scholarly journals Preparation of the cellulase from the cellulolytic anaerobic rumen bacterium Ruminococcus albus and its release from the bacterial cell wall

1982 ◽  
Vol 205 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Thomas M. Wood ◽  
Catriona A. Wilson ◽  
Colin S. Stewart
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
High Molecular Weight ◽  
Bacterial Cell ◽  
Phosphate Buffer ◽  
Rumen Fluid ◽  
Extracellular Enzyme ◽  
Rumen Bacterium ◽  
Low Molecular Weight ◽  
Ruminococcus Albus

1. Most of the cellulase (CM-cellulase) elaborated by the rumen bacterium Ruminococcus albus strain SY3, which was isolated from a sheep, was cell-wall-bound. 2. The enzyme could be released readily by washing either with phosphate buffer or with water. 3. The amount of enzyme released was affected by the pH and ionic strength of the phosphate buffer. 4. The cell-wall-bound enzyme was of very high molecular weight (»1.5×106) as judged by its chromatographic behaviour on Sephacryl S-300. 5. The molecular weight of the extracellular enzyme was variable and depended on the culture conditions. 6. When cellobiose was used as the energy source and the medium contained rumen fluid (30%), the extracellular enzyme was, in the main, of high molecular weight. 7. When cellulose replaced the cellobiose, the cell-free culture filtrate contained only low-molecular-weight enzyme (Mr approx. 30000) in late-stationary-phase cultures (7 days). 8. Cultures that did not contain rumen fluid contained mainly low-molecular-weight enzyme. 9. Under some conditions the high-molecular-weight enzyme could be broken down to some extent into low-molecular-weight enzyme by treatment with dissociating agents. 10. Cell-free and cell-wall-bound enzymes showed the same relationship when the change in fluidity effected by them on a solution of CM-cellulose was plotted against the corresponding increase in reducing sugars, suggesting that the enzymes were the same. 11. It is possible that R. albus cellulase exists as an aggregate of low-molecular-weight cellulase components on the bacterial cell wall and in solution under certain conditions.

scholarly journals Yeast cell-wall synthesis

1969 ◽  
Vol 115 (2) ◽  
pp. 231-240 ◽  
Author(s):  
R. Sentandreu ◽  
D. H. Northcote
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Yeast Cell ◽  
High Molecular Weight ◽  
Peptide Synthesis ◽  
Yeast Cell Wall ◽  
Low Molecular Weight ◽  
Cell Wall Synthesis

1. A study of wall synthesis has been made by following the incorporation of radioactive glucose and threonine into the cytoplasm and wall of yeast. 2. Both glucose and threonine are incorporated into a mannan glycopeptide. The glucose is also synthesized into a structural glucan of the wall. 3. The mannan glycopeptide contains high-molecular-weight mannan and low-molecular-weight mannose and oligosaccharide units composed of mannose. Both types of carbohydrate are attached to the peptide. The extent of radioactive incorporation into these different carbohydrate constituents of the glycopeptide remained constant during a pulse-chase experiment. No evidence of a sequential synthesis of oligosaccharides and high-molecular-weight mannan was obtained. 4. Cycloheximide inhibits the incorporation of threonine into the wall but only partially inhibits the incorporation of glucose. Thus not all the polysaccharide deposited into the wall is dependent on a simultaneous peptide synthesis and incorporation. 5. Protoplasts grown in an iso-osmotic medium secreted a mannan polymer that was probably a glycopeptide.

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

scholarly journals Antiparasitic antibodies occur with similar frequency in patients with clinically established multiple sclerosis with or without oligoclonal bands in the cerebrospinal fluid

2013 ◽  
Vol 71 (8) ◽  
pp. 512-515 ◽  
Author(s):  
Fabiana Cruz Gomes da Fonseca-Papavero ◽  
Dagoberto Callegaro ◽  
Paulo Diniz da Gama ◽  
Jose Antonio Livramento ◽  
Adelaide Jose Vaz ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Hygiene Hypothesis ◽  
Oligoclonal Bands ◽  
Parasitic Infections ◽  
Low Molecular Weight ◽  
Serum Samples ◽  
Similar Frequency ◽  
Electrophoresis Of Proteins

The "hygiene hypothesis" postulates an inverse relationship between the prevalence of parasitic infections and the frequency of multiple sclerosis (MS). Objective: It was to study whether antibodies against parasites could be demonstrated more frequently in blood serum from MS patients with oligoclonal bands (OCB) than from MS patients without OCB. Methods: We studied serum samples from 164 patients who had previously been analyzed to investigate OCB. Parasitic antibodies were studied through unidimensional electrophoresis of proteins on polyacrylamide gel against Taenia antigens, searching for antiparasitic specific low molecular weight antibodies and also for antiparasitic nonspecific high molecular weight antibodies. Results: Two of the 103 patients with no evidence of OCB had antibodies of low molecular weight and 59 of them had antibodies of high molecular weight. Of the 61 patients with evidence of OCB, one showed antibodies of low molecular weight and 16 showed antibodies of high molecular weight. Conclusion: Antiparasitic antibodies are detected with similar frequency in MS patients with OCB and in MS patients without OCB.

Simultaneous Isolation of Wheat High Molecular Weight and Low Molecular Weight Glutenin Subunits

1998 ◽  
Vol 28 (1) ◽  
pp. 25-32 ◽  
Author(s):  
I.M. Verbruggen ◽  
W.S. Veraverbeke ◽  
A. Vandamme ◽  
J.A. Delcour
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Glutenin Subunits

scholarly journals The interrelations between high- and low-molecular-weight forms of normal and mutant (Krabbe-disease) galactocerebrosidase

1980 ◽  
Vol 189 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Yoav Ben-Yoseph ◽  
Melinda Hungerford ◽  
Henry L. Nadler
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Active Form ◽  
Sodium Dodecyl ◽  
Krabbe Disease ◽  
Low Molecular Weight ◽  
Molecular Weight Form

Galactocerebrosidase (β-d-galactosyl-N-acylsphingosine galactohydrolase; EC 3.2.1.46) activity of brain and liver preparations from normal individuals and patients with Krabbe disease (globoid-cell leukodystrophy) have been separated by gel filtration into four different molecular-weight forms. The apparent mol.wts. were 760000±34000 and 121000±10000 for the high- and low-molecular-weight forms (peaks I and IV respectively) and 499000±22000 (mean±s.d.) and 256000±12000 for the intermediate forms (peaks II and III respectively). On examination by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the high- and low-molecular-weight forms revealed a single protein band with a similar mobility corresponding to a mol.wt. of about 125000. Antigenic identity was demonstrated between the various molecular-weight forms of the normal and the mutant galactocerebrosidases by using antisera against either the high- or the low-molecular-weight enzymes. The high-molecular-weight form of galactocerebrosidase was found to possess higher specific activity toward natural substrates when compared with the low-molecular-weight form. It is suggested that the high-molecular-weight enzyme is the active form in vivo and an aggregation process that proceeds from a monomer (mol.wt. approx. 125000) to a dimer (mol.wt. approx. 250000) and from the dimer to either a tetramer (mol.wt. approx. 500000) or a hexamer (mol.wt. approx. 750000) takes place in normal as well as in Krabbe-disease tissues.

Influence of Dipeptide Structure on Hydrolysis by Rumen Fluid and Blood of Sheep

1996 ◽  
Vol 1996 ◽  
pp. 177-177
Author(s):  
M D Mesgaran ◽  
D S Parker
Keyword(s):  
Molecular Weight ◽  
Rumen Fluid ◽  
Hydrolysis Rate ◽  
Low Molecular Weight ◽  
Intermediate Step ◽  
Disappearance Rate ◽  
Tissue Metabolism ◽  
Ruminal Digestion

The ruminal digestion of protein results in the production of peptides (3) which are an intermediate step in the conversion of ingested protein to ammonia. Low molecular weight peptides can also act as substrate for tissue metabolism (2). While it has been shown that low molecular weight peptides are present in ruminant blood (4), their hydrolysis rate has not been investigated. The following in vitro study was conducted to investigate the disappearance rate from blood and rumen fluid of sheep of two different dipeptides; glycylproline and glycylphenylalanine.

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.

Calcium-Dependent Cross-Linking Processes in Platelets

1979 ◽  
Author(s):  
I. Cohen ◽  
T. Glaser
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Tracer Concentration ◽  
Calcium Dependent ◽  
A 23187 ◽  
Polymer Formation ◽  
Total Disappearance ◽  
Low Molecular Weight Proteins

When platelet cytoplasmic Ca2+ is increased by the ionophore A 23187, there is the coincident appearance of a cross-linked polymer and the partial disappearance of five high molecular weight polypeptide bands (> 145,000). The glycoproteins show a partial disappearance of bands lb, IIb and IV and the total disappearance of hands la and Ilia. The disappearance of the protein bands, possibly contributing to the polymer formation, is prevented by histamine, aminoacetonltrile and cystamlne, which, as pseudodonor amines are known Inhibitors of factor XHIa-catalyzed cross-linking. 14C-histamine, at a tracer concentration, was incorporated into the polymer as well as into myosin, glycoproteins IIb and IIIa (α-actinln), actin and two unidentified low-molecular weight proteins. The polymer formed is also apparent in isolated membranes following the iono-phore-stimulated increase in intracellular Ca2+. These findings are unrelated to a proteolytic activity since the platelet Ca2+-dependent proteases are inhibited by leupep-tin. Ca2+-activation of a platelet cytosol transamidase would explain the data obtained. This platelet transamidase(s) may couple membrane proteins to cytoplasmic contra-tlle proteins. Thus, a new concept is proposed for the stabilization of platelet membranes and platelets as they form the hemostatic plug.

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