to 1999. Alternative manufacturing methods are needed to overcome the cost and availability of naloxone, an opioid overdose antidote. Toward this need, we developed a computational pipeline to design novel biosynthetic routes from morphine to naloxone. This pipeline combined deep learning with computational biochemistry in an in-silico framework to efficiently explore the biosynthetic pathways' design space.In this study, we assembled metabolic reaction and enzymatic template data from public databases. Then we enriched the reaction dataset with artificial metabolic reactions generated by enzymatic templates. Two neural network-based pathway ranking models were trained as binary classifiers, taking potential reactant and product pairs as input and quantifying the likelihood of a 1-step/2-step enzymatic pathway. Combining these two models with enzymatic templates, we built a multistep retrobiosynthesis pipeline and validated it by computationally reproducing natural and non-natural pathways. While the initial pathway prediction results were encouraging, the framework does have its limitations. To enhance our synthetic pathways generation; improving our precursor candidate rankings' accuracy, we have developed an additional model incorporating thermodynamic constraints. This model takes potential reactant and product pairs as input and predicts the feasibility of chemical reactions within a retrosynthetic workflow, leveraging thermodynamic principles. By integrating thermodynamic considerations, we aim to refine further and enhance our pathway predictions' accuracy, which will be the groundwork for guiding the experimental synthesis of naloxone in our lab.