Phosphorylation is a key step in post translational modification (ptm) of proteins as well as lipids and is one of the most efficient ways to regulate protein and lipid function in cells. Protein Kinases are one of the largest classes of enzymes (there are 516 family members and they constitute ~2% of all human genes) that catalyse the transfer of the γ-phosphate from ATP to acceptor hydroxyl groups on amino acids (such as serine, threonine and tyrosine) in proteins or glycosyl moieties in lipids.
Protein kinases are not only present in humans but are also found in bacteria and plants. Up to 30% of all human proteins may be subject to protein phosphorylation by protein kinase activity. Phosphorylation usually results in a functional change of the substrate or target protein such as a change in its enzyme activity, cellular localization, or association with other proteins.
Protein kinases are highly regulated proteins that participate in diverse signalling pathways in cells. Growth factors, cytokines and hormones can turn on or off the activity of various protein kinases targets which in turn regulate the function of downstream substrate proteins.
Defective signalling by protein kinases accounts for more than 400 human diseases and these targets are being actively pursued for therapeutic intervention. Targeting protein kinases by small molecule inhibitors or neutralizing antibodies has been extremely beneficial in the treatment of various human diseases such as cancer and more than 10 drugs targeting protein kinases have been approved while another 60 candidates are in clinical trials.
SignalChem offers a diverse and comprehensive range of serine/threonine kinases, receptor tyrosine kinases, cytoplasmic tyrosine kinases and lipid kinases for drug discovery efforts and functional studies.