A Homogenous Luminescence Assay Reveals Novel Inhibitors for Giardia LambliaCarbamate Kinase
Catherine Z Chen 1, Noel Southall 1, Andrey Galkin 2, Kap Lim 2, Juan J Marugan 1, Liudmila Kulakova2, Paul Shinn1, Danielle van Leer 1, Wei Zheng 1, #, Osnat Herzberg 2, 3, *, #
1 National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA
2 Institute for Bioscience and Biotechnology Research, University of Maryland 9600, Rockville MD 20850, USA
3 Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
The human pathogen Giardia lamblia is an anaerobic protozoan parasite that causes giardiasis, one of the most common diarrheal diseases worldwide. Although several drugs are available for the treatment of giardisis, resistance to these drugs has been reported and is likely to increase. The Giardia carbamate kinase (glCK) plays an essential role in Giardia metabolism and has no homologs in humans, making it an attractive candidate for anti-Giardia drug development. We have developed a luminescent enzyme coupled assay to measure the activity of glCK by quantitating the amount of ATP produced by the enzyme. This assay is homogeneous and has been miniaturized into a 1536-well plate format. A pilot screen against 4,096 known compounds using this assay yielded a signal-to-basal ratio of 11.5 fold and Z’ factor of 0.8 with a hit rate of 0.9 % of inhibitors of glCK. Therefore, this Giardia lamblia carbamate kinase assay is useful for high throughput screening of large compound collection for identification of the inhibitors for drug development.
Keywords: Carbamate kinase, Giardia, high throughput screening, assay development..
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* Address correspondence to this author at the Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, MD 20850, USA; Tel: (240) 314-6245; E-mail: email@example.com#Both authors contribute equally