Glucokinase is an enzyme that phosphorylates glucose to glucose-6-phosphate in the first step of glycolysis. It serves as a glucose sensor and can regulate insulin secretion by beta cells in the pancreas. Activators of glucokinase bind to an allosteric site of the enzyme and increase glucokinase activity. It has been shown that these activators can decrease blood glucose in animals with type 2 diabetes and induce glucose-stimulated insulin secretion. We developed an enzymatic assay to screen for novel activators of glucokinase that will increase its enzymatic activity. We used a kinase-glo luminescent assay that looks at ATP consumption by glucokinase. In the assay, glucokinase catalyzes glucose phosphorylation in the presence of ATP. The reaction is left to incubate and then a kinase-glo reagent, containing beetle luciferin and luciferase, is added to stop the reaction. The beetle luciferin and remaining ATP is catalyzed by luciferase, producing oxyluciferin, AMP, and light. We measure the light absorbance in order to measure the activity of glucokinase. In the assay luminescence is inversely proportional to glucokinase activity. This method can now be used to screen the Broad chemical library for potential small-molecule activators of glucokinase. Successful identification of effective small-molecule activators can lead to beta cell proliferation and new clinical treatments for diabetes.
PROJECT: Identifying Small-Molecule Activators of Glucokinase Using a Kinase-Glo Luminescent Assay
The Broad fosters a community of collaboration and passionate scientists, which is instantly contagious. Working in a lab this summer allowed me to understand the scientific process in a way I could have never learned in a classroom. The Broad pushed me to ask difficult questions and to find new ways to solve these questions in novel ways, leading science in different directions.