The inhibition of phosphorylase kinase by a number of protein kinase inhibitors was examined. Both K252a and staurosporine are potent inhibitors of phosphorylase kinase with IC50values of 1.7 nM and 0.5 nM respectively. K252a shows a 300-fold selectivity for this enzyme over protein kinase C whereas staurosporine shows only a 20-fold selectivity for phosphorylase kinase. In contrast, the Roche bis-indolyl maleimides inhibit phosphorylase kinase with IC50values of approximately 1 μM and are highly selective for protein kinase C. © 1990.
Elliott, L. H., Wilkinson, S. E., Sedgwick, A. D., Hill, C. H., Lawton, G., Davis, P. D., & Nixon, J. S. (1990). K252a is a potent and selective inhibitor of phosphorylase kinase. Biochemical and Biophysical Research Communications, 171(1), 148–154. https://doi.org/10.1016/0006-291X(90)91369-4