High-throughput assay of tyrosine phenol-lyase activity using a cascade of enzymatic reactions.

Tyrosine phenol-lyase (TPL) exhibits great potential in industrial biosynthesis of l-tyrosine and its derivates. To uncover and screen TPLs with excellent catalytic properties, there is unmet demand for development of facile and reliable screening system for TPL. Here we presented a novel assay format for the detection of TPL activity based on catechol 2,3-dioxygenase (C23O)-catalyzed reaction.

Recent advancements in enzyme engineering via site-specific incorporation of unnatural amino acids.

With increased attention to excellent biocatalysts, evolving methods based on nature or unnatural amino acid (UAAs) mutagenesis have become an important part of enzyme engineering. The emergence of powerful method through expanding the genetic code allows to incorporate UAAs with unique chemical functionalities into proteins, endowing proteins with more structural and functional features. To date, over 200 diverse UAAs have been incorporated site-specifically into proteins via this methodology and many of them have been widely exploited in the field of enzyme engineering, making this genetic code expansion approach possible to be a promising tool for modulating the properties of enzymes.

Purification and Biochemical Characterization of a Tyrosine Phenol-lyase from Morganella morganii.

Tyrosine phenol-lyase (TPL) is a valuable and cost-effective biocatalyst for the biosynthesis of L-tyrosine and its derivatives, which are valuable intermediates in the pharmaceutical industry. A TPL from Morganella morganii (Mm-TPL) was overexpressed in Escherichia coli and characterized. Mm-TPL was determined as a homotetramer with molecular weight of 52 kDa per subunit.