Depolymerization Products Research Articles

Depolymerisation of Human and Bovine Polymeric Collagen Fibrils

Bovine and human polymeric collagen fibrils were incubated at 37°C over a range of pH with a crude lysosomal enzyme preparation obtained from rat liver. Electron microscopic analysis demonstrated depolymerisation of the fibrils over the pH range 3.5 to 7.5 with the cleavage of the fibrils into short segments, followed by unwinding of the protofibrils and cleavage of the protofibrils into protofibrillar particles. The depolymerisation of polymeric collagen to soluble products was followed by hydroxyproline analysis; the pH optimum for this process was approxi- mately 4.0. The soluble depolymerisation products of bovine polymeric collagen fibrils digested at pH 4.0 were found to be native tropocollagen-like molecules which rapidly aggregated at physiological pH to form intermolecularly cross-linked native type fibrils. No soluble hydroxyproline containing products were produced by this enzyme system at physiological pH, although the cleavage of polymeric collagen fibrils could be observed at the electronmic...

Hemostatic breakdown, fibrinolysis, and acquired hemolytic anemia in a patient with fatal heatstroke: pathogenetic mechanisms.

A patient with fatal heatstroke developed hemorrhagic manifestations and overt hemolytic anemia. Over a period of 10 days, studies of the components of the clotting and fibrinolytic systems were carried out to analyze their roles in the pathogenesis of the hemostatic breakdown. Findings indicated a combination of intravascular defibrination and activation of fibrinolysis, the latter apparently followed by the appearance in the bloodstream of products of depolymerization of fibrin and fibrinogen, with the property of antithrombin anticoagulants. Thrombocytopenia and thrombocytopathy were present. Hemolysis and release of thromboplastic material and fibrinolysokinases into the bloodstream probably were related to tissue injury due to the hyperthermia. A hypothesis of the sequence of events leading to the severe hemostatic breakdown in heatstroke is presented.

Induction and the Regulation of Production of Cellulase by Fungi

SYNTHESIS of cellulases by fungi is considered to be induced by cellulose substrates, or more specifically by their water soluble short chain depolymerization products such as cellobiose1, and occasionally by other disaccharides such as sophorose2 or lactose3. Glucose is considered to invoke an inducer-represser mechanism of regulation of enzyme production when added to cellulose, for it represses the induction of cellulase unless present in extremely small amounts4. But fungi which grow on cellulose alone must also utilize glucose, for the monomer is often reported to be the final product of cellulose depolymerization5,6. The production of cellulase would not be expected to be repressed in these conditions because the organism's rate of glucose utilization would usually be restricted by the relatively slow rate of release of monomer from cellulose. Thus, if glucose were supplied to laboratory cultures as their sole source of carbohydrate at a limited rate, comparable with its slow rate of release from cellulose, then production of the enzyme might well be promoted. We have experimental support for this hypothesis, showing that the production of cellulase is controlled by the organismapos;s rate of metabolism when regulated, for example, by carbohydrate uptake. We have also found that neither cellulose, cellobiose, nor any other sugar is required per se for production of the enzyme.

Analysis of Depolymerization Products of Tempoku Coal (II)

Analysis of Depolymerization Products of Tempoku Coal (II)

Analysis of Depolymerization Products of Tempoku Coal

The petroleum ether extracts of depolymerized Tempoku coal were analysed by gas chromatography . The principal peak detected were 9-methoxyphenyl xanthene, 2-methoxyphenyl benzofuran, dimethoxy diphenylmethan, dimethoxydibenzyl and xanthone.The most abundant derivative of these compounds was 9-(4-methoxyphenyl)-xanthene. Total number of separated peaks was 35.

Prevention and Regression of Atherosclerosis by Peroxidase.

s1 May 1967Prevention and Regression of Atherosclerosis by Peroxidase.Josefina Caravaca, Ph.D., E. Grey Dimond, M.D., F.A.C.P.Josefina Caravaca, Ph.D.Search for more papers by this author, E. Grey Dimond, M.D., F.A.C.P.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-66-5-1035_2 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptA molecular subunit of beef hepatocatalase that exhibits high enzymatic activity as a peroxidase-oxidase and is essentially free of catalatic action has been isolated. The hepatocatalase peroxidase subunit (HCP) is a depolymerization product of hepatocatalase with an estimated molecular weight of 80,000 ± 12,000. It was obtained in the form of a stable, lyophilized, water-soluble powder by a procedure involving alkaline hydrolysis, dialysis, and lyophilization. Like hepatocatalase, HCP is also a porphyrin enzyme. The availability of this preparation has made it possible to study the peroxidatic function of catalase without interference from its catalatic action and to obtain some basic... This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: La Jolla, California PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics 1 May 1967Volume 66, Issue 5Page: 1035-1035KeywordsAtherosclerosisEnzymesMedical dialysisPeroxidasesPorphyrins Issue Published: 1 May 1967 PDF downloadLoading ...

Poly‐1,6‐Diselenahexamethylene, 1,2‐diselenane, and their effects on vinyl polymerizations

AbstractPoly‐1,6‐diselenahexamethylene has been prepared, and some of its properties and those of its depolymerization product, 1,2‐diselenane, have been studied. Depolymerization probably occurs by a free‐radical mechanism. The effects of these organoselenium compounds on the thermal polymerization of styrene, methyl methacrylate, vinyl acetate, and acrylonitrile at 60°C. in the presence and absence of 2,2′‐azobisisobutyronitrile and on the direct photopolymerization of these vinyl monomers at 25°C. has been examined. Various reaction mechanisms are suggested to explain the experimental results.

Isolation of Certain Compounds from Depolymerization Product of Brown Coal

The benzene-soluble fraction of brown coal depolymerized in phenol with p-toluene sulphonic acid as catalyst was methylated and fractionated by liquid chromatography. 2-(4-methoxyphenyl)-benzofuran, 9-(4-methoxyphenyl)-xanthene, 9-(2-methoxyphenyl)-xanthene and xanthone were identified, suggesting that the structures-CH2-O=CH-, -CH=C-OH-, etc.may exist in the brown coal.

Contrast staining and quantitative determination of mucopolysaccharides on filter paper by means of colloidal iron.

The contrast between the Prussian blue color of the mucopolysaccharide spots and paper background was increased by differentiation of the paper strips (dyed in acid colloidal iron solution made up in 60% ethanol) with thioglycolic acid. Thus the trivalent iron bound to the paper background was reduced but that adsorbed by the mucopolysaccharides was precipitated as ferric ammonium thioglycolate. This procedure was found to stain equally well acid (including sulfated) and neutral mucopolysaccharides, even though these varieties exhibited different staining properties by the periodic acid-Schiff and toluidine blue dyeing procedures. Staining of different depolymerization products of hyaluronate was little influenced by their chain lengths. Quantitative determination of the mucopolysaccharide content of the spots was performed by elution of ferrocyanide with hot sodium hydroxide and measuring of the Prussian blue color of the extracts, developed on acidification and addition of FeCl3.

Gas‐liquid chromatography in a plastics analytical laboratory

AbstractThis report gives an account of the application of gas‐liquid chromatographic methods to the general work of a plastics analytical laboratory. Particular attention is paid to the examination of monomers, of depolymerization products obtained from polymers, and of adhesives. The use of dinonyl sebacate as the stationary liquid phase in a particular problem involving the determination of small amounts of methylcyclohexane in light petroleum (boiling range 60–80°) is described.

Buildings have pulses : J.J. Creskoff. ( Civil Engineering, Vol. 7, No. 9)

When dry soil is re-wet there is a pulse of C mineralization. It is likely that the pulse of mineralization is fuelled by soluble C that accumulates as soil is drying. When soil is drying soluble C could accumulate as products of exo-enzyme mediated depolymerisation (i.e. protein amino acids and small carbohydrates) in the extracellular fraction of the soil (i.e. adsorbed and in free solution). Alternatively there could be an accumulation of osmolytes within the microbial biomass. To test whether extracellular depolymerisation products and/or microbial osmolytes accumulate as soil dries, soil from a Themeda triandra grassland was dehydrated and then depolymerisation products and osmolytes were quantified by capillary electrophoresis-mass spectrometry and gas chromatography–mass spectrometry. A secondary aim of this experiment was to determine if the response of soil to drying is the same when soil is dehydrated rapidly in the laboratory as when an intact soil containing plants is slowly dehydrated by withholding water from large (200 L) mesocosms.The responses of soil to dehydration differed between lab incubations and mesocosms, despite involving the same soil being dehydrated to the same final water content. When soil was dehydrated slowly in 200-L mesocosms the accumulation of osmolytes was more quantitatively significant than accumulation of depolymerisation products, whereas when soil was dehydrated more rapidly in lab incubations there was negligible accumulation of osmolytes but large accumulation of depolymerisation products. This study has highlighted that when soil dries the accumulation of osmolytes within microbial biomass and depolymerisation products within the extracellular fraction of soil are both quantitatively important and likely underpin the flush of soil CO2 efflux when dried soil is re-wet.