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Molecular phylogeny and evolution of marsupial protamine P1 genes.

We report the DNA sequences of protamine P1 genes and flanking regions from 21 mammalian species, including representatives of all extant marsupial orders. The protamine P1 locus in marsupials displays highly conserved 5' and 3' flanking sequences, as well as a highly variable intron. Marsupial protamines examined are distinct from those of eutherian mammals in lacking cysteine residues, a feature that may be correlated with lower stability of marsupial sperm nuclei during chromatin condensation. Phylogenetic analysis of protamine sequences leads to the following conclusions: (i) the microbiothere Dromiciops is part of a clade that includes dasyurids, Notoryctes and diprotodontians but not bandicoots; (ii) dasyurids are the closest living relatives of Notoryctes; (iii) macropodids, phalangerids and pseudocheirids form a clade apart from the phascolarctids; and (iv) the closest living relatives of caenolestids are didelphids.

Amino Acid Sequence↗

Proteins from the sperm of the bivalve mollusc Ensis minor. Co-existence of histones and a protamine-like protein.

Analysis of the total protein of the mature sperm of the bivalve mollusc Ensis minor (razor shell) using gel electrophoresis, amino acid analysis, nuclear magnetic resonance, circular dichroism and trypsin digestion, show it to contain all five histones plus a protamine-like protein. The histones H3, H4 and probably H2A are similar to those from calf thymus or sea urchin sperm, but the putative H2B appears to have a very high molecular mass (about 20 kDa). The histone H1 molecule is unusual, having little or no proline and 8-10 residues of histidine. The protamine-like species is rich in both lysine as well as arginine and is of much higher molecular mass than fish sperm protamines. Nucleosomes containing the four core histones have been prepared and the nucleosomal repeat shown to be 200 +/- 5 base pairs. Checks for the absence of contaminating cells reinforce the conclusion that a histone-containing nucleosomal structure co-exists with a protamine-like protein in this sperm chromatin.

Amino Acids↗

Cuttlefish sperm protamines. 1. Amino acid sequences of two distinct variants.

The amino acid sequences of two cuttlefish protamine variants Sp1 and Sp2 have been established from automated sequence analysis and mass spectrometry data. Sp1 (57 residues) and Sp2 (56 residues) have molecular masses of 8410 and 8253 Da, respectively. They are almost identical proteins which differ only by one residue of arginine and the position of two of the serine residues (14 and 37 in Sp1; 13 and 35 in Sp2). With an arginine content of about 77%, cuttlefish protamine is one of the most basic proteins which have ever been characterized and the first typical protamine sequenced in invertebrates. It is closely similar to sperm basic proteins identified in squids but strongly differs from the protamine-like components isolated from the sperm of bivalve molluscs.

Amino Acid Sequence↗

Relationship between protamine deficiency with fertilization rate and incidence of sperm premature chromosomal condensation post-ICSI.

After aneuploidy, sperm premature chromatin condensation (PCC) is the next prevalent cause of fertilization failure. Therefore the aim of this study was to evaluate the effect of sperm protamine deficiency on sperm PCC formation post-ICSI. Chromatin analysis was carried out on failed fertilized oocytes post-ICSI and incidences of sperm PCC were evaluated and the results were compared with the extent of protamine deficiency assessed by chromomycin A3. The results show that incidence of sperm PCC was significantly different in failed fertilized oocytes injected from semen samples with greater or less than 30% CMA3 positivity (P = 0.04). However, except for fertilization rate (P < 0.001), the mean number of MII, MI and germinal vesicles oocytes and percentage normal sperm were not significantly different between the two groups (P > 0.05). A significant correlation was observed between sperm protamine deficiency with fertilization rate. Hence sperm protamine deficiency affects fertilization rate and possibly prones sperm to PCC post-ICSI.

Adult↗

Protamine precipitation of two reovirus particle types from polluted waters.

Two forms of virus particle are released from reovirus-infected cell cultures, infectious reovirus and potentially infectious reovirus (PIV). PIV particle forms have a complete outer coat and are not infectious until the outer coat is altered or removed. The PIV concentration in polluted waters, however, has not been determined. Protamine sulfate precipitation, using 0.25% fetal bovine serum and 0.005% protamine sulfate for the first precipitation of the sample and 0.0025% for the second, was employed to concentrate infectious reovirus and PIV from water and sewage. Infectious reovirus and PIV particles were concentrated over 500-fold from river water inoculated with virus, and virus recoveries of between 80 and 100% were achieved. Virus precipitates stored at -20 degrees C as a protamine-virus concentrate showed a 5% loss of PIV after 14 days. Virus preparations were assayed, before and after treatment, with 200 micrograms of chymotrypsin per ml, using a fluorescent-antibody procedure. Protamine sulfate precipitation and fluorescent-antibody detection are effective ways to recover and assay reoviruses present in raw sewage.

Chemical Precipitation↗

Inhibitory effects of protamines on proteolytic and adhesive activities of Porphyromonas gingivalis.

Protamines (salmine prepared from sperm DNA of salmon and clupeine from herring sperm), which are basic peptides rich in arginine, were found to inhibit the proteolytic activity of arginine-specific cysteine protease (RC-protease) from Porphyromonas gingivalis. Lineweaver-Burk plot analysis revealed that the protamines competitively inhibited proteolytic activity with cleavage of benzoyl-L-arginine-p-nitroanilide, a synthetic substrate of RC-protease. Furthermore, the protamines were capable of binding strongly to P. gingivalis fimbriae and inhibited fimbrial interaction with immobilized fibronectin. These results clearly show that protamines are potent inhibitors of the proteolytic and adhesive activities of P. gingivalis.

Adhesins, Bacterial↗

Transfection of Escherichia coli spheroplasts. I. General facilitation of double-stranded deoxyribonucleic acid infectivity by protamine sulfate.

The addition of 25 mug of protamine sulfate per ml to lysozyme-ethylenediamine-tetraacetic acid spheroplasts of Escherichia coli stimulates transfection not only for T1 phage deoxyribonucleic acid (DNA; Hotz and Mauser, 1969) but also for the following phage DNA species: lambda, 10,000-fold to an efficiency of 10(-3) infective centers per DNA molecule; phiX174 replicative form, 300-fold to an efficiency of 5 x 10(-2); fd replicative form, 300-fold to 10(-6); T7, 300-fold to 3 x 10(-7). Three native phage DNA species were not infective at all in the absence of protamine sulfate but were infective in the presence of protamine sulfate with the following efficiencies: T4, 10(-5); T5, 3 x 10(-6); and P22, 3 x 10(-9). The effect of protamine sulfate is specific for double-stranded DNA. The application of infectivity assays to the study of phage DNA replication, recombination, prophage integration, prophage excision, and interspecies transfection are discussed.

Centrifugation, Density Gradient↗

Binding of a phosphoprotein to the 3' untranslated region of the mouse protamine 2 mRNA temporally represses its translation.

The synthesis of the protamines, the predominant nuclear proteins of mammalian spermatozoa, is regulated during germ cell development by mRNA storage for about 7 days in the cytoplasm of differentiating spermatids. Two highly conserved sequences, the Y and H elements present in the 3' untranslated regions (UTRs) of all known mammalian protamine mRNAs, form RNA-protein complexes and specifically bind a protein of 18 kDa. Here, we show that translation of fusion mRNAs was markedly repressed in reticulocyte lysates supplemented with a mouse testis extract enriched for the 18-kDa protein when the mRNAs contained the 3' UTR of mouse protamine 2 (mP2) or the Y and H elements of mP2. No significant decrease was seen when the fusion mRNAs contained the 3' UTR of human growth hormone. The 18-kDa protein is developmentally regulated in male germ cells, requires phosphorylation for RNA binding, and is found in the ribonucleoprotein particle fractions of a testicular postmitochondrial supernatant. We propose that a phosphorylated 18-kDa protein plays a primary role in repressing translation of mP2 mRNA by interaction with the highly conserved Y and H elements. At a later stage of male gamete differentiation, the 18-kDa protein no longer binds to the mRNA, likely as a result of dephosphorylation, enabling the protamine mRNA to be translated.

Animals↗

Histone- and protamine-DNA association: conservation of different patterns within the beta-globin domain in human sperm.

Most DNA in human sperm is bound to highly basic proteins called protamines, but a small proportion is complexed with histones similar to those found in active chromatin. This raises the intriguing possibility that histones in sperm are marking sets of genes that will be preferentially activated during early development. We have examined the chromatin structure of members of the beta-globin gene family, which are expressed at different times in development, and the protamine 2 gene, which is expressed in spermatids prior to the widespread displacement of histones by transition proteins. The genes coding for epsilon and gamma globin, which are active in the embryonic yolk sac, contain regions which are histone associated in the sperm. No histone-associated regions are present at the sites tested within the beta- and delta-globin genes which are silent in the embryonic yolk sac. The trends of histone or protamine association are consistent for samples from the same person, and no significant between-subject variations in these trends are found for 13 of the 15 fragments analyzed in the two donors. The results suggest that sperm chromatin structures are generally similar in different men but that the length of the histone-associated regions can vary. The association of sperm DNA with histones or protamines sometimes changes within as little as 400 bp of DNA, suggesting that there is fine control over the retention of histones.

Binding Sites↗

A study of two methods for estimating plasma fibrinogen and the effect of epsilon aminocaproic acid and protamine.

Fibrinogen concentrations were determined in normal plasma and in plasma from patients with high and low levels. There was a good correlation between the results of a rapid semi-quantitative fibrinogen titre technique and those of a quantitative assay of coagulable fibrinogen. In normal subjects fibrinogen levels were not significantly influenced by taking blood into epsilon aminocaproic acid (EACA) or by the addition of protamine to plasma. In patients with the defibrination syndrome in whom increased plasma fibrinolysis was not detected, fibrinogen levels were not affected by taking blood into EACA but considerably increased levels were observed after the addition of protamine to plasma. In patients undergoing thrombolytic therapy the fibrinogen levels measured were increased both in blood taken into EACA and in plasma containing protamine. It is suggested that EACA acted by preventing lysis in vitro whilst protamine counteracted abnormal fibrin polymerization. The pattern of results may be of diagnostic importance.

Aminocaproates↗

Development of protamine hollow-fiber device for extracorporeal heparin removal.

Protamine was covalently coupled to a cellulose hollow fiber (cuprophan membrane) through epichlorohydrin-activated hydroxyl groups on the hollow fiber. An immobilization efficiency of as much as 15 mg protamine/g fiber could be achieved under optimal reacting conditions. Compared to a protamine hollow-fiber device produced using cyanogen bromide as an activator, the protamine hollow-fiber device using epichlorohydrin as an activator shows very high resistance to hydrolysis. Both in vitro and in vivo experiments showed that such a protamine hollow-fiber device had high heparin-removal capacity and efficiency, suggesting that this device may be suitable for various clinical applications in extracorporeal heparin removal.

Adsorption↗

Incomplete reversal of enoxaparin-induced bleeding by protamine sulfate.

The neutralizing effect of protamine sulfate on enoxaparin-induced bleeding was compared in two rat models: one employing the gastric mucosa, and the other the tail skin, using a 2:1 ratio of protamine sulfate to enoxaparin on a weight basis. Whereas protamine sulfate reduced the median bleeding time (from 20 to 9.5 min) and blood loss (80%) in the gastric mucosa, and apparent 'all-or-none' response was seen in the tail skin, in agreement with a different hemostatic mechanism in the two bleeding models. In both models, protamine sulfate incompletely reversed the bleeding induced by enoxaparin.

Animals↗

Influence of heparin, protamine and polybrene on the time integral of thrombin generation (endogenous thrombin potential).

We investigated the anticoagulating and heparin-neutralizing properties of protamine and polybrene (hexadimethrine bromide), using the endogenous thrombin potential (ETP) as the parameter to access plasma coagulability. The hypocoagulability induced by high doses of heparin (3 IU/ml) could be reversed by addition of protamine to a very limited extent only. Polybrene on the other hand did neutralize heparin at the equivalent concentration and a two-fold excess did not influence the ETP parameters. In vivo neutralization of high-dose heparin with protamine should therefore be reconsidered. Our experiments suggest polybrene to be superior over protamine with respect to neutralization of high doses of heparin.

Anticoagulants↗

Protamine sulphate inhibits pentasaccharide (SR80027)-induced bleeding without affecting its antithrombotic and anti-factor Xa activity in the rat.

The neutralization of a potent anti-factor Xa pentasaccharide (SR 80027) and heparin-induced bleeding enhancement by protamine sulphate was studied in vivo. Bleeding time, as measured by transection of the tail of anaesthetized rats, increased after the administration of standard heparin and SR 80027. Doses of 0.6 and 2.5 mg/kg of heparin and SR 80027, respectively, were required to enhance blood loss to the same extent (6-fold increase). Protamine sulphate (10 mg/kg i.v.) reduced blood loss induced by both compounds but also neutralized the anti-factor Xa activity as well as the antithrombotic activity of standard heparin measured in a venous thrombosis model. However, protamine sulphate did not affect the anti-factor Xa activity or the antithrombotic activity of SR 80027. These data suggest that protamine sulphate may be an effective antidote for the bleeding side-effects of SR 80027 but they also indicate that the bleeding tendency associated with this type of compounds cannot be attributed to their anti-factor Xa activity.

Animals↗

Complement C5a receptor antagonism by protamine and poly-L-Arg on human leukocytes.

It is shown that protamine selectively and dose-dependently inhibits complement C5a-induced leukocyte responses such as histamine release from basophils, chemiluminescence and beta-glucuronidase release from neutrophils. Protamine produces parallel rightward displacements of the C5a dose-response curves. The inhibitory capacity of the polypeptide is reversible and disappears following repeated washing of exposed cells. In neutrophils poly-L-Arg similarly and specifically antagonizes C5a-induced chemiluminescence and enzyme release. This polymer alone, however, degranulates basophils and neutrophils, leading to histamine and enzyme release, respectively. It is concluded that on human neutrophils the arginine-rich polycations protamine and poly-L-Arg exhibit a competitive C5a receptor antagonism. In addition, protamine inhibits the C5a receptors on basophils. It is hypothesized that molecular conformations of the arginine-rich polycations might bind reversibly to, and block negatively charged groups at the C5a-receptor sites.

Basophils↗

Protamine inhibits capillary formation in growing rat hearts.

Various indices of capillary supply to the rat heart were studied in neonatal rats injected for 2 or 4 weeks with protamine sulfate in saline (subcutaneously, 60 mg/kg body weight, 2 times/day). Cardiac capillarization was evaluated not only by traditional indices for the capillary supply, such as mean capillary density and myocyte-to-capillary ratio, but also by a more advanced morphometric method of capillary domains. This method allows the estimation of both the average radius of the Krogh tissue cylinder and its variability, which reflects the heterogeneity of capillary spacing found to be an independent morphological determinant of oxygen diffusion in the tissue. The results were evaluated with respect to regional differences (subendocardial vs. middle section), age differences, and the effect of protamine. No regional differences in capillary supply were found in this experimental situation. Hearts from older rats had significantly decreased capillary supply, expressed as lower capillary density, larger capillary domains, and greater radius of the tissue cylinder. On the other hand, the heterogeneity of capillary spacing decreased significantly with age. Protamine-injected animals, when compared to their control littermates, had a significantly higher cell-to-capillary ratio, lower capillary density, larger capillary domains, greater radius of the tissue cylinder, and larger variability in capillary spacing. Thus, protamine was effective in impeding rapid capillary growth in the hearts from rats in the early postnatal period. Close to half of all the existing capillaries in the adult rat hearts are formed during the first 3-4 postnatal weeks.

Animals↗

Platelet-activating factor potentiates protamine-induced lung edema. Role of eicosanoids.

Platelet-activating factor (PAF) is a cell membrane-derived ether lipid that plays an important role in acute lung vascular injury. We recently reported that PAF potentiates protamine-induced lung edema by enhancing pulmonary venoconstriction. As PAF is known to stimulate lung eicosanoid synthesis, we investigated the role of peptidoleukotrienes and other eicosanoids in this priming effect of PAF. Addition of PAF (1.6 nM), followed 10 min later by protamine (50 micrograms/ml), to perfusate of salt solution-perfused rat lungs resulted in marked arterial and venous constrictions and severe lung edema. Lung tissue thromboxane B2, 6-ketoprostaglandin F1 alpha and leukotriene C4 (LTC4) were markedly elevated 20 min after PAF/protamine. Pretreatment of the lungs with AA-861, a specific 5-lipoxygenase inhibitor, blocked PAF/protamine-induced leukotriene synthesis, arterial and venous constrictions, and lung edema. In addition, injection of LTC4 (1 microgram) markedly potentiated protamine-induced arterial and venous constrictions and caused lung edema similar to PAF/protamine. Indomethacin, a specific cyclooxygenase inhibitor, also reduced the vasoconstrictive and edemagenic responses to PAF/protamine. However, the pulmonary edema after LTC4/protamine was not blocked by indomethacin. In separate experiments, infusion of this "priming" dose of PAF into isolated perfused lungs induced LTC4 synthesis and augmented lung thromboxane A2 synthesis after arachidonic acid infusion. We conclude that both cyclooxygenase and lipoxygenase products of arachidonic acid metabolism are involved in PAF-induced potentiation of protamine lung edema.

Animals↗

Experimental inhibition of protamine cardiotoxicity by prostacyclin.

Twelve animals (26+/-5 kg) were subjected to the study. In this experimental study, the authors used prostacyclin to inhibit the toxic metabolite release during protamine administration. Animals were divided into two equal groups. Six animals received prostacyclin (the prostacyclin group), and the other six animals did not receive any additional treatment (the control group). All cardiac output and biochemical measurements were evaluated at baseline; before cardiopulmonary bypass; and at 5, 30, and 60 minutes after protamine administration. The measured cardiac index showed that the hearts treated with prostacyclin had satisfactory preservation of left ventricular function. Metabolic and biochemical data showed that the tumor necrosis factor level was raised significantly in the control group (20.75+/-2.2 in the control group and 13.75+/-2.5 pg/mL in the prostacyclin group). Also, E and P selectin levels were elevated in the control group, but this change was less marked in the prostacyclin group. In addition, the intracellular adhesion molecule-1 (ICAM-1) level was significantly higher in the control group than in the prostacyclin group (9.26+/-2.13 in the control group and 5.13+/-1.66 ng/mL in the prostacyclin group). The authors observed that prostacyclin inhibited the toxic mediator release during heparin reversal with protamine. This inhibition is one way of protecting the myocardium reserves from protamine cardiotoxicity.

Animals↗