Poly(ADP-ribose) accessibility to poly(ADP-ribose) glycohydrolase activity on poly(ADP-ribosyl)ated nucleosomal proteins

1986 ◽  
Vol 64 (2) ◽  
pp. 146-153 ◽  
Author(s):  
A. Gaudreau ◽  
L. Ménard ◽  
G. de Murcia ◽  
G. G. Poirier
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Histone H1 ◽  
Enzyme Complex ◽  
Electron Microscopic ◽  
Histone H2b ◽  
Polymer Hydrolysis ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of ◽  
Substrate Concentrations

Hydrolysis of protein-bound 32P-labelled poly(ADP-ribose) by poly(ADP-ribose) glycohydrolase shows that there is differential accessibility of poly(ADP-ribosyl)ated proteins in chromatin to poly(ADP-ribose) glycohydrolase. The rapid hydrolysis of hyper(ADP-ribosyl)ated forms of histone H1 indicates the absence of an H1 dimer complex of histone molecules. When the pattern of hydrolysis of poly(ADP-ribosyl)ated histones was analyzed it was found that poly(ADP-ribose) attached to histone H2B is more resistant than the polymer attached to histone H1 or H2A or protein A24. Polymer hydrolysis of the acceptors, which had been labelled at high substrate concentrations (≥ 10 μM), indicate that the only high molecular weight acceptor protein is poly(ADP-ribose) polymerase and that little processing of the enzyme occurs. Finally, electron microscopic evidence shows that hyper(ADP-ribosyl)ated poly(ADP-ribose) polymerase, which is dissociated from its DNA–enzyme complex, binds again to DNA after poly(ADP-ribose) glycohydrolase action.

scholarly journals Biodegradation of low molecular weight polyacrylamide under aerobic and anaerobic conditions: effect of the molecular weight

2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Carbon Chain ◽  
Anaerobic Treatment ◽  
Low Molecular Weight ◽  
Amino Groups ◽  
Molecular Weights ◽  
Weight One ◽  
Hydrolysis Of ◽  
Aerobic And Anaerobic

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.

scholarly journals Ca2+-Induced Cleavage of Human Platelet Polypeptides Mediated by the Calcium Ionophore A-23187

1977 ◽  
Author(s):  
Milica Jakábová ◽  
David R. Phillips
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Proteolytic Activity ◽  
Platelet Activation ◽  
Human Platelet ◽  
Calcium Ionophore ◽  
Lactic Dehydrogenase ◽  
Actin Binding ◽  
A 23187 ◽  
Hydrolysis Of

The effect of calcium on human platelet polypeptides was investigated. When lysed platelets were incubated with mM Ca++, two major intracellular polypeptides (Mr = 255,000 and 230,000) were found to rapidly disappear. A similar phenomenon was also observed when intact platelets were treated with the calcium ionophore A-23187 in the presence of mM Ca++. Determinations of lactic dehydrogenase activity in supernatant fractions demonstrated that these losses occurred before platelet lysis. Investigations into the identity of the high molecular weight polypeptides revealed that one (Mr = 255,000) had similar properties to actin binding protein. The loss of the high molecular weight polypeptides was accompanied by formation of lower molecular weight polypeptides (Mr = 135,000, 93,000 and 48,000), indicating that Ca++ activates a polypeptide cleavage mechanism. The Ca++-activated polypeptide cleavages were rapid, with significant changes being observed within the first 0.5 min of incubation. An obvious explanation for these effects is. that there is Ca++-activated proteolytic activity within platelets. The Ca++-activated proteolytic activity was determined by the hydrolysis of the artificial substrate azocasein. We found that more than 90% of the proteolytic activity in lysed platelets was due to Ca++-activated proteases. These studies show that Ca++-activated proteases may play an important role in platelet activation.

Autolysis of Penicillium oxalicum with special reference to its cell walls

1982 ◽  
Vol 28 (12) ◽  
pp. 1289-1295 ◽  
Author(s):  
M. I. Perez-Leblic ◽  
Fuensanta Reyes ◽  
R. Lahoz ◽  
S. A. Archer
Keyword(s):  
Cell Walls ◽  
Schizophyllum Commune ◽  
Dry Weight ◽  
Penicillium Oxalicum ◽  
Lytic Enzyme ◽  
Enzyme Complex ◽  
Fungal Cell ◽  
Rapid Hydrolysis ◽  
And Storage ◽  
Hydrolysis Of

Cultures of Penicillium oxalicum growing on a denned medium supplemented with yeast extract reached the onset of autolysis after 3 days at 25 °C. Thenceforth, autolysis was progressive and eventual reductions in dry weight of 96% were recorded by day 47. The pH of the medium fluctuated between 4.0 during the exponential phase of growth and 9.0 during autolysis. Electron microscopy of autolyzing cultures revealed a progressive loss of cytoplasmic ultrastructure. Digestion of the cell walls, with a rapid hydrolysis of the three external layers and a low hydrolysis of the two inner layers, was accompanied by deep pitting and by loss of the distinct five-layered structure. A lytic enzyme complex was obtained from the filtrates of extensively autolyzed cultures. It was rich in (1 → 3)-β-glucanase and other enzymes active against a range of fungal cell wall and storage polysaccharides. This enzyme complex degraded extensively isolated cell walls of P. oxalicum and three other Ascomycetes but had less effect on walls isolated from Mucor mucedo or Schizophyllum commune. In the case of P. oxalicum, cell walls harvested from young cultures were more readily digested than were the walls from older cultures.

"Colloidal" Phosphorus Errors in Gel Chromatography

1983 ◽  
Vol 40 (10) ◽  
pp. 1614-1621 ◽  
Author(s):  
B. Kent Burnison
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
High Molecular Weight ◽  
Gel Chromatography ◽  
Chemical Analyses ◽  
Molybdophosphoric Acid ◽  
Molybdenum Blue ◽  
Soluble Reactive Phosphate ◽  
Colloidal Phosphorus ◽  
Hydrolysis Of

Gel chromatography has been used for the separation of 32PO4 and a high molecular weight "colloidal" 32P-labeled fraction from 32PO4-labeled lakewater. When the labeled filtrate is treated with reagents required for the molybdenum blue method for orthophosphate analysis, only a small fraction of the "colloidal" peak is hydrolyzed to orthophosphate. As the reduced molybdophosphoric acid is strongly adsorbed to the dextran gel, quantitative elution of 32PO4 can be achieved with 0.05 mol∙L−1 NaOH and 0.3% NaCl. In hardwater lakes, care must be taken to eliminate the possibility of orthophosphate precipitation at higher pH. In these lakes, it is unlikely that the discrepancy between 32PO4 bioassays and chemical analyses can be solely attributed to acid hydrolysis of "colloidal" phosphorus. Microparticulate apatite also has the potential to release soluble reactive phosphate when the acidic molybdenum blue method is used.

END GROUP AND SEDIMENTATION DATA ON FRAGMENTED HIGH MOLECULAR WEIGHT RIBONUCLEATES

1963 ◽  
Vol 41 (1) ◽  
pp. 1927-1941 ◽  
Author(s):  
B. G. Lane ◽  
J. Diemer ◽  
C. A. Blashko
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Snake Venom ◽  
Group Analysis ◽  
Sedimentation Coefficient ◽  
Snake Venom Phosphodiesterase ◽  
Ehrlich Ascites ◽  
Spontaneous Hydrolysis ◽  
Hydrolysis Of ◽  
End Group

A method for end group analysis of ribonucleate preparations using purified snake venom phosphodiesterase is described. Unusual difficulties encountered with the method are discussed. The technique is useful for detection of end groups resulting from enzymic and chemical fragmentation of high molecular weight ribonucleates. Preliminary studies indicate that the method has limited usefulness because of a spontaneous hydrolysis of ribonucleates which occurs under the conditions which are optimal for hydrolysis with snake venom phosphodiesterase (pH 9, in the presence of magnesium). Physicochemical studies have shown that the pronounced dependence of sedimentation coefficient on ionic strength which has been reported by other investigators is also observed with fragmented high molecular weight ribonucleates and with 16S + 24S ribonucleates of Ehrlich ascites cells. The changes of sedimentation rate are associated with configurational and aggregation effects.

Distribution of radioactive silver in the subcellular fractions of various tissues of the rat and its binding to low molecular weight proteins

1983 ◽  
Vol 61 (11) ◽  
pp. 1391-1395 ◽  
Author(s):  
Yousef Matuk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Total Radioactivity ◽  
Subcellular Fractions ◽  
Low Molecular Weight ◽  
Electron Microscopic ◽  
Molecular Weight Peak

In view of the electron microscopic evidence that silver does not penetrate cellular barriers, the distribution of radioactive silver in rat blood and subcellular fractions of liver, kidneys, spleen, and forebrain was studied. It was found that 24 h after a single intraperitoneal injection high levels of radioactivity were reached which decreased at different rates in the various tissues studied. In plasma, liver, and kidneys there was an initial rapid loss of radioactivity which was followed by a slower rate of loss. In the blood, forebrain, and spleen the loss of radioactivity was linear and somewhat slower than in the other three tissues. The cytosols of the liver and kidneys contained 60% while those of the forebrain and spleen contained 30% of the total radioactivity found in the tissue homogenates. Gel filtration on Sephadex G-75 showed that all cytosols contained two peaks of radioactivity; a high molecular weight peak which eluted just after the void volume and a low molecular weight peak. The amount of radioactivity in both peaks was, however, much lower in the chromatographic peaks of the forebrain and spleen than that found in those of the liver and kidneys. Furthermore, the spleen had a comparatively very small low molecular weight radioactive peak. In vitro experiments with liver cytosol showed similar results to those found in vivo in that the high molecular weight radioactive peak could be removed by heat. It is concluded that silver does enter cells and that silver thionein exists in the cytosols of forebrain, spleen, kidney, and liver.

scholarly journals Structure and Capsid Association of the Herpesvirus Large Tegument Protein UL36

2010 ◽  
Vol 84 (18) ◽  
pp. 9408-9414 ◽  
Author(s):  
William W. Newcomb ◽  
Jay C. Brown
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Microscopic Analysis ◽  
Molecular Weight Protein ◽  
High Molecular Weight Protein ◽  
Electron Microscopic ◽  
Tegument Proteins ◽  
Weight Protein ◽  
Simplex Virus

ABSTRACT The tegument of all herpesviruses contains a high-molecular-weight protein homologous to herpes simplex virus (HSV) UL36. This large (3,164 amino acids), essential, and multifunctional polypeptide is located on the capsid surface and present at 100 to 150 copies per virion. We have been testing the idea that UL36 is important for the structural organization of the tegument. UL36 is proposed to bind directly to the capsid with other tegument proteins bound indirectly by way of UL36. Here we report the results of studies carried out with HSV type 1-derived structures containing the capsid but lacking a membrane and depleted of all tegument proteins except UL36 and a second high-molecular-weight protein, UL37. Electron microscopic analysis demonstrated that, compared to capsids lacking a tegument, these capsids (called T36 capsids) had tufts of protein located at the vertices. Projecting from the tufts were thin, variably curved strands with lengths (15 to 70 nm) in some cases sufficient to extend across the entire thickness of the tegument (∼50 nm). Strands were sensitive to removal from the capsid by brief sonication, which also removed UL36 and UL37. The findings are interpreted to indicate that UL36 and UL37 are the components of the tufts and of the thin strands that extend from them. The strand lengths support the view that they could serve as organizing features for the tegument, as they have the potential to reach all parts of the tegument. The variably curved structure of the strands suggests they may be flexible, a property that could contribute to the deformable nature of the tegument.

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