K-252c is a cell-permeable, reversible, and ATP-competitive inhibitor of protein kinase C (PKC) and protein kinase A (PKA) with IC50 value of 2.45 μM and 25.7 μM, respectively. This component was inhibits β-lactamase, malate dehydrogenase and chymotrypsin with IC50 values of 8, 8 and 10 μM respectively [1].

Protein kinase is known as kinase enzymes that modify other proteins by chemically adding phosphate groups to them (phosphorylation). Phosphorylation can result in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins in the cells. PKA and PKC are important family member of AGC kinases.

K-252a was previously shown to block nerve growth factor (NGF)-induced neurite outgrowth and the changes in protein phosphorylation elicited by NGF in PC12h cells [2].

The effect of K-252c was also investigated on the severe combined immunodeficient (SCID) mouse-human skin model of psoriasis. It was shown that psoriasis significantly improved after 2 weeks treatment of K-252c [3].

References:
1.? Fabre S, Prudhomme M, Rapp M. Protein kinase C inhibitors; structure-activity relationships in K252c-related compounds. Bioorg Med Chem 1993,1:193-196.
2.? Hashimoto S. K-252a, a potent protein kinase inhibitor, blocks nerve growth factor-induced neurite outgrowth and changes in the phosphorylation of proteins in PC12h cells. J Cell Biol 1988,107:1531-1539.
3.? Raychaudhuri SP, Sanyal M, Weltman H, Kundu-Raychaudhuri S. K252a, a high-affinity nerve growth factor receptor blocker, improves psoriasis: an in vivo study using the severe combined immunodeficient mouse-human skin model. J Invest Dermatol 2004,122:812-819.