Lysozyme characterization

Presence of the ap fold occurs in lysozyme, characterized by hydrophobic association between an amphiphilic helix and a hydrophobic side of a P-sheet. The P-sheets are thought to associate and become the proteolytic resistant core as the a-helical regions become cleaved by proteolysis. ... 

The model systems, discussed here, contain one type of well-defined protein and one type of well-characterized solid surface in an aqueous medium containing one type of low molecular-weight electrolyte. Table 2 summarizes some relevant properties of the proteins. Lysozyme (LSZ)... 

Fields, B.A., F.A. Goldbaum, W. Dall Acqua, E.L. Malchiodi, A. Cauerhff, F.P. Schwarz, X. Ysem, R.J. Poljak, and R.A. Mariuzza. 1996. Hydrogen bonding and solvent structure in an antigen-antibody interface. Crystal structures and thermodynamic characterization of three Fv mutants complexed with lysozyme. Biochemistry 35 15494-15503. 

Hough, R., Pratt, G., and Rechsteiner, M. (1986). Ubiquitin-lysozyme conjugates. Identification and characterization of an ATP-dependent protease from rabbit reticulocyte lysates. J. Biol. Chem. 261,2400-2408. 

Characterization of Enzyme-Substrate Complex by use of CM-Chitin (Carboxymethyl Chitin). CM-chitinwas prepared by carboxymethylation of chitin according to the method of Imoto, Hayashi and Funatsu (13). The ozonized lysozyme (1.3 mg) solutions at different pHs were neutralized with NaOH or HCl to pH 8.0 and the poured into the column (1.5 X 4 cm.) containing white cotton-like Cm-chitin ( 65 mg.), which was equilibrated with 0.1 M Tris-Cl buffer pH 8.0. Aliquots were eluted first with 0.1 M Tris-Cl pH 8.0 and then with 0.2 M HAc. The absorbance of the fractions was measured spectrophotometrically at 280 nm. 

Lysozyme was isolated from human milk in 1961 by Jolles and Jolles, who believed that bovine milk was devoid of lysozyme. Milks of many species have since been shown to contain lysozyme and several have been isolated and characterized. Human and equine milks are an exceptionally rich source, containing 130 mg 1 1 (3000 times the level of bovine milk) and about 800 mg l-1, respectively (see Farkye, 1992). 

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... 

It is also safe to say that, because of the great complexity of proteins, even of the simplest, most well-characterized proteins, such as insulin, lysozyme, and myoglobin, and because of the very wide range of proteins present in most physiologic environments, very simplistic hypotheses and mechanisms are generally not very applicable. 

S. Colombie, A. Gaunand, M. Rinaudo, and B. Lindet, Irreversible lysozyme inactivation and aggregation induced by stirring kinetic study and aggregates characterization, Biotechnol. Lett. 2000, 22, 277-283. 

Chen, L. L., Wildegger, G., Kiefhaber, T., Hodgson, K. O., and Doniach, S. (1998). Kinetics of lysozyme refolding Structural characterization of a non-specifically collapsed state using time-resolved X-ray scattering./. Mol. Biol. 276, 225—237. 

Enzyme-Degradable Hydrogel. Because lysozyme is a well characterized enzyme, our first choice was a lysozyme-degradable hydrogel (11, 12). The natural substrate for lysozyme is chitin (13). but because chitin is a rigid, hydrophobic material, it is clearly not suitable for this work. The other natural substrates for lysozyme are certain bacterial cell-wall peptidoglycans (13. 

O Brien SM, Sloane RP, Thomas OR, Dunnill P, Characterization of non porous magnetic chelator supports and their use to recover polyhistidine-tailed T4 lysozyme from a crude E. coli extract, I. Biotechnol., 54 53-67, 1997. 

The bird lysozymes c, of which chicken egg white lysozyme (CL) is the most extensively studied example, provide an ideal system to recreate evolutionary intermediates and to study structure-function relationships of reconstructed ancestral proteins. Three major considerations qualify the avian lysozyme system for reconstruction of evolutionary pathways (1) the biochemistry of the enzymes has been extensively studied and well characterized,3,4 (2) there are many natural variants available from other birds, and homologous comparisons can be ensured since lysozymes for all game birds are encoded by a single gene,5 and (3) the three-dimensional structure of CL has been resolved at the atomic level, which allows for structural interpretation of the mutational impact.2,4 Proteins representing the ancestral, evolutionarily intermediate, and derived states of chicken and related bird lysozymes are made and characterized as described below. 

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