Lysozyme products

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

ZENECA has developed a non-solvent based recovery process as an alternative to solvent extraction for the commercial production of poly(3HB) and poly(3HB-co-3V) by A. eutrophus [94,95], In this process the cells were first exposed to a temperature of 80 °C and subsequently treated with a cocktail of various hydrolytic enzymes consisting of lysozyme, phospholipase, lecithinase, the proteinase alcalase, and others. Most of the cellular components were hy-... 

One of the minor by products of the isolation procedure of the disaccharide from lysozyme digests of bacterial cell walls was the tetrasaccharide /i-GIcNAc-G 4)-/i-MurNAc-G 4)-/)-GlcNAc-(l 4)-MurNAc. This structure is readily cleaved by lysozyme, and has proved to be extremely useful in other laboratories for the study of the mechanism of action of the enzyme. 

As indicated in Table 2.1, most of the promoters used in plant tissue culture have been based on the constitutive cauliflower mosaic virus (CaMV) 35S promoter. In contrast, inducible promoters have the advantage of allowing foreign proteins to be expressed at a time that is most conducive to protein accumulation and stability. Although a considerable number of inducible promoters has been developed and used in plant culture applications, e.g. [32-37], the only one to be applied thus far for the production of biopharmaceutical proteins is the rice a-amylase promoter. This promoter controls the production of an a-amylase isozyme that is one of the most abundant proteins secreted from cultured rice cells after sucrose starvation. The rice a-amylase promoter has been used for expression of hGM-CSF [10], aranti-trypsin [12, 29, 38, 39] and human lysozyme [30]. 

Tests allowing precise determination of the conditions to protect the soluble protein, and of the temperature at which the reaction was slow enough for X-ray data collection, were sought. To ascertain the best conditions for the determination of the structure of a productive lysozyme-substrate complex, the hydrolysis of bacterial cell walls and oligosaccharides was investigated both in high-salt solutions and in mixed solvents. 

These results suggest that the crystallographic determination of the structure of a productive enzyme-substrate complex is feasible for lysozyme and oligosaccharide substrates. They also provide the information of pH, temperature, and solvent effects on activity which are necessary to choose the best conditions for crystal structure work. The system of choice for human lysozyme is mixed aqueous-organic solvents at -25°C, pH 4.7. Data gathered on the dielectric constant, viscosity, and pH behavior of mixed solvents (Douzou, 1974) enable these conditions to be achieved with precision. 

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... 

The initial step in the alternative hydrolysis mechanism is protonation of the ring 0i by Glu 35 (Scheme I). Cleavage of the endocyclic C1-O5 bond forms the acyclic oxocarbonium ion intermediate, which is stabilized by Asp 52. Attack by water, cleavage of the C1-O4 bond, and ring closure then lead to the observed products. Existing experimental data on lysozyme hydrolysis are consistent with Scheme I (see references in Post and Karplus ( )). Moreover, distortion of the ring in site D is not required and the antiperiplanar orientation of an exocyclic O4 lone pair orbital relative to the cleaved C1-O5 bond found in the simulation (see section on "Enhancement of a Substrate Conformation Optimum for Catalysis") is in accord with stereoelectronic requirements (1 ). ... 

LysS/LysE an additional chloramphenicol resistant plasmid carries the gene forT7 lysozyme under constitutively active promoters. T7 lysozyme inhibits the activity of T7 polymerase thereby reducing basal (uninduced) polymerase activity/ protein expression. LysE express higher levels of T7 lysozyme for tighter control. pLacI an additional chloramphenicol resistant plasmid carries the gene for high level production of the lac repressor to reduce basal expression. 

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