Showing papers on "Chitinase published in 1974"

Chitinase in goat serum. Preliminary purification and characterization.

Abstract: 1. A glycol-chitin-splitting enzyme without lysozyme (muramidase) activity was found in serum from various animals. Goat, cow, hen, sheep and pig possessed high activity. No activity was found in serum from man, monkey, horse, dog, cat, rabbit, guinea-pig or hamster. 2. Glycol chitin has been used as a substrate in purification and characterization. A viscosimetric assay with the use of this substrate was found to be a convenient method. 3. By means of ammonium sulphate fractionation of goat serum and subsequent gel chromatography a 100-fold purification of the enzyme was obtained. 4. The purified enzyme has its optimal activity around pH 1.65 with glycol chitin as a substrate and, when incubated at 50 °C for 60 min, the optimal stability is in the pH interval 3.5–6.5. The pI determined by isoelectric focusing is 4.85 and the molecular weight assessed by gel chromatography is around 60000. 5. The purified goat serum enzyme degrades colloidal chitin with an optimum at pH 5.5 and is thus defined as a chitinase. Goat anti-human lysozyme serum does not inhibit the purified chitinase. 6. To elucidate the origin of the serum chitinase, the concentration of the enzyme was determined in various organ tissues and body fluids. The highest activity with the exception of serum was found in the wall of the fourth stomach of goat and cow.

Enzymic degradation of septa in hyphal wall preparations from a monokaryon and a dikaryon of schizophyllum-commune

Abstract: SUMMARY: Hyphal wall preparations of Schizophyllum commune were treated with enzymes and the dissolution of wall components and the degradation of septa were simultaneously recorded. The breakdown of the alkali-insoluble R-glucan (β-1,3, β-1,6-glucan) by R-glucanase was not influenced by the presence of chitinase but the breakdown of chitin by chitinase was stimulated by R-glucanase. The combination of R-glucanase and chitinase also had a synergistic effect on crosswall degradation. This indicates that the crosswalls contain both chitin and R-glucan, the chitin probably embedded in R-glucan. S-glucan (α-1,3-glucan), a prominent component of the lateral walls, is apparently absent from the crosswalls. The septal swellings consist of material that is alkali soluble but different from S-glucan. Crosswalls in hyphal wall fragments from a dikaryon were much more resistant to cnzymic dissolution than those in hyphal wall fragments from a monokaryon. Such a difference could not be noted in the dissolution of wall components. The results are discussed with regard to their significance for sexual morphogenesis in Schizophyllum commune.

Adsorption and activity of chitinase on kaolinite

Abstract: Chitinase is adsorbed on kaolinite below the isoelectric point of the enzyme, pH 6.8. Maximum adsorption is reached below pH 4.6. The amount of chitinase adsorbed to kaolinite depends on the concentration and on the ratio of enzyme to kaolinite. Adsorption results in reduction of chitinase activity. the extent of which depends on the amount of kaolinite present, on pH, and on the length of exposure time. Upon sorption of chitinase on kaolinite the optimal pH for activity is increased from pH 4.7 to 5.7.

Characterization of chitinases from haemolymph and cell cultures of cockroach (Periplaneta americana)

Abstract: 1. 1. Two chitinases have been characterized in the haemolymph and in cell cultures of the cockroach. 2. 2. Both enzymes showed the same chromatographic and electrophoretic behaviour when purified from the two different sources. 3. 3. The purified enzymes presented no lytic activity against cell suspensions of Micrococcus lysodeikticus . 4. 4. The haemolymph collected from females carrying ootheca was devoid of any chitinase activity.

Effect of chitinase complex on the antigenicity and chemistry of yeast-form cell walls and other fractions of Histoplasma capsulatum and Blastomyces dermatitidis

Abstract: Cell walls isolated from the yeast forms of 2 strains each of Histoplasma capsulatum and Blastomyces dermatitidis were treated for up to 3 weeks with an enzyme complex containing chitinase and β-1:3-glucanase. The release of glucose, protein, and amino-sugars from the cell walls was monitored. Cell walls of H. capsulatum lost about 25% of their dry weight as glucose, about 19% as amino-sugar (mainly free N-acetyl glucosamine), and about 6% as protein. Cell walls of B. dermatitidis lost only about 1% of their dry weight as glucose, about 22% as amino-sugar (mainly chitobiose), and about 6% as protein. Electron microscopy of intact yeast-form cells showed them to be extensively degraded by the enzyme complex. Complement fixation (CF) tests indicated that the enzyme treatments caused no substantial change in the antigenic specificity or sensitivity of the cell walls. However, concentrated culture filtrates of B. dermatitidis and the soluble fraction of H. capsulatum cell walls after chitinase treatment, show...

Studies on a strepzyme capable of obtaining protoplasts from Fusarium culmorum conidia

Abstract: The effect of several substances on extracellular β-1,3- and β-1,6-glucanases and chitinase production by Streptomyces FL44 has been studied, and β-1,6-glucanases were found in every culture filtrate studied, whilst chitinase was only found when Streptomyces was growing in media containing chitin. Protoplast liberation from Fusarium culmorum (W. G. Smith) Sacc. conidia was observed by using as lytic enzyme, the culture filtrate obtained by growing Streptomyces FL44 in a chitin-laminarin liquid medium with 0·5 m potassium chloride as osmotic stabilizer. Although the lytic activity was mainly in the culture filtrate, considerable internal lytic activity was found in the mycelium of Streptomyces FL44.