two cyclic amp-independent casein kinases can be isolated from human erythrocyte hemolysate , one of which ( referred to as 'casein kinase s ' ) phosphorylates only serine residues of whole commercial casein , while the other ( referred to as 'casein kinase ts ' ) phosphorylates both serine and threonine residues of the same substrate .
C0054846
casein kinase
C0108555
casein kinase ts