Lysozyme induction

Erikson, J.S., Sundaram, S., Stebe, K.J. (2000). Evidence that the induction time in the surface pressure evolution of lysozyme solutions is caused by a surface phase transition. Langmuir, 16, 5072-5078. 

So, T., Ito, H., Hirata, M., Ueda, T., Imoto, T. 2001. Contribution of conformational stability of hen lysozyme to induction of type 2 T-helper immune responses. Immunology 104 259-268. 

Sakato N, Fujio H. Suppression of the delayed-type hypersensitivity response to hen egg white lysozyme (HEL) by HEL peptides in a genetically high-responder monse strain evidence for requirement of the loop structure for induction of suppressor T cells. Cell Immunol 1986 100 66-78. 

For many proteins a time lag of surface tension changes is observed after the formation of a fresh surface. De Feijter Benjamins (1987) defined this time lag as induction period. Wei at al. (1990) discussed the induction period of several proteins, such as cytochrome-c (CYTC), myoglobin (MYG), superoxide dismutase (SOD), lysozyme and ribonuclease-A. Induction periods of up to 25 minutes are observed at low concentrations, as one can see in Fig. 5.38 for three of the five studied proteins. 

Similar induction times were observed for low lysozyme, P-casein and HA concentrations at the aqueous solutions/air interface (for example Douillard et al. 1994, Xu Damodaran 1994). While P-casein shows an induction time of less than 10 minutes, the time lag for lysozyme amounts to about 1 hour (Graham Phillips 1979a cf. Fig. 5.39). 

Crystallization experiments carried out on hen egg white lysozyme (HEWL) demonstrated that, under comparable or even lower supersaturation ratio, induction times for protein crystals grown on polypropylene membranes are lower than those reported in literature for conventional vapor diffusion techniques (Di Proflo et al. 

The induction of cytotoxic macrophages was enhanced by an increase of negative charge at 0-6 and decreased by further modification at 0-3 of the glucopyranose-N-acetyl residue of 0-(carboxy-methyl)chitins (Nishimura et al. 1986). 0-(Carbo-xymethyl)chitins had a minor effect on mitogenic activity that was independent of the site of modification partially N-deacetylated chitins had httle activity. Although there was remarkable enhancement of accessibihty to lysozyme upon modification at 0-6 of the glucopyranose-N-acetyl residue, the accessibihty was decreased by further substitution of 0-3. 

Fig. 2. Low-field region of the proton decoupled natural abundance spectrum of HEW Lysozyme (a) 30 °C, 53000 transients (b) 20 °C, 76000 scans (c) difference spectrum obtained by subtraction of normalized free induction decays of b and a followed by Fourier transformation. See details under Materials and Methods .

STAGE I Water and lysozyme permeate into the chitosan structme followed by induction of swelling. Ihe degradation starts when the lysozyme cleaves -(1 4) glycosidic bonds to produce low-MW chitosan, chito-oligomers, and N-acetyl-D-glucosamine residues. Ihe low-MW fragments remain in the bulk till they reach a smaller size to get dissolved in the medium. 

---