Effects of Low Molecular Weight Sulfated Galactan Fragments From Botryocladia Occidentalis on the Pharmacological and Enzymatic Activity of Spla2 From Crotalus Durissus Cascavella

2010 ◽  
Vol 29 (8) ◽  
pp. 567-571 ◽  
Author(s):  
M. H. Toyama ◽  
D. O. Toyama ◽  
V. M. Torres ◽  
G. C. Pontes ◽  
W. R. L. Farias ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Activity ◽  
Low Molecular Weight ◽  
Sulfated Galactan ◽  
Crotalus Durissus Cascavella ◽  
Crotalus Durissus

scholarly journals Thermolability of 28S ribosomal ribonucleic acid from the liver of Crotalus durissus terrificus (Ophidia, Reptilia)

1973 ◽  
Vol 135 (1) ◽  
pp. 73-79 ◽  
Author(s):  
J. F. Giorgini ◽  
F. L. De Lucca
Keyword(s):  
Molecular Weight ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sucrose Density Gradient ◽  
Dimethyl Sulphoxide ◽  
Low Molecular Weight ◽  
28S Rrna ◽  
Sucrose Density Gradient Centrifugation ◽  
Crotalus Durissus Terrificus ◽  
Crotalus Durissus

Instability of 28S rRNA of Crotalus durissus terrificus liver was observed during hotphenol extraction: purified 28S rRNA is converted into an 18S RNA component by heat treatment. It was also found that ‘6S’ and ‘8S’ low-molecular-weight RNA species were released during the thermal conversion. This conversion and the release of the low-molecular-weight species were also induced by 8m-urea and 80% (v/v) dimethyl sulphoxide at 0°C. Evidence is presented that this phenomenon is an irreversible process and results from the rupture of hydrogen bonds. The 18S RNA product was shown to be homogeneous by polyacrylamide-gel electrophoresis and by sucrose-density-gradient centrifugation. The base composition of the 18S RNA products obtained by heat, urea or dimethyl sulphoxide treatments was similar. The C+G content of the 18S RNA product was different from that of the native 18S rRNA, but similar to that of 28S rRNA.

Convulxin, An ADP And Thromboxane-Independent Platelet activating Glycoprotein From The Venom Of Crotalus Durissus Cascavella

1981 ◽  
Author(s):  
G Marlas ◽  
D Joseph ◽  
J P Franceschi ◽  
J Lefort ◽  
M Chignard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Guinea Pigs ◽  
Human Platelets ◽  
Metal Chelation ◽  
Platelet Response ◽  
Bivalent Metal ◽  
Crotalus Durissus Cascavella ◽  
Crotalus Durissus ◽  
Sepharose 4B ◽  
Phospholipase A2 Inhibitors

Convulxin(Cx), a high molecular weight glycoprotein which was purified by Sephadex G75 and Sepharose 4B chromatography, aggregates platelets of guinea-pigs, rabbits and humans (thresholds of 20-100 pico M for 400,000 platelets/μl). Aggregation and release reaction are plasma-independent, and do not require DFP-fibrinogen (DFP-fib), which increases the platelet response. Cx is not lytic for platelets. Neither ADP scavengers nor aspirin inhibit 2-4 suprathreshold concentrations of Cx. Bivalent metal chelation and PGI2 antagonize Cx. “Thrombinized” platelets lose granular ADP, and still respond to Cx in absence of DFP- fib. Cx-treated platelets are aggregated by ADP, thrombin (T) and arachidonic acid (AA), but are refactory to Cx and to collagen. Cx triggers release of 14C-AA metabolites from rabbit and human platelets, which was inhibited by phospholipase A2 inhibitors. “T-ized” platelets took 14C-AA and failed to release it if stimulated with T, but did so with Cx. Cxi.v.induces thrombocytopenia in rabbits and guinea-pigs, and bronchoconstriction in the latter, which is not blocked by aspirin. Cx is a very effective platelet-stimulating agent, free from proteolytic, amidolytic, esterasic, phospholipase and clotting activities. It probably interacts with T, ADP and thromboxane-independent receptors, and may share a component or a route with the mechanism triggered by collagen.

scholarly journals Anticoagulant and Antithrombotic Properties of Three Structurally Correlated Sea Urchin Sulfated Glycans and Their Low-Molecular-Weight Derivatives

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 304 ◽  
Author(s):  
Ariana Vasconcelos ◽  
Isabela Sucupira ◽  
Alessandra Guedes ◽  
Ismael Queiroz ◽  
Flavia Frattani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Sea Urchin ◽  
Factor Xa ◽  
Activate Factor ◽  
Low Molecular Weight ◽  
Factor Xii ◽  
Sulfated Galactan ◽  
Sulfated Fucan

The anticoagulant and antithrombotic properties of three structurally correlated sea urchin-derived 3-linked sulfated α-glycans and their low molecular-weight derivatives were screened comparatively through various in vitro and in vivo methods. These methods include activated partial thromboplastin time, the inhibitory activity of antithrombin over thrombin and factor Xa, venous antithrombosis, the inhibition of platelet aggregation, the activation of factor XII, and bleeding. While the 2-sulfated fucan from Strongylocentrotus franciscanus was observed to be poorly active in most assays, the 4-sulfated fucan from Lytechinus variegatus, the 2-sulfated galactan from Echinometra lucunter and their derivatives showed multiple effects. All marine compounds showed no capacity to activate factor XII and similar low bleeding tendencies regardless of the dose concentrations used to achieve the highest antithrombotic effect observed. The 2-sulfated galactan showed the best combination of results. Our work improves the background about the structure-function relationship of the marine sulfated glycans in anticoagulation and antithrombosis. Besides confirming the negative effect of the 2-sulfated fucose and the positive effect of the 2-sulfated galactose on anticoagulation in vitro, our results also demonstrate the importance of this set of structural requirements on antithrombosis in vivo, and further support the involvement of high-molecular weight and 4-sulfated fucose in both activities.

Interactions among stimulated human polymorphonuclear leucocytes, released elastase and bronchial antileucoprotease

1988 ◽  
Vol 75 (1) ◽  
pp. 53-62 ◽  
Author(s):  
J. A. Kramps ◽  
Ch. VanTwisk ◽  
E. C. Klasen ◽  
J. H. Dijkman
Keyword(s):  
Molecular Weight ◽  
Enzymatic Activity ◽  
Active Site ◽  
Proteolytic Enzymes ◽  
Low Molecular Weight ◽  
Polymorphonuclear Leucocytes ◽  
Rapid Loss ◽  
Elastase Activity ◽  
Antitrypsin Activity ◽  
Destructive Processes

1. We investigated the effect of stimulated human polymorphonuclear leucocytes (PMN's) on both the antitrypsin and anti-elastase activity of bronchial antileucoprotease (ALP). 2. Incubation of ALP with stimulated human PMN's resulted in a rapid loss of anti-elastase activity which paralleled that of the antitrypsin activity, suggesting that both inhibitor activities are represented by the same active site. 3. The myeloperoxidase-oxidizing system was found to be responsible for the inactivation of ALP. 4. The oxidized inhibitor was unable to form stable complexes with PMN elastase but was resistant to breakdown by proteolytic enzymes from stimulated PMN's. 5. It was observed that stimulated cells are capable of releasing elastase which shows full activity in the presence of a large molar excess of ALP. 6. We conclude from this study that stimulated PMN‘s are able to inactivate ALP by which released elastase is able to express enzymatic activity in spite of the presence of this low-molecular-weight inhibitor. Thus, inactivation of ALP by triggered PMN's may contribute to destructive processes in which elastase is thought to be a mediator.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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