Immunological properties and peptide mapping of two type I casein kinases from yeast

Two protein kinases of Mr 43,000 and 23,000 from yeast, belonging to type-1 casein kinases, were purified to apparent homogeneity and used for investigation of their immunological affinity and for comparison of their peptide map patterns. The results obtained showed that antibodies against the 43 kDa kinase did not react with the 23 kDa enzyme. Moreover, the peptide maps of the radioiodinated kinases obtained either by chemical cleavage of peptide bonds in the presence of CNBr or by a limited digestion with V8 protease were completely different. All these observations point to the lack of relatedness between the two investigated enzymes.