In vitro enzyme assays provide sensitive and quantitative approaches to studying activity, identifying substrates or performing inhibitor analysis. These approaches can help to study enzymes that regulate different cellular processes in an organism. In addition, enzyme assays can be used to screen protein inhibitors to identify novel drug candidates. In eukaryotes, phosphatidylinositol kinase and phosphatase are enzymes that regulate the level of phosphorylated phosphatidylinositol, which...
