Lysozyme Activity

M (altered lung macrophage function including decreased phagocytosis, increased production of oxygen radicals, and increased LDH and lysozyme activities)... 

Goven, A.J., S.C. Chen, L.C. Fitzpatrick, and B.J. Venables. 1994. Lysozyme activity in earthworm (Lumbricus terrestris) coelomic fluid and coelomocytes enzyme assay for immunotoxicity of xenobiotics. Environ. Toxicol. Chem. 13 607-613. 

The effect of ozone on lysosomal enzymes has been studied by a number of investigators. Ozone has been clearly shown to inactivate lysozyme in vitro, but the effects of inhaled ozone on the activity of lysozyme appear to depend on the pulmonary fraction under study. Holzman et al. reported that exposure of rabbits or mice to ozone resulted in a decrease in the lysozyme activity of bronchopulmonary lavage samples. The effect was linearly related to product of ozone concentration and duration of exposure, although relatively high concentrations of ozone (2.0-S.S ppm) were used in this acute-exposure experiment (1-4 h). The authors also reported that alveolar cells present in the bronchial lavage of rabbits exposed to ozone at 10 ppm for 3 h had a decrease in the rate of lysosomal... 

Similarly, Chow et al. observed an increase in the lysozyme activity of a soluble lung fraction and of plasma after continuous exposure of rats to ozone at 0.8 ppm for 8 days. However, no difference in lung or plasma lysozyme activity from control values was present in rats continuously exposed to 0.2 or 0.5 ppm or intermittently exposed (0.2-0.8 ppm, 8 h/day for 7 days). Histochemical evidence of an increase in lung acid phosphatase, a lysosomal enzyme, has also been reported. ... 

The determination of the lysozyme activity using the bacterial electrode (see p. 139) can also be used for immuno-analysis of biotine and avidine. The determination is based on the inhibition reaction of avidine with the biotine-lysozyme conjugate. After the reaction, the conjugate is no longer capable of dissolving the cell wall of the bacteria. The determination of biotine is similar [15]. 

Enzymic Activity. Lysozyme activity was determined by following the rate of lysis of dried Micrococcus lysodeikticus cells according to the method of Shugar ( ). Assays were run at room temperature in O.IM phosphate buffer pH 7.0, with an enzyme concentration of about 0.05 mg/ml. A solution of native lysoz3mie at the same protein concentration was always assayed as standard, along with ozonized lysozymes. 

Figure 2. pH dependence of native arid ozonized lysozyme activity. Volumes of 1.0 ml of O.IM buffer containing 1.91 mg lysozyme were exposed to a gas stream of Oj/O at a flow rate of 20 ml/min for 8 min. Ozone delivery was 1.5 nmoles/min. Samples were assayed at the different pHs as described in Materials and Methods. 

Johansson A, Lundborg M, Skog S, et al. 1987. Lysozyme activity in ultrastmcturally defined fiactions of alveolar macrophages after inhalation exposure to nickel. Br J Ind Med 44 47-52. 

Kassim, 0.0. and Richards, C.S. (1978a) Schistosoma mansoni lysozyme activity in Biomphalaria glabrata during infection with two strains. Experimental Parasitology 46, 213-217. 

The assay principle is straightforward the clearance of a Micrococcus hocus suspension caused by lysozyme is monitored at 450 nm and compared to a lysozyme standard of known activity. Expression of lysozyme activity in absolute terms is dependent on the substrate sensitivity. Moreover (he light scattering effect of the suspension is determined by the optical geometry of (he spectrophotometer. Therefore, absolute turbidity values can only be obtained by calibration of the apparatus with a standard of known turbidity. 

The culture is harvested by centrifugation at 5000 g and 4° at peak production. Lysozyme activity, which is monitored by the standard turbidity assay of culture supernatant (described in a later section), typically reaches its peak after 5 to 7 days of growth in rich medium. For inactive mutants, the peak of lysozyme secretion is estimated as 12 to 24 hr after the yeast cell density (monitored by A6S0) reaches its peak. 

Twenty-five 1-ml fractions of the eluent are collected and assayed for lysozyme activity. The fractions containing lysozyme activity (typically 6) are pooled. 

Flarada M. 1977. Photochemical smog and tear fluid. [Effects [of smog] on pH, volume, and lysozyme activity of tear fluid.] Nipon Ganka Gakkai Zasshi 81.215- 286. (Japanese)... 

Application and Principle The purpose of this procedure is to determine the lysozyme activity in purified lysozyme preparations derived from animal or microbial sources. The assay is based on the rate of decrease in absorbance at 450 nm, attributed to the lysis of Micrococcus lysodeikticus by lysozyme. The decrease in absorbance is measured using a UV/V spectrophotometer equipped to control the sample temperature at 25°. 

Shugar, D. 1952. The measurement of lysozyme activity and the ultra-violet inactivation of lysozyme. Biochimica et Biophysica Acta. 8 302-309. 

Lipase (Microbial) Activity for Medium- and Long-Chain Fatty Acids, (S3)105 Lysozyme Activity, (S3)106 Maltogenic Amylase Activity, 804 Milk-Clotting Activity, 805 Pancreatin Activity, 805 Pepsin Activity, 807 Phospholipase A2 Activity, 808 Phytase Activity, 808 Plant Proteolytic Activity, 810 Proteolytic Activity, Bacterial (PC), 811 Proteolytic Activity, Fungal (HUT), 812 Proteolytic Activity, Fungal (SAP), 813 Pullulanase Activity, 814 Trypsin Activity, 814 Enzyme Assays, 786 Enzyme-Hydrolyzed (Source) Protein,... 

Lysozyme Activity, Methods for Determination of (Crossowicz and Ariel). 29 435... 

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