Multiple protein kinases from Trypanosoma gambiense.

Three protein kinases were distinguished in Trypanosoma gambiense extract. The enzymes preferred phosvitin, histone, and protamine as acceptor proteins, respectively. The amino acid residues of the acceptor proteins which were phosphorylated by these protein-kinase activities were serine and- to less extent- threonine. The protein kinase activities were neither affected by cyclic nucleotides nor by cyclic AMP receptors. The molecular weights of these protein kinases were determined to be greater than 200,000, 95000 and 37000, respectively. The activities of all three protein kinases were affected to varying degrees by nucleotides and nucleosides.