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University of Delaware

Biosynthesis of Para-nitro-L-phenylalanine

Technology #ud20-14

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This new technology is part of an initiative to produce chemicals via biological pathways. This is the first time that the non-standard amino acid (nsAA) para-nitro-L-phenylalanine (pNF) was produced via metabolic, and not chemical, synthesis. This amino acid has previously been incorporated into various proteins using ribosomal methods. As a protein residue, pNF is used as a probe of protein structure via tryptophan quenching or infrared sensing, an enzymatic enhancer, and an immune response stimulator among other usages. The commercial applications of pNF biosynthesis are far-reaching, including: increased enzymatic activity, therapeutic protein production, protein structural study and engineering, enhanced pNF-functionalized protein yield. 


The amino acid pNF is an nsAA used to functionalize proteins for structural studies or enhanced activity. pNF has never previously been biologically synthesized from renewable carbon feedstock. Biosynthesis of pNF could present a more affordable, milder, sustainably sourced, and enantiomerically pure alternative to chemical synthesis. Metabolic synthesis of pNF could enable one-pot synthesis and incorporation of pNF into proteins, eliminating the need to supplement cultures with externally synthesized nsAA. This metabolic pathway could make applications of pNF as a protein structural probe, enzymatic enhancer, and immune response stimulator more affordable and accessible. pNF synthesis could also act as gateway to additional nsAA synthesis through modification of the nitro group. 


· More affordable synthesis

· First biological de novo synthesis of para-nitro-L-phenylalanine

· Sourced from renewable feedstock

· Higher enantiomeric purity


This technology implemented an N-oxygenase enzyme capable of converting amino-phenyl groups to nitro-phenyl groups. By expression of the corresponding gene in engineered E. coli strains with sugar feedstock, detectable concentrations of pNF were produced.


The technology is patent pending. Further information on licensing opportunities is available on request.