Lysozyme synthesis

Lysozyme or muramidase, is an enzyme that catalyses the hydrolysis of the peptidoglycan layer of bacterial cell walls. The urinary excretion of lysozyme increases during urinary tract infections, proximal tubular damage, and excessive endogenous lysozyme synthesis that overwhelm the absorption capacity of the proximal tubule. 

Human monocytes and mouse peritoneal macrophages have been shown to synthesize and secrete large amounts of lysozyme. Synthesis of the enzyme was rapidly inhibited by cycloheximide and less rapidly by colchicine. The physicochemical properties of this lysozyme were reported. 

ScHWEiGER et al., 1972). And although lysozyme messenger shows almost no decay at all, in vivo lysozyme synthesis stops. Both, translational control of available messenger RNA and a differential change in the messenger decay rates seem to be involved. This control seems different from that responsible for the mechanism of shut-off of host translation. 

In the DEAE system the protein fraction is obtained by chromatography of the supernatant Si 00 on DEAE-cellulose. There are differences in the saturating amounts of the protein fraction for synthesis of various enzymes. Thus, although maximal T7 lysozyme synthesis is reached with 60 [xg protein per standard reaction (0.050 ml), for maximal ligase formation slightly more is necessary (90 [xg) (Fig. 10) and maximal synthesis of T7 RNA polymerase needs more than 140 (xg protein fraction. (For maximal leucine incorporation as much as 200 [xg protein fraction is needed.) The reasons for these differences are unknown. 

T3 and T7 Lysozyme. T3 and T7 lysozyme synthesis under the direction of the corresponding DNAs was performed in a DEAE system. The product consists of free enzyme and most probably ribosome-bound enzyme based... 

Dambly, C., Couturier, M., Thomas, R. Control of development in temperate bacteriophages. II. Control of lysozyme synthesis. J. molec. Biol. 32, 67-81 (1968). 

Gold, L. M., Schweiger, M. Control of j5-glucosyltransferase and lysozyme synthesis during T4 deoxyribonucleic acid-dependent ribonucleic acid and protein synthesis in vitro. J. biol. Chem. 245, 2255-2258 (1970). 

Blake CC, Koeniz DF, Mair GA, North AC, Phillips DC, Sarma VR. Structure of hen egg-white lysozyme. A three-dimensional Fourier synthesis at 2 Angstrom resolution. Nature 1965 206 757-61. 

M4. Meillet, D., Belec, L., Celton, N., Gervais, A., etal, Intrathecal synthesis of -2-microglobuUn and lysozyme Differential markers of nervous system involvement in patient infected wifli human immunodeficiency virus. Eur. J. Clin. Biochem. 31, 605—519 (1993). 

Figure 4. Photograph of a lysozyme model showing the relative positions of the residues constituting antigenic sites 1 and 2. The side chains of the residues in the sites are outlined, those making up site 1 are speckled areas, while those constituting site 2 are shown as dotted areas to avoid confusion. The preferred direction of site 1 (at least by surface-simulation synthesis) is Arg-125 to Lys-13. Site 2 also had a preferred direction (Trp-62 to Asp-87) ...

Let us go back to the problem of the formation of specific macromolecular sequences. The core of the problem lies in the fact that the synthesis of such copoly-meric sequences, like lysozyme or t-RNAP, is not under thermodynamic control. How can we then conceive their formation under prebiotic conditions, i.e., in a time where only spontaneous reactions were possible ... 

Biophysical characterization showed that a single HRP II protein bound 17 molecules of heme [35]. In an in vitro heme polymerization assay, HRP II promoted the synthesis of hemozoin, while controls, such as the proteins bovine serum albumin and lysozyme or the homopeptides polyhistidine, polylysine, and polyasparagine, did not. FT-IR analysis of the reaction product showed the characteristic vibrations of hemozoin. The polymerization activity had a pH maximum near 4.0, which dropped off precipitously near the pKa of histidine. The heme polymerization... 

Luckarift HR, Dickerson MB, Sandhage KH et al. (2006) Rapid, room-temperature synthesis of antibacterial bionanocomposites of lysozyme with amorphous silica or titania. Small 2 640-643... 

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