Prospects for Applying Synthetic Biology to Toxicology: Future Opportunities and Current Limitations for the Repurposing of Cytochrome P450 Systems

Abstract

The 30 years since the inception of Chemical Research in Toxicology, game-changing advances in chemical and molecular biology, the fundamental disciplines underpinning molecular toxicology, have been made. While these have led to important advances in the study of mechanisms by which chemicals damage cells and systems, there has been less focus on applying these advances to prediction, detection, and mitigation of toxicity. Over the last ∼15 years, synthetic biology, the repurposing of biological "parts" in systems engineered for useful ends, has been explored in other areas of the biomedical and life sciences, for such applications as detecting metabolites, drug discovery and delivery, investigating disease mechanisms, improving medical treatment, and producing useful chemicals. These examples provide models for the application of synthetic biology to toxicology, which, for the most part, has not yet benefited from such approaches. In this perspective, we review the synthetic biology approaches that have been applied to date and speculate on possible short to medium term and "blue sky" aspirations for synthetic biology, particularly in clinical and environmental toxicology. Finally, we point out key hurdles that must be overcome for the full potential of synthetic biology to be realized.

Two‐step Screening for Identification of Drug‐metabolizing Bacterial Cytochromes P450 with Diversified Selectivity

“…Generally, human drug‐metabolizing P450s possess an extraordinary broad substrate spectrum and form distinct oxidation products, which are difficult to access via chemical synthesis . However, application of membrane bound human P450s is somewhat limited by their low expression titers, activity and process stability . For this reason, bacterial P450s with high activity and stability, easily expressible in recombinant hosts, have been subjected to rational protein design and/or directed evolution to achieve production of drug metabolites.…”

“…[5] However, application of membrane bound human P450s is somewhat limited by their low expression titers, activity and process stability. [6] For this reason, bacterial P450s with high activity and stability, easily expressible in recombinant hosts, have been subjected to rational protein design and/or directed evolution to achieve production of drug metabolites. As a result, engineered variants of the well-studied P450 BM3 from Bacillus megaterium (CYP102A1) were constructed which are not only able to oxidize various drugs but also form human drug metabolites.…”

A Stable Artificial Multienzymatic Complex Using a Heterotrimeric Protein From Metallosphaera sedula

“…Cytochrome P450 monooxygenases (P450s) are attractive biocatalysts for synthetic chemistry . The P450 superfamily catalyzes a wide variety of regio‐ and stereo‐selective oxidations, including hydroxylation, epoxidation, dealkylation, and dehalogenation of aliphatic and aromatic compounds under atmospheric conditions .…”

“…Cytochrome P450 monooxygenases (P450s) are attractive biocatalysts for synthetic chemistry. [1][2][3] The P450 superfamily catalyzes a wide variety of regio-and stereo-selective oxidations, including hydroxylation, epoxidation, dealkylation, and dehalogenation of aliphatic and aromatic compounds under atmospheric conditions. [4,5] Moreover, P450s catalyzing unusual reactions such as decarboxylation, carbene transfer, and amination have been discovered recently or designed by protein engineering.…”

Engineering of versatile redox partner fusions that support monooxygenase activity of functionally diverse cytochrome P450s

“…Illustrative of their diverse biological functions, P450s are capable of converting amongst others fatty acids, steroids, prostaglandins, terpenes, and xenobiotics such as drugs and antibiotics 4 , 5 . It is therefore not surprising that these multipurpose biocatalysts have become attractive targets for application in biotechnology and synthetic biology 6 .…”