Histones protamines

Next, we compared the acceptor specificities with regard to the release of nicotinamide and formation of ADP-ribose-protein adducts. As can be seen in Table 2, in addition to histones, protamine, casein, phosvitin, poly-L-arginine, agmatine, and arginine methyl ester also served as acceptors for the ADP-ribosylation. The concentrations of each acceptor were adjusted to give the maximum ADP-ribosylation. With... 

Chromatin and chromosomes are composed mainly of DNA, RNA and numerous proteins. Important enzyme proteins are DNA-polymerase for DNA-repli-cation, and RNA-poIymerase for transcription. Other chromosomal proteins (histones, protamines and acidic proteins) are engaged in the regulation of replication and transcription (see Chromosomes). 

Isolated nuclei are highly permeable to histones, protamines and other biological macromolecules, whereas ATP and Na become tightly bound. The chief components of isolated and disrupted nuclei are DNA-histone complexes (nucleohistones), ribonucleic acids and poorly soluble acidic proteins (residual proteins). Nuclei also contain high concentrations of an arginase and an adenosine S -phosphata e of unknown function. 

There are at least three types of chromosomal proteins histones, protamines, and residual proteins [58-63]. It has been estimated that the nuclear histones represent 90-92% of the total protein in the chromosome. The remaining portion (8-10%) is composed of the residual protein, or non histone proteins. 

The nucleoproteins of the nuclei of trout, salmon and herring sperm, are made up almost entirely of protamine and desoxyribonucleic acid. The nucleoproteins of thymus are made up of desoxyribonucleic acid (40%), ribonucleic acid (1-2%), histones and non-basic proteins. The cellular nuclei contain chiefly desoxyribonucleic acid but, in addition, there is a little ribonucleic acid (in the nucleolus and chromosomes). The cytoplasmic nucleoproteins in general contain only ribonucleic add assodated with proteins which do not have the basic properties of those joined to desoxyribonucleic acid. But the reproductive cell of animals (oocytes) contain desox5rribonudeic add in the cytoplasm. The desoxyribonucleic add of the chromosomes is combined with histones, protamines, and a protein of the usual t3rpe, which is referred to as residual protein. 

Huang et al., (1964) first reported that, unlike histone, protamine did not inhibit DNA-dependent RNA synthesis however, all later results have shown that protamine strongly inhibits DNA-dependent RNA synthesis (Skalka et al., 1966 Suzuki and Ando, 1969). Suzuki and Ando (1969) investigated the effect of the three homogeneous components of clupeine on DNA-dependent RNA synthesis using Escherichia... 

CfiHqNaO . M.p. 277 C. The naturally occurring substance is laevorotatory. Histidine is one of the basic amino-acids occurring in the hydrolysis products of proteins, and particularly of the basic proteins, the protamines and histones. It is an essential constituent of the food of animals. 

H2N-CH2 [CH2j3.CH(NH2) COOH. Colourless needles, m.p. 224 C (decomp.), very soluble in water, insoluble in alcohol. L-(-H)-Lysine is one of the basic amino-acids occurring in particularly large quantities in the protamine and histone classes of proteins. It is an essential amino-acid, which cannot be synthesized by the body and must be present in the food for proper growth. It can be manufactured by various fermentation processes or by synthesis. 

Nucleoproieins. The prosthetic group of the nucleoproteins is nucleic acid, often linked through salt linkages with protamines or histones. The nucleoproteins are present in the nuclei of all cells. Chromasomes are largely nucleoproteins and some plant viruses and bacteriophages have been shown to be pure nucleoproteins. See also histones. 

Protamines, among the smallest proteins with a molecular mass of 5000 dal-tons. They have a high basicity and are foimd in sperm Histones, which also have a high basicity and are found in combination with nucleic acid... 

The first cell cycle of the mouse embryo differs in many respects from the second and the following cell cycles. It is characterized by a long Gl phase that starts after the penetration of the spermatozoon or artificial activation of the oocyte. During this period the chromatin of the oocyte completes the second meiotic division and forms the female pronucleus. At the same time, in the fertilized egg, the highly condensed chromatin of the sperm nucleus decondenses and sperm-specific proteins, protamines, are replaced by histones. After the initial sperm chromatin... 

The weakly immunogenic protamine sulfate USP (1) condenses DNA to form a toroid structure of super-coiled DNA about 50 nm in diameter (2). The DNA in this form or in the preformed LPDI complex cannot be displaced from the protamine by polycations such as spermidine and histones or by other nucleic acids like genomic DNA (2). DNA in this toroid structure is transcriptionally inactive and this conformation allows for protection of DNA from enzymatic degradation by nucleases and other environmental assaults such as mechanical stress (1,2). After the liposome surrounds the toroid, the resulting homogenous LPDI nanoparticles are slightly less than... 

In mammals the histones are removed and replaced by transition basic proteins in mid-spermatids and then the transition basic proteins are replaced by protamines in late spermitids and sperm [119]. In mouse and rat sperm, histones removal is complete or nearly so [119,120], but in humans 15% of the DNA remains associated with histones [121]. In bovine sperm more than 99% of the histones are removed, but CENP-A is quantitatively retained [122]. This retained CENP-A could be part of an epigenetic mark that allows the positions of the centromeres to be retained in sperm and on the paternal chromosomes of the zygote. 

Beyond the modulation of eukaryotic gene expression, histone acetylation has also been functionally linked to histone deposition during DNA replication (see Ref. [146] for a review) and in the displacement/replacement of histones by protamines during spermiogenesis in those vertebrate (see Ref. [147] for a review) and invertebrate organisms [148] whose sperm chromatin consists of protamines [118]. 

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. 

Except the protamines, the histones and the derivatives of the proteins, all the proteins contain carbon, hydrogen, nitrogen, sulphur and oxygen, and they possess the following elementary composition —... 

The protamines are built up almost exclusively of diamino acids, salmine containing over 80 per cent, of arginine. Only small amounts of monoamino acids are present in them, and even these amounts may be due to impurity, for fish sperm only at maturity is made up of protamine and nucleic acid, whereas at other times histone takes the place of protamine, and histones contain less diamino acids. Kossel and Dakin s analysis appears to show us a quantitative result in the case of salmine. 

The histones contain about 30 per cent, of diamino acids, and only in the case of thymus-histone has an estimation been made of the monoamino acids. They were supposed to be intermediate compounds between protamines and other proteins, and this supposition is confirmed by the results of analysis. 

It has been reported that the plasmid vector is unable to translocate to the nucleus unless complexed in the cytoplasm with nuclear proteins possessing NLS. NLS are short karyophilic peptides on proteins that bind to specific transporter molecules in the cytoplasm, mediating their passage through the pore complexes to the nucleus. Examples of these peptides will be given later in this section. DNA can also be presented to cells in culture as a complex with polycations such as polylysine, or basic proteins such as protamine, total histones or specific histone fractions (110), cationized albumin, and others. These molecules increase the transfection efficiency. In addition histone HI is identified as transfection-enhancing protein in cell culture (111). 

In a study of the inhibition of components of the cytochrome systems by maeromolecular poly-ions, Person and Fine205-20 showed that such polycations as protamine sulfate, histone, and ribonuclease inhibit the cytochrome oxidase activity of various systems. The inhibition could be reversed by the addition- of poly-ions (and, especially, by polyglucose sulfate) the latter was also shown to inhibit the oxidase system reversibly. 

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