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Real-time monitoring of tyrosine hydroxylase activity using a plate reader assay
Journal article   Peer reviewed

Real-time monitoring of tyrosine hydroxylase activity using a plate reader assay

Lydia M Vermeer, Colin A Higgins, David L Roman and Jonathan A Doorn
Analytical biochemistry, Vol.432(1), pp.11-15
01/01/2013
DOI: 10.1016/j.ab.2012.09.005
PMCID: PMC3579528
PMID: 23010244
url
https://www.ncbi.nlm.nih.gov/pmc/articles/3579528View
Open Access

Abstract

Tyrosine hydroxylase (TH) is the rate-limiting step in dopamine (DA) synthesis, oxidizing tyrosine to l-DOPA, which is further metabolized to DA. Current assays for monitoring activity of this enzyme require extensive work-up, require long analysis time, and measure end points, thereby lacking real-time kinetics. This work presents the development of the first real-time colorimetric assay for determining the activity of TH using a plate reader. The production of l-DOPA is followed using sodium periodate to oxidize l-DOPA to the chromophore dopachrome, which can be monitored at 475nm. Advantages to this method include decreased sample analysis time, shorter assay work-up, and the ability to run a large number of samples at one time. Furthermore, the assay was adapted for high-throughput screening and demonstrated an excellent Z-factor (>0.8), indicating suitability of this assay for high-throughput analysis. Overall, this novel assay reduces analysis time, increases sample number, and allows for the study of activity using real-time kinetics.
High-throughput screening Tyrosine hydroxylase Dopachrome Real-time assay Plate reader

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