Kinases/Enzyme Drug Discovery In Vitro Assays

Background of Kinase/Enzyme

Kinases are capable of selective modulation of particular proteins, lipids, carbohydrates, and other molecules through phosphorylation, which play roles in signal transduction and the alterations of activity, cellular location, and interaction among molecules. Enzymes are proteins responsible for the catalyzation of substrates converting into products. Except for the protein kinase C activator, ingenol mebutate, inhibitors of enzymes and kinases have been developed as treatments for multiple diseases.

Fig.1 Mutations in the classical MAP kinase cascade cause cancer. (Cohen, 2021)

Distributions and Functions of Kinase/Enzyme

Kinases and enzymes are widely expressed. Kinases are involved in multiple cellular signal transduction, participating in physiological and pathological processes, including metabolism, protein regulation, cellular transport, secretion, inflammation, cell differentiation, proliferation, survival, apoptosis, etc. Kinases regulate molecular ability through phosphorylation, which makes kinases become drug targets for diseases, such as brain cancer, breast cancer, lung cancer, insulin resistance, leukemia, and agammaglobulinaemia. Enzymes participate in a vast array of biological activities, including metabolism, regulation of the ability of molecules, post-translational modification, etc. Dysfunction of enzymes can lead to diseases, including Tay–Sachs disease, lactose intolerance, skin cancer, high cholesterol, etc.

Subtypes and Mechanisms of Kinase/Enzyme

Protein kinases are classified into protein kinase C (PKC), cyclin-dependent kinases (CDKs), and mitogen-activated protein kinases (MAPKs). They phosphorylate the hydroxyl groups of serine and/or threonine with co-substrate ATPs. Lipid kinases are divided into phosphatidylinositol kinases (PIPKs) and sphingosine kinases (SKs). There are also carbohydrate kinases involved in glycolysis, including hexokinases and phosphofructokinases. Enzymes are classified into oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. Enzyme reaction rates can be reduced by numerous inhibitors of enzymes. Competitive inhibitors compete with physiological substrates for binding sites, while non-competitive inhibitors irreversibly bind to other parts of the enzyme. Inhibitors also suppress enzyme activity by affecting enzyme synthesis.

Published Data

References

1. Cohen, P.; et al. Kinase drug discovery 20 years after imatinib: Progress and future directions. Nature reviews drug discovery. 2021, 20(7): 551-569.
2. Beg, A.; et al. High throughput screening, docking, and molecular dynamics studies to identify potential inhibitors of human calcium/calmodulin-dependent protein kinase IV. Journal of Biomolecular Structure and Dynamics. 2019, 37(8), 2179-2192.