Enzyme release

Stabilizes lysosomal membrane and prevents the release of proteolytic enzymes released during the inflammatory process... 

Xylans as true homopolymers occur in seaweeds of the Palmariales and Nemaliales, however, their backbone consists of Xylp residues linked by -(1 3) (Type X3, Fig. la) or mixed -(1 3, 1 -> 4)-glycosidic linkages (Type Xmy Fig. lb). They are assumed mainly to have a structural function in the cell-wall architecture, but a reserve function cannot be ruled out [4]. From the microfibrils of green algae (Siphonales) such as Caulerpa and Bryop-sis sp., X3 was isolated and the structure confirmed by methylation analysis, C-NMR spectroscopy [7], as well as by mass spectrometry of enzymically released linear oligosaccharides up to a degree of polymerization (DP) of... 

Neutrophils represent an ideal system for studying osmotic effects on exocytosis. Stimulation of cytochalasin-B-treated neutrophils with the chemotactic peptide Jlf-formylmethionyl-leucyl-phenyl-alanine (FMLP) results in a rapid compound exocytosis up to 80% of lysosomal enzymes are released within 30 s (9-14). Secretion appears to be triggered by a rise in the level of cytosolic free calcium (15-18) promoted in part by entry of extracellular calcium through receptor-gated channels and in part by release of calcium that is sequestered or bound at some intracellular site (19-21). In this presentation, we augment our previously published data (22,23), which demonstrates that lysosomal enzyme release from neutrophils is inhibited under hyperosmotic conditions and that the rise in cytosolic calcium preceding secretion is inhibited as well. 

Figure 4. Effect of hyperosmolality on lysosomal enzyme release from rabbit neutrophils. Cells were preincubated 10 min at 37 C in either regular HEPES buffer at 320 mosmol/kg ( ) or in HEPES buffer with 0.3-M sucrose at 680 mosmol/kg ( ), 5 Mg/mL cyto-chalasin B was added, cells were stimulated with FMLP, and p-glucuronidase was released into the medium during a 6-min period measured.

Figure 5. Inhibition of lysosomal enzyme release from neutrophils by increased osmotic strength. Cells were preincubated for 10 min at 37°C in regular buffer containing no additions (o), or containing sodium sulfate ( ), sodium HEPES ( ), or sucrose ( ) to increase the osmotic strength. Cells were treated with cyto-chalasin B (5 arid FMLP (10" M) and p-glucuronidase was...

Finally, the A. aculeatus preparation was found to contain an enzyme releasing the dimer B-Xylp-(l-3)-GalAj, from a soluble soy cell wall polysaccharide. The enzyme was partially purified and appeared to be active towards saponified MHR and gum tragacanth as well. It was concluded that this enzyme degraded the xylogalacturonan part in MHR by an exo-fashion. 

Enzymic release of ferulic acid from sugar beet pulp using a specific esterase from Aspergillus niger... 

Several scouting experiments were performed to find the best pH conditions. Figure 3 reports the ratio between the PG specific activity measured after the purification procedure (ASf) and the initial PG specific activity (ASi). At pH 3.5, the microspheres are able to remove from the broth the major part of the protein without PG activity, thus providing a four time increase of the enzyme specific activity. The purified PG from Kluyveromyces marxianus was immobilised following the above procedure. Batch reactions in the packed bed reactor were done to evaluate the biocatalyst stability. After an initial loss, due to enzyme release, the residual PG activity reaches a plateau value corresponding to about 40% of the initial activity. Probably, some broth component interfered during the immobilisation reaction weakening the protein-carrier interactions. 

Hearse, D.J., Humphrey, S.M. and Chain, E.B. (1973). Abrupt reoxygenation of the anoxic potassium arrested perfused rat heart a study of myocardial enzyme release. J. Mol. CeU. Cardiol. 5, 395-407. 

Furthermore, depletion of hepatic GSH induced chemically or by fasting augmented hepatic I/R-induced enzyme release and promoted lipid peroxidation (Jennische, 1984 Stein et al., 1991) Benoit et al. (1992) have used portacaval-shunted rats as a model of chronic hepatic ischaemia, and were able to show decreases in total levels of SOD and xanthine dehydrogenase, but no significant change in catalase or glutathione peroxidase. 

Medications aimed at decreasing pancreatic enzyme release (e.g., somatostatin), nasogastric suction, and anticholinergic medications have all failed to show benefit in the treatment of acute pancreatitis. 

Hydrolytic enzymes released from eosinophil granules (which are... 

In fact, after 5 reaction cycles the entrapped lipase shows a residual activity of the 60%, with respect to the total leaching that occurs after 3 or 2 reaction cycles for the adsorbed enzyme (Figure 2). Moreover, with respect to the biodiesel total productivity of the free lipase, the entrapped RML shows, after 5 reaction cycles, a value that is almost 6 times higher (1.62 mg FAME /mg Enz h and 0.28 mg FAME /mg Enz h, respectively for entrapped and free lipase). Concerning the stability of the inorganic matrix that covers the enzyme, after tested reaction cycles (five), mesoporous structure remains unaltered an stable (Figure 3). This indicates that the lipase leaching is due to the enzyme release and not to the collapse of matrix. 

Methods utilizing the determination of enzymically released methanol, either after distillation,59,64 or directly in the reaction mixture,109 just like the method of manometric determination of the carbon dioxide released from hydrogen carbonate buffer,55 have not found... 

Another method is based on the same principle,112 in which the [14C]labelled methyl ester of D-galacturonan is prepared by esterification of pectic acid with [,4C]diazomethane. In the course of the enzymic de-esterification, aliquots are removed, and the unreacted substrate is precipitated with acidified ethanol or 1-propanol. After centrifugation, the labelled methanol in the supernatant liquor is determined in a liquid scintillation counter. An advantage of this method lies in the possibility of using, as substrates, short-chain oligo-D-galactosiduronates partially esterified with [14C]methanol. These substrates, beginning with the trisaccharide, are not soluble in 1 4 80% phenol-diethyl ether, which is used for the extraction of enzymically released, labelled methanol. 

Isolated liver segments from starved rats exposed to 100 mg KCN/L Oxygen consumption reduced 80%, and evidence of hepatotoxicity as judged by enzyme release, glutathione depletion, and calcium accumulation in liver. Hepatotoxicity prevented by feeding rats fructose 39... 

Endotoxin activates complement, which then augments the inflammatory response through stimulation of leukocyte chemotaxis, phagocytosis and lysosomal enzyme release, increased platelet adhesion and aggregation, and production of toxic superoxide radicals. 

Other inorganic and organic compounds are brought into solution by the decomposition of their parent materials. Rocks and minerals will be decomposed by physical, biological, and chemical mechanisms. Enzymes released into the soil solution by microorganisms will decompose insoluble organic... 

Mn superoxide dismutases are found in both eubacteria and archaebacteria as well as in eukaryotes, where they are frequently found in mitochondria. They (Figure 16.1) have considerable structural homology to Fe SODs both are monomers of 200 amino acid and occur as dimers or tetramers, and their catalytic sites are also very similar. They both catalyse the two-step dismutation of superoxide anion and, like the Cu-Zn SODs, avoid the difficulty of overcoming electrostatic repulsion between two negatively charged superoxide anions by reacting with only one molecule at a time. As in the case of Cu-Zn SOD, a first molecule of superoxide reduces the oxidized (Mn3+) form of the enzyme, releasing... 

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