The kit provides an easy method for measuring the activity of the different casein kinases by an in vitro phosphorylation of α-casein. The kit includes CK I and CK II specific inhibitors to distinguish between CK I and CK II activities in the biological sample. The kit can be used for CK activity measurement in cell lysates, tissue homogenates, column fractions, or of the purified enzyme
Casein kinases (CK) are highly conserved serine/threonine kinases, ubiquitous in eukaryotic organisms, and defined by their substrate preference for casein. They are insensitive to cyclic nucleotides, Ca2+, and phospholipids. Casein kinases are grouped into two main families, type I and type II, according to their structure, specificity, and response to effectors.