Protein Kinase Inhibitors

Protein Kinases are enzymes which catalyze the addition of a phosphate (PO43-) group to a substrate protein. This reaction is called phosphorylation. Phosphorylation is the most widely prevalent bio-chemical modification (up to 30% of all human proteins can be regulated via phosphorylation) that can change the activity of a protein or regulate an enzyme by turning it on or off. The human genome contains ~ 500 protein kinase genes constituting a whopping 2% of the total number of human genes. Protein Kinases thus form a very critical component of cellular signal transduction networks controlling nearly every aspect of cellular function from cell division to apoptosis. Due to their central regulatory role in a vast array of biological processes, their activity is highly regulated. Kinases are turned on or off by phosphorylation (sometimes by the kinase itself - cis-phosphorylation also known as autophosphorylation), by binding of activator or inhibitor proteins, or small molecules, or by controlling their location in the cell relative to their substrates.

Protein kinases are often categorized based on the amino acid residues they phosphorylate: Serine/Threonine kinases (e.g. MAP Kinsases), Tyrosine Kinases (the Insulin Receptor), Histidine Kinases (common in Prokaryotes).

 Protein kinases are one of the most important categories of targets in oncology and drug discovery in today's research because of their pivotal roles in regulating cellular growth and survival. Misregulated kinase activity can often be the root cause of a disease for example, cancer, where kinases regulate many aspects that control cell proliferation, migration and death. Drugs that inhibit specific kinases are being developed and some are currently in clinical use, including Gleevec (Imatinib) and Iressa (Gefitinib). In fact 14 small molecule Protein kinase Inhibitors ("nibs") have been approved by the FDA for treatment of various types of cancers and many other candidates are in various stages of clinical trials. BioVision offers ~700 Protein Kinase Inhibitors as part of its product portfolio. BioVision also manufactures and markets sets of protein kinase inhibitors specific for a certain cellular pathway.