Protamine kinases

Protamine kinase (from rainbow trout testes) [37278-10-7] [EC 2.7.1.70]. Partial purification by hydoxylapatite chromatography followed by biospecific chromatography on nucleotide coupled Sepharose 4B (the nucleotide was 8-(6-aminohexyl)amine coupled cyclic-AMP). [Jergil et al. Biochem J139 441 1974.]... 

This enzyme [EC 2.7.1.70], also referred to as protamine kinase, catalyzes the reaction of ATP with protamine to produce ADP and an O-phosphoseryl residue in protamine. The enzyme will also phosphorylate histones and it requires cAMP. 

The newly synthesized protamine is phosphorylated by adenosine triphosphate in cytoplasm catalyzed by protamine kinase (Langan and Smith, 1967 Ingles and Dixon, 1967 Marushige etal. 1969 Jergil and Dixon, 1970). The phosphorylation occurs at the hydroxyl groups of serine residues (Trevithick et al., 1967 Ingles and Dixon, 1967). Protein kinase has been found in various mammalian tissues... 

Jergil, B., Dixon, G. H. Protamine kinase from rainbow trout testis. Partial purification and characterization. J. biol. Chem. 245, 425—434 (1970). 

Additional information <1> (<1> isozyme of calmodulin-dependent multifunctional protein kinase II in smooth-muscle [5] <1> caldesmon is not a substrate of smooth-muscle myosin light-chain kinase [3] <1> no substrates are bovine cardiac C-protein, bovine brain fodrin, rabbit skeletal muscle glycogen synthase, phosphorylase B, troponon (I -I- T -I- C), actin, tropomyosin, smooth-muscle actin, filamin, vinculin, cr-actinin, protamine or phosvitin [1]) [1-3]... 

The activity of protein kinase is readily assayed by measuring the rate of transfer of P from [y- P]ATP to a protein substrate, such as histone, casein, or protamine [77,80,82]. The phosphorylated substrate is collected on a filter, eluted, and counted. 

Polysaccharides, 44, 58 Prokaryote Cell, 7 Proline, 439 Promoters, 391 Protamines, 149 Proteans, 151 Protein Biosynthesis, 448 Protein Catabolism, 428 Protein Maturation, 449 Proteins, 262 Purine Metabolism, 379 Purines, 113 Pyridoxine, 229 Pyrimidines, 113 Pyruvate Kinase, 288... 

The human plasma metallo-protease carboxypeptidase N (CPN, arginine carboxypeptidase, anaphylatoxin inactivator, kininase I, EC 3.4.17.3) catalyzes the release of the basic amino acids lysine and arginine from the C-termini of peptides and proteins such as bradykinin and kallidin [95], the anaphylatoxins C3a, C4a, and C5a [96,97], fibrinopeptides 6A and 6D [98], hexapeptide enkephalins [99], protamine [100], and the creatine kinase MM-isoenzyme [101,102]. Its most likely physiological function is to protect the organism from the actions of potent peptides, which may escape from tissues or be released in the circulation. 

Cyclic AMP-independent protein kinases are found in numerous animal tissues. Some are specific for basic proteins such as the histones and protamines. Others are specific for acidic proteins such as phosvitin and casein, while others may show both types of activity. Enzymes that catalyze the phosphorylation of phosvitin and casein have been purified... 

Using a similar approach to the isolation of acetyl-CoA carboxylase phosphatase. Lent and Kim (70) isolated a cyclic AMP-independent protein kinase for acetyl-CoA carboxylase (Table IV). The properties of this cyclic AMP-independent protein kinase are different from those reported by Shiao et al. (105). The enzyme had a Km for acetyl-CoA carboxylase of 85 nAf and requires CoA for activity. The significance of this CoA requirement is further discussed in Section V,C. Phos-phorylase b and HMG-CoA reductase do not serve as substrates for this kinase however, protamine, casein, and histones are phosphorylated. The subunit molecular weight, as measured under denaturing conditions, was 160,000, which is similar to that reported by Shiao et al. (105). However, the CoA-requiring enzyme exists in multimers under nondenaturing conditions, with molecular weights between 700,000 and 2 x 10 . 

Recent studies have shown that cyclic AMP-dependent protein kinases are present in many cells, and that these may phosphorylate protamine, histone, casein, phosphorylase kinase, and presumably other proteins as well. Kuo and Greengard (21) have proposed that cyclic AMP mediates all of its actions by activating specific protein kinases in various tissues. The tissue-specific effects of cyclic AMP on a given tissue would then be accounted for in terms of the specific protein kinase and its substrates in that tissue. The apparent Michaelis constants for activation by cyclic AMP are from 2 X 10 Af to 3 X 10 M, and it has been suggested that the... 

An energy-dependent histone phosphorylation was discovered in calf and rat thymus nuclei [68, 69], A histone phosphokinase has been purified from liver, and some of its properties have been studied. The kinase phosphorylates only the serine residues of histones or protamines. It is inactive on other proteins and therefore different from the typical phosphopro-tein kinase. In vitro the enzyme phosphorylates all histone fractions, but FI appears to be a preferred substrate. 

Phosphorylation of histones is another mechanism for the neutralization of basic proteins. The phosphorylation reaction occurs after the completion of the histone synthesis. It is reversible. Phosphorylation of the lysine- and arginine-rich histones precedes an increase in RNA synthesis. This was found in transforming lymphocytes, in the regenerating liver and pancreas, etc. Histones and protamines are phosphorylated at the final stages of spermatogenesis (see review of Allfrey et al, 1964, 1972). Specific kinases which participated in the transport of phosphorus groups from ATP to histones are stimulated by cyclic AMP (Allfrey et al., 1972). 

Langan, T. a.. Smith, L. K. Phosphorylation of histones and protamines by a specific protein kinase from liver. Fed. Proc. 26, 603 (1967). 

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