UCLA researchers in the Department of Chemical and Biomolecular Engineering have developed a novel biochemical synthesis process to produce D-Tryptophan at high yield and 98% enantiomeric excess with peptide synthetase IvoA from recombinant yeast.
BACKGROUND:
D-tryptophans are important building blocks of many peptide-based pharmaceuticals. The common biocatalytic processes to synthesize D-tryptophan base on kinetic resolution by using an enantioselective enzyme and have a limited theoretical yield of 50%. The more recent dynamic kinetic resolution and stereoinversion reaction cascades improve the yield, but multiple steps are required to convert L-tryptophan to D-tryptophan. A more efficient method to produce D-tryptophan and simplify the L-D conversion will benefit the production of various pharmaceutical compounds.
INNOVATION:
UCLA researchers in the Department of Chemical and Biomolecular Engineering have developed a novel biochemical synthesis method using a single-module non-ribosomal peptide synthetase IvoA from Aspergillus nidulans to D-tryptophan. IvoA catalyzes ATP-dependent unidirectional stereoinversion of L-tryptophan to D-tryptophan. A recombinant yeast strain was modified to overexpress IvoA. The recombinant strain yielded free D-tryptophan at 10 mg/L after a 3-day culture, with a high enantiomeric excess of 98%. A library of substituted D-tryptophan analogues can be accessed by enzymatic reactions in vitro using recombinant IvoA purified from yeast.
POTENTIAL APPLICATIONS:
• Pharmaceutical production
• Dietary supplement
• Food processing
ADVANTAGES:
• High yield
• One step reaction
• High purity
DEVELOPMENT-TO-DATE:
Synthesis demonstrated on recombinant yeast and purified recombinant enzymes.