scholarly journals Formation of high molecular weight material by free-living marine bacteria

1994 ◽  
Vol 111 ◽  
pp. 129-135 ◽  
Author(s):  
A Heissenberger ◽  
GJ Herndl
1977 ◽  
Author(s):  
K. A. Rickard ◽  
T. Exner ◽  
H. Kronenberg

Gel filtration of human plasma cryoprecipitate on Sepharose 2B indicated the molecular weight of factor VIII coagulant activity (VIIIc) to be significantly greater than that found in antihaemophilic concentrate. Polyethylene glycol at 3% concentration precipitated approximately half of the VIIIc from cryoprecipitate. This activity eluted as high molecular weight material on gel filtration. The addition of more polyethylene glycol to a concentration of 8% precipitated most of the remaining VIIIc from cryoprecipitate. This activity appeared to be of significantly lower molecular weight, approximately corresponding in elution volume to that observed for antihaemophilic concentrate. The possibility that an antibody to VIIIc generated in a patient treated with cryoprecipitate might be directed against the higher molecular weight form of factor VIII was investigated. However, no significant differences between the higher and lower molecular weight forms of factor VIII either in stability or in reactivity with human antibody to factor VIII were found.


Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 502-513 ◽  
Author(s):  
GE Davies ◽  
J Palek

Abstract We have examined platelet protein organization by treatment of intact resting or thrombin-activated platelets with two cross-linking reagents, diamide or dithiobis(succinimidyl propionate) (DTSP). Cross- linked complexes were separated by polyacrylamide gel electrophoresis in the absence of reducing agent and their composition determined after reductive cleavage and analysis in a second-dimensional gel. The most prominent cross-linked species produced by diamide treatment of of resting platelets are (A) cytoskeletal protein homopolymers, such as myosin heavy chain dimer and actin oligomers, and (B) high molecular weight material consisting of homo- or heteropolymers of cytoskeletal proteins and 230,000, 170,000, 100,000, 55,000, and 52,000 dalton proteins. DTSP treatment forms similar complexes and also cross-links membrane glycoproteins IIb and III into high molecular weight material. Thrombin activation of platelets before treatment with diamide or DTSP results in increased cross-linking of myosin and increased incorporation of several proteins, particularly myosin and glycoproteins IIb and III, into high molecular weight material. The results provide evidence for reorganization of cytoskeletal and membrane proteins during platelet function.


1961 ◽  
Vol 34 (1) ◽  
pp. 101-118 ◽  
Author(s):  
V. E. Gul

Abstract In connection with the wide distribution of high molecular weight compounds and the great successes in the field of synthesis of these materials, the study of the general principles of the processes of irreversible deformation and rupture of high polymer materials may be included among the important tasks of science and technology. In some cases it is desired to increase to the maximum the strength of the high molecular weight material, as for example in preparing articles from synthetic fibers, rubbers, plastics, etc., while on the other hand in others an increase in strength is undesirable. Thus, for example, food products, into whose composition high molecular weight materials are introduced, should naturally not be too strong. The preparation of reclaim from used rubber articles includes grinding. Here it is attempted to find such a combination of grinding conditions that will proceed with the minimum consumption of energy. In order to have the possibility of increasing or decreasing the strength of the high molecular weight substances, it is necessary to clarify the mechanism of ruptures and to know what is the relation between the forces of reaction between the structural elements of the material and tensile strength.


1981 ◽  
Author(s):  
G Müller-Berghaus ◽  
J-C Bernhard ◽  
I Mahn

In two consecutive steps, thrombin cleaves the fibrinopeptides A and B from fibrinogen producing des-A fibrin and des-AB fibrin. Labeled des-A fibrin was prepared by batroxobin and labeled des-AB fibrin by clotting of 125I-fibrinogen with thrombin. Fibrin solubilized in buffered urea was mixed with plasma containing 131I-fibrinogen (fibrin:fibrinogen ratio = 1:20). These fibrinfibrinogen mixtures were applied to sepharose CL- 6B columns eq ui librated with buffered plasma (0.0025 M EDTA, 0.1 M NaCl, 0.05 M tris, 0.005 M EACA, 2 AT U hirudin/ml, 500 KIU a protinin/ml, 0.003 M NaN3, pH 7.4). Plasma was used as an equilibration and elution medium to prevent precipitation of fibrin in the columns. At 20°C, labeled des-A fibrin as well as des-AB fibrin were eluted in the void volume as high-molecular weight aggregates (peak A) and separated from m onomeric labeled fibrinogen (peak B). At 37°C, however, des- A fibrin was eluted at the same position as monomeric fibrinogen (peak B), whereas des-AB fibrin was eluted in the void volume as at 20°C. Rechromatography of isolated fractions of peak A and peak B at different temperatures showed that monomeric fibrin isolated at 37°C formed high molecular weight material at 20°C, and high-molecular weight fibrin isolated at 20°C dissociated at 37 ° C. The results suggest that des-A fibrin solubilized in plasma in the absence of calcium ismonomeric at 37°C but forms high-molecular weight aggregates at lower temperature, whereas des-AB fibrin is oligomeric at 20°C as well as at 37°C.


Holzforschung ◽  
2000 ◽  
Vol 54 (3) ◽  
pp. 273-278 ◽  
Author(s):  
E. J. Vilen ◽  
A. B. McKague ◽  
D. W. Reeve

Summary Effluents from the chlorine dioxide bleaching of chemical pulps were characterized with respect to high and low molecular weight material, COD, TOC, elemental composition, and carboxylic acid and methyl ester content. A technique was developed for the quantitative estimation of muconic acid-type structures as moities of the high molecular weight material. The method is based on the use of quantitative 13C NMR and the pH-dependent cyclization of muconic acids in aqueous solution. 20–40 % of the carboxylic acids in the high molecular weight material isolated from bleach plant effluents from three softwood kraft mills were found to exhibit muconic acid-type behaviour.


1997 ◽  
Vol 488 ◽  
Author(s):  
Steven K. Pollack ◽  
Ashebir Fiseha

AbstractThermally-induced polymerization of 1,4-diphenyl-1,2,3-butatriene affords poly(1,4-diphenyl- 2-butyne-1,4-diyl) as a soluble high molecular weight material. Structure is characterized by 13C and vibrational spectroscopy. When treated with base, this material rearranges to a soluble red poly(acetylene) with a unique substitution pattern.


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